Attachment No. B.9 (extract from Safety Report prepared ...

Attachment No. B.9 (extract from Safety Report prepared under SI 476 of 2000)

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:09

0

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number:1.0.3 3 111 2/05

Section 5 = Identification 8i

Analysis of Accidental Risks

Page 1 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:09

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number:l.O.3 3 111 2/05

1

dunea J

~~ ~ ~

1 Identification & Analysis of Accidental Risks

1.1.1 Introduction

A major hazard as defined in Regulation S.1476 of 2000 is

"The intrinsic property of a dangerous substance or physical situation, with a potential for creating damage to human health and/or the environment"

The purpose of the Hazard Identification and Risk Assessment process is to identify all potential major accident Hazards in each area of the site where dangerous substances are held processed or stored. The assessment is carried out to determine the likelihood, severity and consequences of major accident scenarios. The methodology used is based on Preliminary Hazard Analysis, which involves a systematic assessment of the risk levels of all operations in order that effective management of the facility can occur. This method gives a semi quantitative assessment of the overall level of risk presented in each case.

An assessment of the existing measures in place and recommendations for new measures for each major accident scenario was carried out. This assessment shows that Dynea is proactive in providing all necessary measures to protect both man and the environment from the consequences of each major accident scenario arising from its operations at the facility at Marino point.

This method of Preliminary Hazard Analysis (PHA) is an approved risk assessment technique, which is approved by Institute of Chemical Engineers (IChemE). In addition to the PHA study which focuses specifically on major accident scenarios, HazOp studies are being carried out on all plant and equipment.

1.1.2 2004/2005 HazOp Study

In late 2004 Dynea Ireland reviewed the HazOps completed on the plant in 1995/1996. These HazOps were shown to be incomplete. It was decided in 2004 that a complete HazOp of the plant would begin. This process is ongoing. It is hoped that this process will be finished by March 2006. A summary of the HazOp procedure is given below.

A HazOp (1) study identifies hazards and operability problems. The study involves investigating how the plant might deviate from the design intent. If, in the process of identifying problems during a HazOp study, a solution becomes apparent, it is recorded as part of the HazOp result. HazOp is based on the principle that HazOp team members with different backgrounds can interact and identify more problems when working together, than when working separately and combining their results.

The HazOp concept is to review the plant in a series of meetings, during which a multidisciplinary team methodically assesses the plant design, following the structure provided by the guide words. The process requires that all team members participate. The team focuses on specific points of the design (called "study nodes"), one at a time. At each of these study nodes, deviations in the process parameters are examined using the guide words. The guide words are used to ensure that the design is explored in every conceivable way.

Each guide word is applied to the process variables at the point in the plant (study node) which is being examined. For example:

1 HAZOP Guide to Best Practice, IChem E (UK), EPSC, CIA, 2000

Page 2 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

. . .. . . . .

Guide Words NO MORE

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: issue Date: Number:1.0.3 3 1 I1 2/05

Parameter Deviation FLOW NO FLOW

PRESSURE HIGH PRESSURE

I

dynea

These guide words are applicable to both the more general parameters (e.g., react, transfer) and the more specific parameters (e.g., pressure, temperature).

With the general parameters, meaningful deviations are usually generated for each guide word. It is not unusual to have more than one deviation from the application of one guide word.

The results of the discussions are recorded on the standard HazOp report form. This form details recommended actions for improvements and assigns a member of the team to complete the action. A summary of HazOp technique is given in appendix 5. The makeup of the HazOp team is detailed in section 1 .I .5 and contains the same members as PHA team.

0 1.1.3 Risk Assessment

In 2005 Dynea purchased Risk Assessment (RiskSase) software from Crest Solutions who have developed this new Risk assessment software. This software allows the user to schedule risk assessment occurrence and to track the implementation of control measures generated. The following is a summary of how the risk assessment software works. Risk questions are developed, and downloaded to a pocket PC. The Pocket PC prompts the user to answer risk questions and resulting from answers given, will be required to enter control measures to reduce the risk. When the assessment is complete the user will upload the assessment and sign off the risk assessment. The actions generated during the assessment will be placed on an actions database and assigned to individuals with a time frame for completion. People who are assigned actions will be automatically given reminders by email as to status of the action. When the action is completed the action is approved by the Health and Safety Manager. Reports can then be created of actions completed, actions not completed and number of assessment completed on time etc. A complete guide to the system is detailed in Appendix 15.

1.7.4 2003 PHA Study

A review of the safety report took place at end 2003 and it was decided that the previously used methodology might not be sufficiently detailed to include all possible scenarios. Dynea Ireland, to comply with the requirements of SI 476 of 2000, requested that a Preliminary Hazard Analysis study (i.e. PHA) be conducted on their Marino Point facility to assist in the formal identification of the major hazard scenarios associated with their manufacturing and storage facility. Another outside consultant was engaged and a Preliminary Hazard Analysis was carried out with the involvement of key Dynea personnel. Preliminary Hazard Analysis is typically used to identify site major hazards and as a precursor to further detailed analysis of the hazards identified.

The technique of Preliminary Hazard Analysis2,3 is typically used to identify the major hazards associated with a production or storage facility and is a precursor to a more detailed analysis of major hazards using the technique of Quantified Risk Assessment.

A PHA study typically has the following steps:

2 Institution of Chemical Engineers, Hazard Identification and Risk Assessment, Geoff Wells, 1996 3 Loss Prevention in the Process Industries; 1996; Volume 1. @

Page 3 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safetv ReDort Dociment Revision: Issue Date: Number:1.0.3 3 111 2105

0 The plant is divided into study sections or nodes. 0 A PHA study team is assembled for the section or node under study. 0 Guide-words appropriate to PHA are applied to the section of plant under study to help

identify scenarios with major hazard potential.

The guidewords address major hazards such as:

0 Fire and explosion. 0 Chemical. 0 Environmental. 0 Thermodynamic (pressure and temperature) 0 Domino Effects.

For each major hazard scenario identified a Severity Ranking is assigned as follows.

Severity 5: Catastrophic Consequences 0

Severity 4: Severe Consequences Severity 3: Major Consequences Severity 2: Appreciable Consequences

Severity 1: Minor Consequences

A frequency at which it is judged that this scenario is likely to occur is assigned.

A priority rating for the scenario is assigned for further study using the risk ranking matrix as shown in Table 1.

Based on Table 1, a formal mechanism to allow the major hazard scenarios to be ranked and prioritised for further study is provided. The purpose of this prioritisation and selection process is to allow for a representative set of scenarios for further study to be compiled from the initial list of major hazard scenarios that has been generated by the PHA process. Many of the scenarios identified from a PHA study have similar severity ratings and similar consequences. Judgement is therefore applied to ensure that the set of scenarios selected for further study is representative of the cross range of major hazards presented by a facility. e

I Page 4 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number:l.O.3 3 1 I1 2/05

Risk Ranking Matrix

Risk = L+S

Lower Value of Lower Risk Equal Greater

\ L l -2

Severity (S) I -I I o I o

Risk = loglo loL + loglo I O s

= L + S

The Risk is only acceptable when its value is equal to or less than zero.

A

B

C

None

= High priority for further study (risk considered to be high)

= Further study probably required (risk considered to be medium)

= Further study may be unnecessary (risk considered to be low)

= No further study (risk considered to be well within acceptable limit)

Table 1 Risk ranking matrix

Dynea conducted the PHA exercise at Marino Point in late 2003, early 2004. A further review of the study took place in the third quarter of 2005.

Page 5 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: issue Date: 0 Number:1.0.3 3 111 2/05

Preliminary Work

An inventory of all materials stored, used or produced at Dynea was drawn up. All the substances covered by SI 476 of 2000 were identified, with the inventories and risk phrases assigned and storage locations identified. The inventory included by-products and intermediates, which are produced from planned and unplanned operations at Dynea. This process ensured that all dangerous substances under SI476 of 2000 and their influence on major accidents were considered in the assessment process. Within the Dynea group a HSE database is used to record all accident and near misses that have occurred in its plants worldwide. This information was gathered prior to the PHA study and used to aid the identification of Major accident scenarios. Information from past incidents at the plant at Dynea was also used. This information was recorded on the PHA pro forma.

7.7.5 PHA / HazOp Study Team Q -

The PHA team was selected on the basis of their experience and knowledge and expertise to ensure that all major accident scenarios were identified and each of the associated risks assessed. The team members have had appropriate training in hazard identification and risk assessment and have knowledge of all operations at the plant. The study team also included an outside consultant who facilitated the whole process.

The members of the team are as follows:

James O’Callaghan - Production Manager 21 years experience in the food and bulk chemical industry, primarily at a supervisory level. Previously employed by Wheat Industries/Cerestar in Ringaskiddy and FMC in Little Island. Completed City and Guilds 275 Instrumentation

Has worked for Dynea since before start-up in 1996, initially in a shift leader (production supervisor) role and since November 2000 as the Production Manager with overall responsibility for all manufacturing activities on site.

Dermot O’Callaghan - Laboratory Analyst/ HSE Chemist BSc. Industrial Chemistry from University of Limerick 1997. Has completed a Diploma in Safety Health and Welfare at Work in 2004. Has attended Risk Assessment courses provided by outside consultants through Dynea.

@

Has worked for Dynea since 1997 as a laboratory analyst with primary responsibility for air and water environmental sampling as well as all raw material and finished product testing. Has, since Q1 2003, assisted in HSE duties and, since Q1 2004 has been on full-time HSE duties.

Peter O’Regan - HSEITechnical Services Manager BSc Industrial Chemistry from the University of Limerick in 1991. MSC in Environmental Analytical Chemistry from UCC in 1993. HDip in Management and Marketing from UCC in 1998. Cert. in Health Safety and Welfare at Work from UCD in 2001.

Previously worked for SmithKline Beecham (now Glaxo SmithKline) in Dungarvan. First as a lab analyst, then as a LlMS (laboratory information management systems) co-ordinator responsible for creation and validation of new protocols and finally as technical services co-ordinator for packaginghableting - commissioning and validating equipment.

Has worked for Dynea (previously Dynochem) since start-up in 1997 - first as lab supervisor/environmental chemist; then as quality, safety and environmental manager/plant chemist; and since Q1 2003 as HSEiTech Services Manager. @

Page 6 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

I

duma Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: 9 Number:1.0.3 3 1/12/05

.J

Member of: The Institute of Chemistry of Ireland The Emergency Planning Society (Ireland Branch)

Denis Curtin -Consultant, MSc. (Eng.), M.I.E.I., M.I.Chem.E., M.I.0.S.H Denis Curtin is a qualified chemical engineer with a post-graduate degree in process safety. He has 18 years experience working within the pharmaceutical, fine chemical and gas processing industry, including employment as safety manager for a major hazard process, storage and distribution installation.

Over the past 7 years he has worked as a consultant to the pharmaceutical and chemical industry in process safety. He specialises in quantified risk assessment techniques for major hazard sites, and process safety management evaluation and development.

Denis Curtin graduated from the Cork Institute of Technology in 1986 with a Degree in Chemical Engineering and graduated with Distinction from the University of Sheffield in 1995 with a Master’s Engineering Degree in Process Safety and Loss Prevention. (D

Denis Curtin set up a consultancy practice in process safety to provide support and assistance to the chemical and allied industry in accident and incident prevention.

Member of: The Institution of Chemical Engineers. The Institution of Engineers of Ireland. The Institution of Occupational Safety and Health.

7.7.6 Areas Assessed

For the purposes of the risk assessment, the overall plant was broken down into areas. All areas of the site were assessed. Areas in which there was no likelihood of a dangerous substance being present were identified but were eliminated from the study.

The locations assessed include: 1. Methanol ship offloading at jetty 0 2. Pipelines 3. Methanol Tank T401 4. Methanol Road tanker loading/Offloading area 5. Formox process 6. By - products / Intermediates 7. Formalin Tanks (50% formaldehyde) 8. Reactors 9. Chemical Storage IO. LPG Storage 1 1. Diesel storage

I

The study covers all areas where dangerous substances are stored used or produced.

7.1.7 PHA Procedure

Maior Accident Scenarios The PHA team assessed each of the above areas in detail. The contracted consultant produced a PHA pro- forma which is detailed in Appendix 15. The process involved determining the Major 0

I Page 7 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

dynea Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date:

@ Number:1.0.3 3 1 I1 2/05

Accident Scenario (MAS) for each area. Each area was assessed and an assessment made of the consequences. Site Major Accident Scenarios (MAS) generally fall into the following categories:

Explosions Fires Toxic Gas Releases Environmental Impact

Assianina Severity Rating Each event was assigned a Severity Rating between 1 and 5 in accordance with PHA methodology, bv assessing the realistic potential consequence. Severity ratings are assigned on the basis of health a i d safetv and environmental impacts. For any incident which would incur significant costs, the severity rating may be increasedi.e. property damage, environmental cleanup etc. The tables used for assigning severity ratings are given in Table 2.

Q Severity Rating Consequences Consequence detail

5 Catastrophic

4

3

2

Severe

Major

Appreciable

1 Minor

Catastrophic damage and severe clean-up costs. On-site: Loss of normal occupancy > 3 months. Off-site: Loss of normal occupancy > 1 month. Severe national pressure to shutdown. Three or more fatalities of plant personnel. Fatality of member of the public or at least five injuries. Damage to historic building. Severe environmental damage involving permanent or long term damage to a significant Severe damage and major clean-up. Major effect on business with loss of occupancy up to 3months. Possible damage to public property. Single fatality or injuries to more than five plant personnel. One in ten chance of a public fatality. Short-term environmental damage over a significant area. Severe media reaction. Major damage and minor clean-up. Minor effect on business but no loss of building occupancy. Injuries to less than five plant personnel with one in ten chance of fatality. Some hospitalisation of public. Short term environmental damage to water, land, flora, or fauna. Considerable media reaction. Appreciable damage to plant. No effect on business. Reportable near miss incident under EC Directive - Seveso It. Injury to plant personnel. Minor annoyance to public. Near-miss incident with significant quantity released. Minor damage to plant. No effect on business. Possible injury to plant personnel. No effect on public, possible smell

Page 8 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

- dynea Dynea Ireland Limited Standard Operating Procedure

Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: 0 Number:1.0.3 3 111 2/05

Table 2 Major Accident Scenario Severity Ratings

The severity ratings used in the Dynea PHA study ensures that all notifiable incidents as defined under schedule 7 and 8 of S.1 476 of 2000 of the regulations are captured as shown in Table 3 .

SI 476 of 2000 Dynea Severity Ratings

Schedule 7 Any fire, explosion or accidental discharge involving at least 5% Of the qualifying quantity laid down in Annex 1 of the Seveso 11 Directive, i.e. -1 0 tonnes of Formalin -250 tonnes of Methanol - a death, - six persons injured within the establishment and hospitalized

- one person outside the establishment hospitalized for at least

- dwelling(s) outside the establishment damaged and unusable

- the evacuation or confinement of persons for more than 2

-the interruption of drinking water, electricity, gas or telephone

for at least 24 hours

24 hours,

as a result of the accident,

hours (persons x hours): the value is at least 500,

services for more than 2 hours (persons x hours): the value is at least 1 000.

e

permanent or long-term damage to terrestrial habitats: - 0,5 ha or more of a habitat of environmental or conservation

- 10 or more hectares of more widespread habitat, including

- significant or long-term damage to freshwater and marine

importance protected by legislation,

agricultural land,

habitats Significant or long term damage to terrestrial habitats

10 km or more of river or canal, 0 - 1 ha or more of a lake or pond, - 2 ha or more of delta, .- 2 ha or more of a coastline or open sea,

Significant damage to an aquifer or underground water >I ha Damage to property - damage to property in the establishment at least ECU 2 million, - damage to property outside the establishment; at least ECU 0,5 million - Cross- border damage Schedule 8

The explosion, collapse or bursting of any closed vessel, including a boiler or boiler tube, in which the internal pressure was above or below atmospheric pressure. An explosion or fire occurring in any installation or place which

Q)

2-5 2-5 4

4

4

4

2

2

4-5 4-5

4-5

5 3-4 3-4 3-4

4-5

4-5

4-5

Not applicable

3

Page 9 of 65 :'i

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: 0 Number:1.0.3 3 1/12/05

resulted in the stoppage of any part of the installation or suspension of normal work in that place for more than 24 hours, where such explosion or fire was due to the ignition of process materials, their by-products (including waste) or finished products. The uncontrolled or accidental release or the escape of any dangerous substance from any apparatus, equipment, pipe work, pipe-line, process plant, storage vessel, tank or in works conveyance tanker, which, having regard to the nature of the substance and the extent and location of the release or escape, might have been liable to cause serious injury to any person or serious damage to the environment.

3

2-3

Any unintentional ignition or explosion of explosives

containing a dangerous substance:- (a) the bursting, explosion or collapse of a pipe-line or any part thereof; (b) the unintentional ignition of anything in a pipe-line or of anything which immediately before it was ignited was in a pipeline.

Table 3 Notifiable incidents as defined under schedule 7 and 8 of S.1476 of 2000

Not applicable

Depending on severity of pipeline damage

Either of the following incidents in relation to a pipe-line 1-5

@

Identification of initiafinq events After assigning the severity rating the team completes the PHA pro forma. A structured approach was used by the PHA facilitator to identify the initiating events which could lead to a major accident. Which include mechanical failure, human error, control equipment failure, external events etc. This detail is recorded on the PHA pro forma as detailed in Appendix 15.

Assiuninn frequency rating A PHA will not give an accurate assessment of the frequency of any incident nor the measures used to control or avoid the release. With this technique it is particularly important to identify the worst accident which might occur such as the greatest fire, explosion, toxic gas release, or incident with a major environmental impact.

For a PHA study, it is also not necessary with this step of an analysis to determine exact frequencies -a

of events. The acceptable frequency ratings are detailed below foreach of the severity classes

Severity Description Acceptable frequency(occurrence per year) 5 Catastrophic 10-5 4 Major 10-4 3 Severe 10-3 2 Appreciable 10-2 1 Minor 10-1

Identifying all the site major hazards is, however, essential, as a hazard omitted is a hazard not analyzed. The frequency ratings were assigned using the following information available.

The methodology involved in conducting a PHA study is detailed in Appendix 15.

Page 10 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

- dynes Dynea Ireland Limited Standard Operating Procedure

Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number:l.O.3 3 1/12/05 e With the assistance of the risk-ranking matrix outlined in Table 1 above, Table 8 summarises the major hazard scenarios that are representative of the Dynea Ireland site, and where further detailed analysis is required.

Physical Inspections Physical inspections were carried out at the site to ensure that measures discussed at the PHA meeting were in fact present and to identify other existing measures that should be accounted for.

1.1.7.1 After the PHA study was completed a study group was formed to examine the hazard scenarios and to assess the adequacy of the control measures in place. The criteria used to determine the adequacy of the risk control measures is based the ALARP (As Low As Reasonably Practicable) principle. The assessment involved assessing the control measures for each Major Accident Scenario and determining whether the control measures reduce the risk to an acceptable level (as low as reasonably practicable). Control measures which did not satisfy the ALARP criteria were subject to further analysis. A standard pro forma was developed, this pro forma and the detail of assessments is detailed in Appendix 15. The team carrying out this assessment was made up of HSE Technical Services Manager and Production Manager, Quality Manager and Health and Safety Officer. These discussions involved assessing all accidents regardless of severity. Accidents with severity 3, 4 or 5 were categorised as major accident scenarios. Incidents with low severity but high frequency were assessed to determine whether by virtue of their high frequency, they would be classified as major accident scenarios.

PHA Assessment of Major Accident Scenarios

,@

1.1.8 Consequence Modelling

1.1.8.1 Quantified Risk Analysis In a QRA both the frequencies of events and their consequences are quantified, using appropriate techniques. Typically, QRA will consist of the following steps:

1. Identification of the hazards. 2.

3. 4.

Summarising the findings of the hazard identification study as a set of scenarios to be modelled. Estimation of the rates and duration of releases, and the quantities of material involved. Estimation of the consequences of each release in terms of an area inside which, for a given wind speed /weather stability combination, a specified level of harm (toxic load, explosion overpressure, thermal radiation flux) will be met or exceeded. Consideration of the effects of mitigation (for instance by people going or staying indoors). Translation of the release, by way of a model of human impact, into a measure of harm (e.g. injury or fatality) to the specified individual or population. Estimation of the frequencies with which events (usually releases of hazardous material from their containment) are expected to occur. Combination of various probabilities and frequencies to calculate numerical estimates of risk.

a 5. 6.

7.

8.

Steps 1 to 3 results in a set of scenarios for modelling, together with the necessary data to compute frequencies and consequences. It should be conducted by an experienced analyst or team of analysts. Step 4, on the other hand, usually involves some form of modelling of gas dispersion, fire or explosion effects. This is carried out by use of computerised models which will be discussed in the next section. It is possible to produce different types of numerical risk estimate at step 8, depending on the purpose of the QRA study. Broadly speaking, numerical risk estimates are one or both of:

- Individual risk estimates; and Societal (or group) risk estimates. Q -

Page 11 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: N um ber: 1.0.3 3 1/12/05

dynea

Individual risk has been defined as follows (HSE 1995): “Individual risk is the risk of some speciJied event or agent harming a statistical (or hypothetical) person assumed to have representative characteristics. ’ I

The ‘individual’ referred to will be defined in accordance with the requirements of the QRA to be undertaken. It may, for example, be a member of a certain group of workers on a facility with defined characteristics in terms of their working pattern. Alternatively, the individual may be defined so as to be representative of a member of the public, such as the ‘hypothetical house resident‘ .The ‘specified event or agent‘ may be defined as fatality, injury, or exposure to a defined level of blast overpressure, thermal radiation or dose of toxic material.

Quantitative risk assessment (QRA) involves obtaining a numerical estimate of the risk from a quantitative consideration of event probabilities and consequences.

@ 1.1.8.2 Modelling

The objective of consequence modelling is to predict the impacts of accident scenarios involving fires, explosions and toxic release on the site. The quantitative data resulting from the consequence modelling was used as an aid for assigning severity rating in the PHA study, for the development of the specified area around the Dynea site and as an aid in emergency planning.

The consequences of the scenarios were modelled using the DNV Technica computer packages PHASTMicro and WHAZAN, and the US EPA-approved air dispersion model lSCST3.

PHAST examines the progress of a chemical process incident from initial release through formation of a cloud or pool to final dispersion - calculating concentration, fire radiation, toxicity and explosion overpressure. Due to its reliability and outstanding technical superiority, PHAST is used by over 300 organisations world-wide.

PHAST is a comprehensive hazard analysis package, applicable to all stages of design and operation across a range of process and chemical industry sectors. It is used to identify situations which present potential hazards to life, property or the environment. Such scenarios may be removed by re-design of the process or plant, or modification to existing operational procedures. Scenarios which remain may be submitted to further analysis such as rigorous risk assessment, where necessary, using more sophisticated QRA tools such as SAFETI.

The Unified Dispersion Model (UDM) used in PHAST has been extensively verified and has been validated against a large number of field experiments. These include continuous, elevated two phase and vapour releases, ground level liquid spills and unpressurised instantaneous releases. A subset of these experiments were used in the EC funded SMEDIS project. The SMEDIS project is an independent review of both the theory and the performance of many dispersion models. The UDM has excelled in both aspects of the review

The Industrial Source Complex Short Term (ISCST3) model is the US Pea’s current regulatory model for many New Source Review (NSR) and other air permitting applications. The ISCST3 model is based on a steady-state Gaussian plume algorithm, and is applicable for estimating ambient impacts from point, area, and volume sources out to a distance of about 50 kilometres. ISCST3 includes algorithms for addressing building downwash influences, dry and wet deposition algorithms, and also incorporates the complex terrain screening algorithms from the COMPLEX1 model.

Extensive in-house modelling was carried out on ALOHA - the dispersion modelling software developed jointly by the US Environmental Protection Agency (EPA) and US National Oceanic and Atmospheric Administration (NOAA). ALOHA has a number of limitations which are mentioned below. @

Page 12 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

dynea Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date:

@ Number:l.O.3 3 111 2105

Condition Pasquill Atmospheric Stability Category

PHASTMicro is a package consisting of a series of linked models that predict the consequences of releases of hazardous materials, whether flammable, toxic or both. WHAZAN is an older and simpler package consisting of a series of stand-alone models that perform essentially the same function as PHASTMicro.

Wind Speed (mW

ISCST3 is a suite of models that are used to predict the ambient air quality from industrial source complex terms. A previous version of the model was used to predict the impact of normal or licensed emissions from the plant. The model was used to predict abnormal emissions for this study.

Extensive in-house modelling was carried out on ALOHA - the dispersion modelling software developed jointly by the US Environmental Protection Agency (EPA) and US National Oceanic and Atmospheric Administration (NOAA). ALOHA has a number of limitations which are mentioned below.

ALOHA'S results can be unreliable when the following conditions exist:

(a) Very low wind speeds e (b) Very stable atmospheric conditions (c) Wind shifts and terrain steering effects (d) Concentration patchiness, particularly near the source

ALOHA doesn't account for the effects of:

(a) Fires or chemical reactions (b) Particulates (c) Solutions and mixtures (d) Terrain - ALOHA expects the ground below a leaking tank or puddle to be flat, so that the liquid spreads out evenly in all directions. It does not account for pooling within depressions or the flow of liquid across sloping ground. The raw data required for the modelling is detailed below.

Material Properties

The model was used with the standard properties of methanol and formaldehyde. For modelling of formalin, a new material was defined as a 50% aqueous solution of formaldehyde. The vapour pressure of formaldehyde over an aqueous solution of this strength at various temperatures was taken from published material, and a correlation fitted to the data. The correlation was inserted into the data file. Other physical properties of 50% aqueous were also inserted into the data file.

s)

Meteorological Conditions

Two standard meteorological conditions were used and these meteorological conditions are representative of the majority of the conditions experienced at Cork Airport.

~ Page 13 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report

3

dynea

D 5

- Document Revision: Issue Date: Number:l.0.3 3 1 I1 2/05

Concentration Limits .

For methanol and formaldehyde, the model was used to predict the dispersion distances to the various concentration limits, i.e. ERPGI, ERPG2, ERPG3. An explanation of these terms is detailed in Table 5.

Q

ERPG

ERPG- 1

ERPG-2

Basis

Effects other than mild transient adverse health effects or perception of a clearly defined objectionable odour

Irreversible or other serious health effects or symptoms that could impair an individual's ability to take protective action.

Life threatening health effects

Table 5 Toxic Harm Criteria

The ultimate concentration of interest for formaldehyde was specified as 10 ppm (ERPG-2). The ultimate concentration of interest for methanol was specified as 250 ppm (OEL-STEL).

These concentration limits is a time-weighted average, and are based on specified time periods. The model calculates the dispersion distances for time-averaged concentrations. As the time over which the concentration is averaged increases, the average concentration for that time decreases.

' I Page 14 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

I

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safetv ReDort

- Dociment Revision: Issue Date: @ Number:1.0.3 3 1/12/05

7.7.9 All Necessary Measures

Dynea is committed to putting in place all necessary measures to prevent major accidents occurring at the plant and to limit the consequences of any such major accidents to man and the environment. During the PHA process and the HazOp study, the systems in place at Dynea are assessed to ensure that the risk to man and the environment is as low as is reasonably practicable (ALARP). If the systems in place are not adequate an analysis will be carried out to determine the necessary measures required to reduce the risk to as low as reasonably practicable.

The assessment was carried out as set out below.

Staae 1 - PHA Team Meetinas During the PHA study, each scenario was described and assigned a risk rating based on the likelihood of occurrence and severity of impact. The relevant risk reduction and consequence mitigation measures in place for each scenario were recorded by the PHA team. Additional measures highlighted during the study were included in an implementation programme. These measures will further reduce the risk of major accident scenarios.

Staqe 2- Review of PHA findinqs. After the scenarios were identified a process began whereby a review of the PHA findings was undertaken. This involved determining appropriate actions to reduce higher levels of risk to as low as is reasonably practicable. Actions generated during the study were assigned to individuals to complete. These actions are tracked by the HSE Technical Services Manager. Actions that are not closed out are tracked at the HSE monthly meetings and further resources will be made available to close these actions out.

7.7.70 Review

The hazard identification process will be reviewed every 5 years as part of the Safety Report review which is required under SI476 of 2000. The process will also be carried out once there has been a significant increase in inventory of Seveso 2 substances at the Dynea facility, and where installation of new plant and equipment is taking place at the site. This review will be triggered by the control of change procedure.

The review process will ensure that the hazard identification processes reflects all changes in installed plant, operational procedures etc. and will ensure maximum protection for both man and the environment at all times.

ab 1

Page 15 of 65 i

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10


1.2 Major Accident Hazards Excluded

1.2.1.1 Aircraft Impact In a recent report the Department of Transport and the Department of the Environment and Local Government commissioned ERM (Environmental Resource Management) consultants to carry out an investigation of the Public Safety Zones (PSZs) at lrelands 3 principle airports Dublin, Shannon and Cork. The purpose of the report was to prevent inappropriate use of land during the planning process, where the risk from aircraft crashes in a populated area is the greatest. This study involved using risk modelling techniques to quantify the risks to the public from aircraft crashes. The proposed PSZ for Cork Airport is shown in Figure 1.

Figure 1 Public Safety Zones (Source ERM Ireland)

The areas of highest risk of airplane crashes are in the vicinity of the airport due to the amount of air traffic in the area. This area is highlighted in yellow on the map. The area outside the outer zone shows that the individual risk from an aircraft crashing is (UK HSE6 guidance proposes an individual risk of death of per annum as the threshold between the broadly acceptable and tolerable risk to the general public.) Any location in this area will not be restricted from development

5 Public Safety Zones: Cork, Dublin and Shannon Airports, ERM, June 2003(Draft) on behalf of Department of Transport and Department of Environment & local Government. 6 Reducing Risks, Protecting People: HSE’s decision- making process. Health and safety Executive, 2001

Page 16 of 65

@

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: issue Date: N um ber: 1.0.3 3 1/12/05

I

dynea

on the basis of the Public Safety Zones. The plant at Dynea is well outside these zones in Cobh and based on this probability, an aircraft crash is not likely to result in a Major Accident Scenario

1.2.1.2 Earthquakes The School of Cosmic Physics (part of the Dublin Institute of Advanced Studies) has been monitoring earthquake activity in Ireland since 1978. They have concluded that Ireland is seismically very stable and that this is unlikely to change in the future. The US geological Survey (have recorded the number of earthquakes across Europe between 1975 and 1995.

Figure 2 Earthquake Incidents in Europe

From the diagram in Figure 27, it can be seen that there was scarcely any earthquakes in Ireland in that period. Any recorded activity in Ireland was confined to the Southeast and Northwest of the country. There are no figures on the map to quantify the risk; the map does show that there were

7 US Geological Survey Page 17 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date:

Maximum Daily Value Maximum Hourly Value Maximum Monthlv Value

dynea

85mm/day 23.7mm/hr 220.5mm/month

- - -. . . -. . .

Number:1.0.3 3 1/12/05

scarcely any earthquakes in Ireland during the period from 1975 to 1995. Based on this information a Major Accident resulting from an earthquake at Dynea was eliminated from the study.

1.2.1.3 Floods Rise in Sea Level Flooding from estuaries or the sea is generated from sea levels (a combination of astronomical tides, atmospheric surges, wind set-up and waves) exceeding the level of, and hence spilling onto, the neighbouring land.

The tidal levels at Ringaskiddy are given in Table 6.

Table 6 Tidal Levels at Ringaskiddy Table 6 Tidal Levels at Ringaskiddy

The average mean sea levels in Southwest Ireland are rising at a rate of 1 mm per annum'.

The maximum height recorded at Ringaskiddy is 4.3m. The harbour is at its widest point at the Dynea site, which means that it can retain a substantial amount of water before an increase in water height would be noticed. The plant at Marino point has no history of flooding. The Dynea site is approximately 6 m above the datum line. From historical data recorded at the Jetty and from an examination of the records at Port of Cork shows that since 1980 the highest tide(inc1uding waves) has been 5.2 m with 5.0m being reached three times. From this data we can conclude that the probability of flooding at the Dynea site is very low and is thus not considered as a major accident scenario.

Storm water All storm water at the site flows into the main collection point at Basin 1. Bunded areas at the site are closed systems and storm water will collect there. This storm water is drained to Basin 1 by opening valves at the bunds. After heavy rainfall operators check the bunds and drain the water to Basin 1.

In order that a tank would float the water level in the bund would have to rise to a sufficient level. This is unlikely to happen in the resin tank farm as the bund wall is only half a meter. The rainfall recorded at Roche's Point is given in Table 7. @

I I Rainfall I

Table 7 Average and Worst Case Rainfall

In order to float the methanol tank (empty) a water depth of approximately 2 meters in the bund would be required. This would mean that it would need to rain for approximately 9 months at the maximum monthly value to float the tank (this would mean that the bund would never have been emptied of rainwater for those 9 months). Based on the above information, a major accident involving storm water flooding at the plant has been eliminated on the grounds that the probability is too low.

1.2.1.4 Subsidence The Dynea site is a partly reclaimed site located at Marino Point. A full Geotechnical Survey including

@ 8 OPW Publication "Report of the Flood Policy Review Group " 9 ENFO publication BS27, ' Sea Level Changes and Ireland'.

Page 18 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:10

a Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number:l.O.3 3 111 2/05

I

dynea

boreholes and trial holes was carried out in 1995. The most Northerly end of the site is recently reclaimed, with levels raised by importing stone prior to construction of the new plant. All the main structures on the north end of the site are piled, these are:

0 Urea Store 0 Resin Building

Formalin Building Control Building

0 The Former Spray Dryer The Former Packaging Building

In addition, because of the very high loading, the concrete slab directly beneath the Methanol Tank is piled. The remainder of the Methanol bund is not piled, due to its large surface area. The Waste Water Treatment Plant contract was originally let as a design and build contract to EPS, with specific mention that the foundations were to be piled. During the end of 2003 it was noticed that the aeration tank were subsiding. In 2004 engineers were contracted to carry out an assessment of the tanks in the waster water treatment plant. As a result of this assessment the tank was dismantled and piling began in the summer of 2005. The tank has been reassembled and at time of writing and is undergoing leak tests.

The resin tank farm is not piled but is instead designed as a raft slab. The overall loading on the slab relative to the area of the slab is not excessive. Also the location of the tank farm is away from the Northern end of the site, where the very poor ground conditions are located. Based on the above information, a major accident resulting from subsidence at the plant has been eliminated on the grounds that the probability is too low.

I .3 Major Accident Scenarios

The list of major accident scenarios compiled during the PHA study is detailed in Appendix 15. From this list a subset was identified as detailed in Table 8. A number of follow up action items were raised during the PHA study meetings where further information or investigation is required to ensure that the severity of the scenario assigned is correct and clearly understood. Actions generated during the study were assigned to individuals to complete. These actions are tracked by the HSE Technical Services Manager. Actions that are tracked at the HSE monthly meetings and further resources will be made available to close these actions out. On-going reviews of these action items will be conducted by Dynea Ireland until all of these issues have been addressed. The HSE manager is responsible for ensuring that actions generated for reducing the likelihood of major accidents are closed out. The findings of the PHA major hazard scenarios identified through the PHA study are detailed in Appendix 15. The scenarios are ranked according to the degree of severity (and priority for further analysis) as assigned by the PHA study group and in accordance with the criteria set out for conducting Preliminary Hazard Analysis.

63 scenarios were identified and assessed for the site, broken down as follows:

0 Five scenarios were ranked as potentially having catastrophic consequences i.e. Severity 5.

0 One scenario was ranked as severe i.e. Severity 4.

0 Thirteen scenarios were ranked as major i.e. Severity 3.

0 The remaining scenarios were ranked as having appreciable consequences i.e. Severity 2 or lower.

Page 19 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: 6 Number:1.0.3 3 1 / I 2/05

The potential consequences of the scenarios identified are various e.g. thermal radiation effects from a Methanol fire, overpressure effects from a reactor explosion, toxic vapour exposure from a Formaldehyde release, and environmental impacts to the harbour from a Methanol spill.

With the assistance of a risk ranking matrix as outlined in Table 1, a total of 15 scenarios are selected as representative of the major hazard scenarios associated with the Dynea Ireland site. The Scenarios are listed in Table 8 below.

Page 20 of 65 j

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: @ Number:1.0.3 3 1/12/05

0

- No. 01

- 07

- 10

Severity 5

5

5

Priority A

A

A

Scenario Description Ship off loading methanol - loading arm leaks or fractures - solvent ignites resulting in a large scale fire on the jetty potentially engulfing the ship and resulting in a large scale explosion on the ship. Methanol storage tank TK401 fails instantaneously - resulting in a large release of Methanol which overtops the bund wall - and ignites encompassing a large area.

Similar to Scenario 06 - solvent fire in bund - a prolonged fire causes the tank to overheat and rupture resulting in an overpressure effect locally.

Potential escalation of Scenario 10 -where a rupture of the storage tank potentially impacts on the Methanol road tanker loading/offloading bay and other production/storage areas.

Methanol road tanker rupture/explosion.

Flammable air/Methanol mixture within a reactor - mixture ignites - potential overpressure and rupture of reactor causing a blast effect.

Similar to Scenario 07 no ignition occurs - dispersion of toxic vapours over local area.

Similar to Scenario 01 -the ship off loading arm leaks or fractures - resulting in a spill of solvent causing a local environmental impact on the harbour area.

Similar to Scenario 01 -where a Methanol pipeline leak/fracture xcurs on the line leading to the storage tank - causing local :ontamination of the soil.

Methanol storage tank TK401 - eak into the bund - solvent gnites - potential radiation 2ffects from a large scale fire.

Hazard Effects Thermal radiation effects

Explosion overpressure effects

~~

Thermal Radiation

Overpressure/blast effect


Ove rp ressu re/b last effect


Toxic effects

Environmental Impact

Environmental Impact

Thermal radiation effects

Page 21 of 65 I

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

B


Similar to Scenario 07 no ignition occurs - potential environmental impact of a spill on the local

Environmental impact

- No.

09

- -

B

B

24

- 29

- 53

- 61, 62

- 'able

Formaldehyde vapours - potential impact on personnel.

Formalin Tank instantaneous Toxic effects rupture - Formaldehyde toxic gas vapours disperse and potential impact on personnel.

WWTP tank rupture due to subsidence causes a short term environmental impact.


Severity

C

3

Fire water retention pond leaks or overfills - potential environmental impact.


3

3

Priority I Scenario Description I Hazard Effects I I

1 harbour area: B I Formox Process - leak of 1 Toxic effects

b: Summary of Dynea Ireland site Major Hazard Scenarios

The PHA did not identify any significant new hazards which required modelling so the originally identified set was used for this purpose. The following major accident scenarios were identified in the original Major Accident Scenario assessment for the Dynea site:

Fire Methanol Tank Fire

0 Methanol Bund Fire

Formalin Plant Fire Ignition of methanol

0 Ignition of Dowtherm 0 Ignition of Stabilizer 0 Methanol Ship Fire

Methanol Tanker Loading Bay Fire

Q) 0 Ignition of formaldehyde

Explosions Reactor Head Space Explosion

0 Methanol Tank Explosion Gas Explosion

t

Loss of Containment 0 Formaldehyde Gas Cloud Release 0 Formalin Tank Rupture 0 Formox Process Rupture 0 Methanol Release

Methanol Tank Rupture 0 Methanol Ship Spillage to water

Page 22 of 65 I

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11


Radiant Heat ( kW/m2)

dynea

Effect

0 Methanol Tanker Loading Spill

Domino Effects 0 Domino Effects IF1

Transport of Hazardous Materials (Road Transport Regulations) 0 Methanol 0 Formalin

Major-Accident Scenarios with Environmental Impact

Major-accident scenarios with environmental impact comprise all of the above. In particular, the following accidents are considered:

Loss of containment of methanol - pollution of Cork Harbour may affect aquatic flora and fauna Loss of containment of formaldehyde - pollution of Cork Harbour and air pollution may affect flora and land-based fauna Fire involving methanol, resin or formaldehyde - products of combustion may affect flora and land-based fauna

0

0

0

@

1.3.1 Fires

Three thermal radiation levels are chosen to cover a range of effects of fire:

4 I Not fatal, but will prevent escape I 12.5 I Can be fatal I 37.5 I Can cause damage to equipment I

Table 9: Effects of Fire (Thermal radiation)

1.3.1.1 Methanol Tank Fire Methanol is stored in a bunded bulk tank. The tank diameter is 20 m and the capacity 3,805, tonnes. It is assumed that the quantity of methanol contained in the tank is 3,600 tonnes, i.e. 3.6 x 10 kg.

In this scenario, both the fixed and floating roofs of the methanol storage tank collapse. This could be caused by an external event or by mechanical failure. Catastrophic tank failure will result in the complete loss of contents of the tank to the bund. The HSEIO have carried out studies to show that a failure frequency of 2 x IO-’ per tank per year for large thin walled, non-pressurized tanks used for liquid storage. The actual failure frequency is a lot less than the figure quoted by the HSE as this calculated figure does not account for recent development in tank maintenance and inspection procedures.

Following collapse of the roof of the tank, the contents of the tank (methanol) vapourise and disperse with the wind.

10 Bund overtopping- the consequences following catastrophic failure of large volume Liquid storage vessels, A. Wilkinson, SRD/ HSE R530

I 1 Page 23 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number:1.0.3 3 1/12/05

Page 24 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11


Weather Conditions

” Document Revision: Issue Date:

Vaporisation Rate kgls

Number:1.0.3 3 1 I1 2/05

F2

D5

Fire ’ If the vapours catch fire almost immediately (“early ignition”), the flame burns back to the tank and the methanol burns as a pool fire, the diameter being the diameter of the tank. The hazard is thermal radiation on the surroundings. The flames tilt with the wind.

0.3

0.45

It is assumed that 3,600 tonnes are available to burn.

Radiant Heat (kWlm*)

The rate of vaporisation of methanol depends primarily on the wind speed. The predicted initial vaporisation rates are:

Distance from source centre (m)

F2 D5

4

12.5

37.5

54 47

35 33

23 25

q) Flash Fire The furthest extent of a flash fire was calculated to be:

Table 12: Furthest Extent of a Flash Fire from Methanol

Page 25 of 65 i

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: %, Number:i.0.3 3 1/12/05

1.3.1.1.1 Human Consequences The human consequences resulting from a methanol tank fire were determined using data readily available that illustrates the human effects of been exposed to heat energy. From the harm criteria data detailed in Appendix 15 it estimates that there would be a 1 % fatality level after 30 seconds at 35m from the source. This area would include all of the methanol bund and it would reach outside the bund wall. There is restricted access to the methanol bund at all times and the frequency of entry to the area is very low. The effects of the fire would reach the loading bay. In the vicinity of the loading bay there is 1 person with the load while it is loading. The loading procedure lasts for approximately 30 minutes and the operator would be in the area approximately 10 times in any one week. The bund wall would offer some shelter from the fire, giving the person in the methanol loading area time to leave the area.

The Canvey Report

0

0

assumes the following times to take cover from thermal radiation.

20 seconds for person outdoors to take cover from heat flux in the range of 6.5-12.6kW/m2. Less than 1 minute for a person outdoors to take cover from heat flux in the range 4-6.5kw/m2 @

People located in regions outside this zone will have varying degrees of burns during a methanol tank pool fire. The three types of burns are as follows.

0

0

0

Superficial Burn: This burn involves only the outermost layer of skin. Superficial burns are characterized by redness swelling and tenderness Partial- thickness burn: This affects the epidermis, and the skin becomes red and raw. Blisters form over the skin due to fluid released from the damaged tissues. Full-thickness Burn. With this type of burn, all the layers of the skin are affected; there may be some damage to nerves, fat tissue, muscles, and blood vessels.

The vast majority of employees are indoors in the administration building each day, which is approximately 100m from the source of the fire. Incident heat flux in the administration building would be less than 4kW/m2.

1.3.1.1.2 Environmental Consequences The majority of the methanol will be contained within the bund wall with minimal overtopping. During the fire, foam units will be turned on and this will reduce the heat effects from the fire. There will be minimal amounts of smoke as methanol is a low molecular mass molecule with only one carbon constituent. When the fire has been controlled there will be methanol/ foam mixture to be adequately dealt with. Since the foam will float on top of the methanol, the uncontaminated methanol underneath can be used in the process. The contaminated portion left will be sent away for incineration. At present there are studies taking place at Dynea to determine the feasibility of solvent recovery at the plant at Cork. This study is at the early stages but if it is implemented this would provide a safe way to recover the methanol. The effects of environmental impact resulting from bund failure are discussed in the loss of containment section of the report.

@

1.3.1.1.3 Risk Reduction Measures The original layout of the plant was designed such that the methanol storage facility had adequate separation form other areas at the site to minimise the spread of fire to other process areas and plant buildings. There are no permanent ignition sources in the vicinity of the tanks. The tanks including the methanol tank at the site were built in accordance with specific standards (see section 4). Non destructive testing is carried out on the methanol tank every 5 years. The maintenance policy as discussed in following sections of the safety report sets out the way in which Dynea Ireland preserve

0 11 Canvey, A Second Report. A review of potential hazards from operations in the Canvey Island/ Thurrock area three years after publication of the Canvey Report, HSE 1981.

Page 26 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: @ Number:1.0.3 3 111 2105

the integrity of plant and equipment to specific standards such that there will be no loss of containment or mechanical failures leading to major accident scenarios. It is planned that methanol vapour and flame detection system will be put in place at the methanol tank bund. At time of writing of this report Argos fire have visited site and are presently preparing a proposal to implement this initiative. This project is due for completion in the third quarter of 2006.

1.3.1.1.4 Mitigation Measures The mitigation measures for reducing the effects of a major fire are outlined in section 5 of the report (Emergency Response). The above scenario would involve opening valves to the foam unit by the cooling towers. The foam unit contains 10001trs of foam which is checked monthly to ensure availability. When operational it will feed the foam pourers in the methanol bund. This will have the effect of cooling the fire, and reducing the supply of oxygen to the flame and reducing vapour pressure. During normal office hours there are more people available to carry out site tasks during an emergency. The above operation would involve 2 trained personnel, ‘with full PPE opening the valves on the foam tank (if it is safe to do). This operation will take approximately 20 minutes. Outside normal office hours there will only be three personnel available. The shift leader in this case will take responsibility until Emergency Crew Leader arrives on site. The people resources at his disposal will be limited. He will contact the fire brigade and other competent authorities and interested parties and will then survey the situation. If it is safe to send two operators over to the foam tank to turn it on he will do that, if it is safe to do so.

@

1.3.1.2 Methanol Tank Bund Fire In this scenario, the contents of the methanol storage tank are lost to the bund. This could be caused by an external event or by mechanical failure. The contents of the tank (methanol) vaporise and disperse with the wind.

The bund floor area, net of the cross-sectional area of the tank, is 1,591 m2. The diameter of a circle of this area is 45.01 m. This scenario envisages a loss of containment of the bulk tank, so that the entire bund is flooded. This could be caused by a tank rupture, pipe rupture, pump leak, etc.

Page 27 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number:1.0.3 3 1 I1 2/05

.-

Radiant Heat ( kWlm2)

Pool Fire The thermal radiation levels from a pool fire were calculated to be as follows:


F2 D5

4

12.5

37.5

104 96

67 66

43 49

Distance from source centre (m) dl I 42 I 56 I Table 14: Furthest Extent of a Flash Fire from Methanol Bund

1.3. I. 2.1 Human Consequences The worst case scenario would be a pool fire, which would extend 66m under D5 weather conditions. This fire would extend to the car park and would cover the area of the methanol loading area. From the data outlined on Appendix 15, there would be a 1 % fatality level at 67m from the source after 30 seconds. There is restricted access to the methanol bund at all times and the frequency of entry to the area is very low. In the vicinity of the loading bay there is 1 person with the load while it is loading as discussed previously. The bund wall would offer some shelter from the fire, giving the person in the methanol loading area time to leave the area. At present the car park is situated in front of Basin 1. The majority of employees work in the administration building each day. Incident heat flux in the administration building would be less than 4kW/m2 and is not expected to present a major hazard.

e

1.3.1.2.2 Environmental Consequences As in section 1.3.1.1.2

1.3.1.2.3 Risk Reduction Measures As in section 1.3.1.1.3. As part of the budget in 2006 the car parking area will be moved to the eastern side of the plant, well away from the dangerous substance storage facilities.

I. 3.1.2.4 Mitigation Measures As in section 1.3.1.1.4

1.3.1.3 Methanol Tanker Loading Bay Fire 0

In this scenario, the contents of a road tanker (19.2 tonnes) are lost to the bund. This could be caused by rupture of a hose or pipe joint. Methanol would spill into the contained area and drain to the underground sump from which it is automatically pumped to the methanol tank bund. It is assumed @

\ I (

Page 28 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: 0 Number:1.0.3 3 1 /I 2/05

that the contained area is 200 m2. The diameter of a circle of this area is 15.96m. The contents of the tank (methanol) vapourise and disperse with the wind.

Pool Fire The thermal radiation levels were calculated to be as follows:

I 12.5 I 25 I 24 I I 37.5 I 17 I 18 I Table 15: Thermal Radiation Levels from Pool Fire in Methanol Tanker Loading Area

Flash Fire The furthest extent of a flash fire was calculated to be:

Table 16: Furthest Extent of a Flash Fire in Methanol Tanker Loading Area

1.3.1.3. I Human Consequences The worst case scenario would be a fire, which would extend 24m under D5 weather conditions. There would be a 1% fatality level at 24m from the source after 30 seconds. This fire would extend inside the methanol tank bund wall. In the vicinity of the loading bay there is 1 person with the load while it is loading. This person would be within 25m of the loading bay. The loading procedure lasts for approximately 30 minutes and the operator would be in the area approximately 10 times in any one week. This equates to approximately 3% of the working week that this person will be in the vicinity of the loading bay.

0

, ' I j i Page 29 of 65 I ~

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11

I

I. 3.1.3.2 Environmental Measures The environmental consequences of a methanol loading bay fire would be minor, as the volumes that are involved are relatively small. The bund will contain the majority of the load, however there will be overtopping. This overtopping will result in methanol spilling on to the gravel area by the methanol loading area bund wall. This methanol will seep into the soil (The degradation processes etc. of methanol in soil/ water is discussed in section 1.3.5). There will be foam pumped on the fire from 3 monitors in the loading bay area. When the fire is quenched this foam/methanol mix will be placed in ex rated IBC's and disposed of as per the regulations.

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: 9 Number:1.0.3 3 1 I1 2/05

1.3.1.3.3 Risk control measures The loading bay is positioned away from areas of high employee density. All plant personnel involved in loading and unloading methanol have been trained to do so. All the operators have many years' experience. During the loading process the operator remains with the load while loading/ unloading takes place. All tankers on site are inspected by DGSA (Dangerous Goods Safety Advisor) to ensure they are suitable for the purpose. Certification for tankers must be provided from haulier prior to loading. There is a tanker earthing system in place, which means that pumps will not start if a correct earthing connection is not made. A green light is shown on the display when a correct earth connection has been made. This eliminates the effects of static electricity. The pipe coupling to the tanker is a "Dry Link" coupling, which ensures liquid tight connection between hose and road tanker connection. The hose is armoured, thus preventing accidental damage. Footwear of people in the area is checked regularly to ensure that they are not capable of carrying any charge.

There is signage on entry into the loading area that all sources of ignition (mobile phones etc.) are prohibited in the area. The only source of ignition within the methanol-loading bay is the truck unit itself. All trucks must be certified for carrying flammable materials and must provide this evidence. All truck drivers receive site induction training and must provide evidence that they are Haz Chem. trained prior to distributing loads of methanol to customers.

1.3.1.3.4 Mitigation Measures Dynea have invested in a Deluge system at the methanol loading area. At present it is a manual system whereby one person can go over to the fire water valve, opens it from a safe distance. This will spray the whole loading bay with foam/water. This process takes approximately 20mins. If resources allow there are mobile foam monitors which can be used at a safe distance.

1.3.1.4 Methanol Ship Line Fire

(A fire in the ship carrying methanol is outside the scope of the site, and is therefore not included in this assessment.)

In this scenario, the pipeline carrying methanol from the ship to the bulk tank is ruptured, and pours on to the ground. In this analysis, it was assumed that the rupture takes place approximately half way between the jetty and the methanol tank, i.e. on the IF1 site. Over most of its route, the methanol pipeline is out of reach of vehicle impact - being behind buildings or on high pipe racks. In the areas where it is most exposed it is one of the middle pipes on the rack with outer pipes protecting it. On the most exposed side there are two major pipelines outside it, one of these being the fire ring main - a major impact on this side would, therefore, also take out the ring main and very large quantities of water would pour onto the spillage, lowering the vapour pressure and all but negating the likelihood of ignition. On the other side there is a narrow roadway beside the pipeline which would not reasonably allow a vehicle to turn into the pipe rack with the impact necessary to go through the outer pipe and into the methanol line.

The assumed pumping rate is 350 m3/hr, i.e. 280 tonneslhr or 77.8 kg/s. It is assumed that this continues indefinitely. The model does not allow for leaks of limited duration. It is however expected that the leak would be detected and the pump stopped within 20 minutes based on differentials between the ship and tank volumes. 20 minute isolation time is based on site personnel having to

Page 30 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11


Radiant Heat (kW/m2)

advise ships captain to stop pumps and that Dynea personnel to close valves at the methanol tank and from plant experience this time is very conservative.

The liquid methanol continues to spread around the source of the leak until the rate of vaporisation equals the rate of leakage. That is a steady-state condition. There is no containment.

The contents of the tank (methanol) vaporise and disperse with the wind.

Pool Fire The thermal radiation levels were calculated to be as follows:


F2 D5

4

12.5

37.5

378 375

245 259

160 187

Flash Fire The furthest extent of a flash fire was calculated to be:

FZ DS

I 96 102

Table 18: Furthest Extent of a Flash Fire from Methanol Ship Line

I. 3. I . 4.1 Presently IF1 is being dismantled and as of yet information as regards the new owners is not known. The methanol fire resulting from pipe rupture will encapsulate a wide area. The worst case scenario is that the heat wilhadiate as far as 259m. There would be a 1% fatality level after 30 seconds.

Human Consequences

1.3.1.4.2 Environmental Consequences Due to the fact this is an uncontained spillage there will vast quantities of methanol seepage into the soil. When released into the soil, methanol is expected to readily biodegrade, based on the results of a large number of biological screening studies. Further discussion on the environmental consequences will be discussed in the loss of containment section 1.3.3.

I . 3.1.4.3 Risk Control Measures The methanol pipe from the jetty is pressure tested every 5 years to ensure pipe integrity. The methanol line is a continuous welded pipe. As part of the ship unloading procedure prior to the ships arrival the shift supervisor will walk the line and carry out a visual check on the line every 4 hours. When the ship arrives the ships captain is given a Dynea radio which allows him communication between the jetty and Dynea control room which allows for quick action in the case of a major accident scenario. During the unloading process there are levels taken in the control room which are compared to ships pumping rates. Any major deviations, the ships pump will be stopped and valves at

%, Page 31 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11


Overpressure (barG)

dynea

Overpressure Effect (psig)

methanol tank closed and an investigation carried out. Any deviations would be noticed within 20 minutes which would result in approximately 100 cubic meters of methanol available to the fire.

0.3

2

3

1.3.1.4.4 Mitigation Measures Dynea have 2 employees manning the jetty at all times and who are communication with Dynea control room and the ships captain. During this emergency the shift leader will communicate with ships captain to stop ships pumps. He will push emergency stop button on the jetty and this will shut off methanol line valves. The captain will mobilize his crew to remove the ship off the jetty. The shift leader will then communicate to Dynea control to close valves at the methanol tank. This operation will take approximately 30mins. The Emergency Crew Leader will notify the relevant authorities and will mobilize a crew to start foam units to reduce the effects of the fire, if it is safe to so. This operation will take approximately 30mins.

Safe distance@ (probability 0.95 no serious damage beyond this value); projectile limit; some damage to house ceilings; 10% window glass broken

Partial collapse of walls and roofs of houses

Heavy machines (3,000 Ib) in industrial building suffered little damage; steel frame building distorted and pulled away from foundations

1.3.2 Explosions

The following three blast overpressure levels are normally chosen to cover a range of effects of explosion:

@

0.0207

0.14

0.21

Table 19: Effects of

A vapour cloud explosion may be defined as an explosion occurring outdoors, producing a damaging overpressure. In a vapour cloud explosion, a volatile liquid vaporises, and the cloud of vapour travels with the wind, dispersing and diluting as it moves.

If ignition does not take place until a large cloud of vapour has been generated overpressure is developed, with consequent damage to structures and either direct injury or, more likely, indirect injury to persons caused by projectiles or building (“late ignition”), a vapour cloud explosion takes place.

The intensity of the explosion depends on the degree of confinement of the explosion. Most releases of vapour clouds take place in or near buildings and other structures, and so are partially confined. Further, the cloud will not be of a uniform shape, or at a uniform composition. All of these uncertainties make it necessary to generalise, and the fraction of the heat of combustion in an explosion that appears as energy in the shock wave has often been estimated based on observations of incidents and experiments, particularly stemming from military sources.

This fraction is given by the yield, Q. q is the product of two independent yield factors qC and Q,,,, as follows:

Page 32 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11


~ 8 Number:1.0.3 3 1 / I 2/05

qc is the yield factor due to the non-stoichiometry of a cloud with a continuous development of fuel concentration in the explosive part of the cloud; qc is approximately 30%.

q m is the mechanical yield of the combustion. Approximate values of qm are as follows: -

Total confinement: qm . 100% lsochoric combustion: q m 33% Isobaric combustion: qm 18%

- I

The value of q m also depends slightly on the type of gas. -

Where a gas cloud explosion occurs there is probably some form of confinement, and hence qm 33%, and t j 10%.

If there is no confinement, then qm 18%, and 6 5%.

In the case of total confinement, q m loo%, but total confinement means no rupture. If there is rupture of the vessel, then this is similar to a partially confined vapour cloud explosion, and qm 33%.

0 -

Four cases are assessed:

0

0

0

0

Vapour cloud released when roof of Methanol Tank collapses Vapour cloud released when Methanol Tank leaks to bund Vapour cloud released when road tanker spills Vapour cloud released when ship line ruptures

Page 33 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11


Weather Conditions F2

Document Revision: Issue Date: Number:1.0.3 3 1 I1 2/05

D5

- 1.3.2.1 In this scenario, both the fixed and floating roofs of the methanol storage tank collapse. This could be caused by an external event or by mechanical failure. Following collapse of the roof of the tank, the contents of the tank (methanol) vapourise and disperse with the wind.

Vapour Cloud Explosion from Vapours released from Methanol Tank

. - I

Overpressure (barG)

The explosion effects from late ignition were calculated to be:

I


I

I 163,700 I 1049100 Mass of methanol involved in explosion [ka) I

I 0.0207 I 1,187 I 1,316 I 0.14 I 32 1 I 35 1 I

I 0.21 I 252 I 275 I Table 20: Explosion Effects from Late Ignition from Vapours Released from Methanol Tank

1.3.2.1.1 Human Consequences The human consequences due to an explosion can be divided into two categories:

0

0

Direct effects: pressure change caused by the blast can cause injury to sensitive human organs, such as lungs and ears. Indirect effects: Injury due to impact by fragments and debris originating from the explosion. Injury may also arise due to persons or objects being thrown by the blast wave.

The worst case scenario would be a blast overpressure of 0.14barG at 351m from the source. The effects from the blast overpressures would be sufficiently high to cause damage to buildings at the site. The blast overpressure would not impact on the residences in the locality. The main areas of employee population density are in the administration building. This building has a precast concrete frame which would remain intact after explosion which will give some protection to employees. Employees who are working outside within the radius of the explosion are likely to suffer very serious injuries from the explosion.

@

1.3.2.1.2 Environmental Consequences The environmental consequences of a vapour explosion will be minor as the explosion will be of short duration. There will no emission to ground or water thus preventing potential pollution. There is little vegetation around the plant so scorching is unlikely to occur.

1.3.2.1.3 Risk Reduction Measures The methanol tank undergoes non-destructive testing once every five years. This process will show up any defects with the tank. The tank itself is built to a recognised standard, which will be discussed further in the technical section of the Safety Report. It is planned in the third quarter of 2006 to install methanol vapour detection in the methanol bund.

Page 34 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: issue Date: N um ber: 1.0.3 3 1/12/05 0

Weather Conditions F2

I

D5

dynea

. -, Overpressure

(barG)

1.3.2.2 In this scenario, the contents of the methanol storage tank are lost to the bund. This could be caused by an external event or by mechanical failure. The contents of the tank (methanol) vapourise and disperse with the wind.

The bund floor area, net of the cross-sectional area of the tank, is 1,591 m2. The diameter of a circle of this area is 45.01 m.

Vapour Cloud Explosion from Vapours released to Bund from Methanol Tank

I


I

This scenario envisages a loss of containment of the bulk tank, so that the entire bund is flooded. This could be caused by a tank rupture, pipe rupture, pump leak, etc.

0.0207

0.14

0.21


368 82

114 51

93 48

Mass of methanol 2,620 4.9 I involved in exdosion (ka) I

Table 21 : Explosion Effects from Vapours from Methanol Released to Bund

1.3.2.2.1 Human Consequences . The worst case scenario would be a blast overpressure of 0.14barG at 114m from the source. The consequences from the blast overpressure would result in personnel injury and building damage. The effects from the blast overpressures would not be sufficiently high to cause any damage to windows at any of the residences in the locality. The main areas of employee population density are in the administration building. This building has a precast concrete frame which would remain intact after explosion which will give some protection to employees.

@

1.3.2.2.2 Environmental Consequences See section 1.3.1.2.2

I . 3.2.2.3 Risk Reduction Measures See section 1.3.2.1.3

Page 35 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11

1

Weather Conditions


F2 D5 I

I

Mass of methanol involved in explosion (kg)

dynea

4 43

N urn ber: 1.0.3 3 1112105

Overpressure (barG)

1.3.2.3 Vapour Cloud Explosion from Vapours released from Road Tanker

I


I

In this scenario, the contents of a road tanker (19.2 tonnes) are lost to the contained area. This could be caused by rupture of a hose or pipe joint. Methanol would spill into the contained area and drain to the underground sump from which it is automatically pumped to the methanol tank bund. It is assumed that the contained area is 200 m2. The diameter of a circle of this area is 15.96 m. The contents of the tank (methanol) vaporise and disperse with the wind.

0.0207

0.14

0.21


54 99

26 35

23 30

I . 3,2.3. I Human Consequences The worst case scenario will revolve around a 35m radius of the loading bay area. This area is only occupied when a tanker is being loaded. This operation lasts approximately a half an hour, and occurs approximately 10 times a week. While the tanker is loading the operator remains with the load so if there is an explosion, they will be within the 35m zone. The result of the explosion would be 100% fatality to operators at the loading bay and some distortion of the loading bay. The galvanized roof on the loading bay will be blown off. Residents in the locality will not be affected by overpressure. The administration building at the plant will not be affected by the blast overpressure.

1.3.2.3.2 Environmental Consequences See Section 1.3.1.3.2

I . 3.2.3.3 Risk Reduction Measures All production personnel have been trained on methanol loading. The detail for methanol loading is contained in the methanol loading procedure (3.5.50 Methanol loading procedure). All equipment in the loading bay is Ex rated. All methanol pipelines have earthing straps across the flanges to reduce effect of potential difference arising from a flowing liquid. There is signage on entry to the bay that ignition sources are forbidden in the bay. The designated Methanol tankers arriving on site are checked prior to loading for any damage to hatches and connection pieces. All drivers taking methanol off site are site inducted and must have a HAZ Chem license and provide proof of this, each time they take methanol from the site. The Dangerous Goods Safety Advisor (DGSA) checks each new tanker arriving on site and receives its certificate of conformance. The DGSA determines the maximum/ minimum loading capacities of the tanker using the ADR guidelines.

I . 3.2.3.4 Mitigation The loading bay is positioned away from areas of high employee density. In the event of an explosion in the methanol loading the deluge system can be manually operated. The response times etc. are

@

Page 36 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:11

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report dynea

- Document Revision: Issue Date: Number:l.O.3 3 1/12/05

similar to detail described in section 1.3.1.3. This system can be started from a remote location to reduce any further effects from the explosion. The mobile foam unit can be brought to the area and connected to the fire hydrants and can then pump foam from a remote location. As part of the budget in 2006 it is planned to have remote activated deluge system in place at the loading bay. The deluge system is currently in place; however the wiring to the actuated valve is to be completed. This will be

I completed in the first quarter of 2006. I I !

Page 37 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:12

dynea Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number:1.0.3 3 1/12/05

Blast Overpressure (mbar) Pressure (bar)

1.3.2.4 Reactor Headspace Explosion


Flammable and explosive vapours are not normally present in the headspace of reaction vessels in normal operation, because the concentration is below the lower flammable limit, 6%. The vessel is earthed to prevent accumulation of static electricity.

However, the worst case is an explosion involving 70 kg of methanol/formaldehyde vapour. Assuming a 50/50 mixture of methanol and formaldehyde, the distances to blast overpressures are as follows:

Damage Level 1 (heavy damage to buildings and to process equipment)

Damage Level 2 (repairable damage to building and facade damage to dwellings)

Damage Level 3 (glass damage causing injury)

0.36 14

0.18 26

0.03 71

The design pressure of the vessel is 3 barG. Two bursting disks, rated at 1 barG and 1.5 barG provide pressure relief.

1.3.2.4.1 Human Consequences A reactor head space explosion would result in serious injury/ death of personnel working around the reactors and in the control room if the bursting disks were to fail. There would be a maximum of 5 people in this area during day work and 3 during night shifts and weekends. Considerable ongoing work has been taking place to thoroughly evaluate the risk. Dynea and competitor companies have been operating the reactors in this fashion for over 50 years. Analysis of the design and build specifications of the reactor and the DIERS calculations for the bursting disks shows that the system has been designed to fully vent such an explosion and that an overpressure will not occur.

1.3.2.5 Environmental Consequences 0 If the vessel is not significantly damaged, the contents of the reactor can be reworked. In the worst case scenario where the reactor vessel ruptures there will be 34tonnes of a formalin/ methanol mixture to be dealt with. Some of the mixture will be contained within the reactor bund wall which can be placed in IBC’s and reworked. There will be overtopping of the bund wall, and the reactor contents will end up in the process drains and finally in Basin 1. This substance will be contained in Basin 1 and the Basin will be quarantined. Some of the solution may end up on the grass area by the reactors. The degradation processes for the formaldehyde in soil/ water are discussed in 1.3.5.

1.3.2.5.1 Risk Reduction Measures The bursting discs relieve pressure build-up in the reactor and because of this they are classified as safety critical. These bursting discs are on maintenance schedule and are changed at regular intervals. The reactors are built to a specific standard (See technical section). The agitator is also on a maintenance schedule so that seals around the shaft are in good condition reducing the risk of sparks resulting in an explosion.

1.3.2.5.2 Mitigation Measures During the above scenario, foam canons on the reactor ground floor will be used to reduce the toxic effects of the spillage. Some of the reactor contents will be contained within the reactor bund wall. This liquid in the bund can be pumped into IBC’s and reworked. Foam will be sprayed into Basin 1 to

Page 38 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:12


l @ Number:l.O.3 3 1/12/05 I

I

dynea

,

reduce the toxic effect. Water will also be pumped into the Basin 1 to dilute the mixture. The liquid in the basin can be reworked by pumping it to the distillate tank, and from there it can be used in the absorber tower.

@ Page 39 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:12

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: q) Number:1.0.3 3 111 2/05

Blast Overpressure (m bar)

1.3.2.6 Methanol Tank Explosion This scenario envisages that the methanol tank contains no liquid, but is full of methanol vapour, i.e. the inner roof is at the top of its travel. If concentration of methanol vapour is between the upper and lower explosive limits, and a source of ignition is introduced, the vapour/air mixture will explode.

The volume of Tank 4500 m3. At the LEL (6%), the volume of methanol vapour is 300 m3. At the UEL (36.5%), the volume of methanol vapour is 1825 m3.

Pressure (bar) Distance from source centre (m)

The density of Methanol Vapour at NTP is 2.55 kg/m3. The mass of methanol at the LEL is 765 kg. The mass of methanol at the UEL is 4,651 kg.

Damage Level 1 (heavy damage to buildings and to process equipment)

Damage Level 2 (repairable damage to building and facade damage to dwellings)

Damage Level 3 (glass damage causing injury)

The worst case was taken, i.e. all vapour at the UEL.

0.36 53

0.18 105

0.03 263

If an explosion were to occur, involving the entire tank volume at the upper explosive limit, the distances to blast overpressures would be as follows: ID

1.3.2.6.1 Human Consequences A methanol tank explosion would result in serious injury/ death within 105 meters of the tank. It would also cause severe damage to buildings in that area. It would encapsulate the methanol loading area which may escalate the incident. Access to the methanol bund is on a restricted basis only. There may be operators in the vicinity of the bund, during the loading of methanol to road tankers at the methanol loading area. The administration building and occupants would experience level 2 damage (see table above). Residents in the locality may experience damage to windows

@

1.3.2.6.2 Environmental Consequences After an explosion of this magnitude there would be probable damage to the bund wall. Since this scenario deals with a vapour and an empty methanol tank there will be no environmental damage

1.3.2.6.3 Risk Reduction Measures There is non destructive testing of the methanol tank every 5 years. The tank itself is built to a recognised standard. There is a pressure relief valve on top of the tank and a flame arrester. The pressure rating etc. of this equipment will be discussed in the technical section of the report. This equipment is on a maintenance schedule and is maintained at regular intervals. There is a constant feed of Nitrogen to the methanol tank, which will prevent ignition. There are two sources of Nitrogen, the Nitrogen compressor, and Nitrogen bottles for instances when Nitrogen compressor is being maintained. It is planned to have vapour detection in place in 2006.

Page 40 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:12

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: 0 Number:1.0.3 3 1 / I 2/05

1.3.3 Loss of Containment

1.3.3.1 Formaldehyde Gas Cloud A cloud of formaldehyde gas could be released in the event of:

Formalin Tank Rupture Failure of the Catalytic Converter Opening of the Pressure Relief Valve and failure of all Absorber pumps

1.3.3.2 Formalin Tank Rupture Formalin is a solution of formaldehyde in water. At Dynea, formalin is produced as an aqueous solution of strength 55%, and diluted to 50%. The solution is stored at a temperature of up to 6OoC, normally about 50°C to prevent the formation of polymers, i.e. Para formaldehyde.

The vapour pressure of formaldehyde gas over a 50% aqueous solution at 4OoC is extremely low - 5 mm Hg (0.066 atm). At this pressure, a formalin solution would not give off a vapour whose concentration of formaldehyde is above the flammable limit.

@

In the event of rupture of a formalin tank, the liquid would be released into the bund and evaporate. The rate of evaporation depends primarily on the wind velocity, but also on the temperature of the surface under the pool.

There are two formalin tanks. Each is 8 m in diameter, 6 m high, and has a volume of 300 m3. The density of the formalin is1 kg/m; i.e. total contents are 151 tonnes of formaldehyde.

The bund dimensions are 56.5 m x 31.4 m. After allowing for the area taken up by the tank and pump a base, the floor area is 1,160 m2, so the equivalent diameter of the bund is 38 m.

The initial rate of evaporation of formaldehyde from 50% wlw formalin at 30°C was calculated to be:

Initial Rate of Evaporation (kg/s) for wind speed

I 0.012 I 0.030 I Table 25: Initial Rate of Vaporisation from 50% Formalin at 30°C

Page 41 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:12

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: NumberA.O.3 3 111 2/05

The dispersion of formaldehyde gas under various combinations of wind speed and atmospheric stability was predicted to be as follows:

10

Basis Averaging Distance from source centre Time to Concentration (m)

F2 D5 (SI

256 I 99 I US EPA Immediate Danger Level

NIOSH IDLH I 3,600 I 432 I 148 I AlHA ERPG-2 3,600 642 203

1,800 691 216 (evacuate)

I 900 I 750 I 231 I I 10 I 783 I 240 I

Table 26: Dispersion of Formaldehyde under Various Combinations of Wind Speed and Atmospheric Stability

I . 3.3.2. I Human Consequences The effects from a formalin spillage (50% Formaldehyde) from a formalin tank (T402, T403) will be experienced by personnel and members of the general public in the vicinity of the plant. There is an immediate danger to life and health within 432m of the site. Formaldehyde poisoning is a disorder brought about by breathing the fumes of formaldehyde. The major symptoms may include eye, nose, and throat irritation; headaches; and/or skin rashes. Formaldehyde has a distinctive smell and would be noticed immediately. Dynea personnel would don breathing apparatus.

I . 3.3.2.2 Risk Reduction Measures The tanks are constructed to recognised standards (See technical section of safety report). Both these tanks undergo non destructive testing to ensure tank integrity. The tank is surrounded by a bund wall which will contain some of the spill. There are level transmitters on the tank which alarm in the control room at high and low levels, which will allow for, immediate action in the case of an emergency. The legislation (SI 476of 2000) requires that information is to be provided to the general public regarding Seveso 2 sites. An information pack has been developed and has been distributed to the general public illustrating the actions to be taken in the event of a major formalin leak.

I . 3.3.2.3 Environmental Consequences

Loss of containment of formalin would require:

(a) (b)

Loss of contents of a formalin tank to bund and leakage from bund Loss of contents of more than one formalin tank to the bund

In the event of loss of contents of a formalin tank to bund and leakage from bund, formalin solution would be released to the surrounding area.

If the leak was to the hard standing in the yard, the formalin would enter the drainage system, which would be discharged to the retention basin.

Page 42 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:12


@ Number:1.0.3 3 1/12/05

0 If the leak was to under the hard standing, or to ground beneath the bund, formalin could seep into the ground. In this case, formalin would drain to the groundwater.

The EPA Report Measurement and Modelling of Nutrient Dynamics of Two Estuaries in Ireland - Wexford and Cork Harbours - Synthesis Report (2001) gives the following information on Cork Harbour:

Characteristic Value

I Estuary area (ha) I 8,585

I Estuary length (km) I 17.72

Maximum width (km) 6.14

Width at mouth (km) 1.65

Main channel width at mouth (km) 1.65

Maximum depth (m) 28

Maximum depth at mouth (m) 28

I Freshwater catchment area (ha) 1 186,000

I Annualised catchment rainfall (mm) I 830

I Annual freshwater inputs (m3/s) I 41

180,000

Volume (m3) 642 x l o 6

Ration of prism to volume 0.10

Table 27: EPA Report Information on Cork Harbour

Page 43 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:12


Figure 4 in the EPA report shows that the main channel is well-defined and narrow, and between 10 and 20 m deep from Marino Point to the mouth of the harbour.

Figures 15, 16, 17 and 18 in the EPA report show the vector plots of current velocities in Cork Harbour during different stages of spring tides (high water, mid-ebb, low water and mid-flood). These show that the direction of flow at Marino Point reverses on the flood tide.

If there was an uncontained total loss of containment of a formalin storage tank, the rate of discharge of formalin to the harbour would be slow, as the liquid would have to seep through the ground and travel along the saline water surface. Hence, there is no credible risk of water supplies being contaminated.

In the case of loss of containment of storage tanks, the total quantity is very small in relation to the total capacity of the Harbour.

0 The BOD load released in the event of loss of containment of a tank of formalin would be 110,000 kg. This is equivalent to over three times the daily assimilative capacity of Cork Harbour at Marino Point, and one third of the daily assimilative capacity at the Ram’s Head Bank

The average concentration in the tidal prism volume would be 1.725 mg/l. This concentration is well below the toxicity levels for rainbow trout, but comparable to the levels for other aquatic organisms.

t.dwever, the above is the worst case situation. In reality, some formalin would be retained in the tank farm, and the portion released would take some time to seep through the ground, or over the surface. Further, the scouring action of the tide, and the assimilative capacity would reduce the impact.

On the other hand, the concentration would not be uniform throughout the harbour, and local concentrations would be higher.

The impact would depend on the stage of the tide. One could infer from the vector diagrams that most of the formalin would be swept out to sea with the main current, although some would spread to either side of the main channel, where there are larger areas of shallower water.

All of this assumes that the bunding is ineffective, and this is unlikely as integrity testing has been @ carried out.

I . 3.3.2.4 Mitigation The pfnd is designed to offer secondary containment during a tank rupture. It has been shown by the HSE that bunds may not be able to cope with a catastrophic failure of the tank and the sudden release of a large volume of liquid. The HSE report identifies a number of potential scenarios:

0

0

0

Bund overtopping: The momentum of the liquid causes a proportion of the tank contents to flow over the top of the bund Bund collapse: The forces exerted on the wall may cause bund collapse Collapse of bund following collision with tank debris. There would be a force in the opposite direction to liquid flow following catastrophic failure of the tank which could propel the tank (much lighter than contents) towards the bund wall.

The resin bund height is lower than the tank height, so the most likely event is overtopping of the bund wall. Another study carried out by the HSE” illustrates that the amount of overtopping was largely dependent on height of liquid in the tank and the bund height.

12‘Effects of secondary containment on source term modelling’, WS Atkins Consultants Ltd, Contract Research Report 324/2001, prepared for the HSE, UK.

Page 44 of 65

@

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:12

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: 0 Number:1.0.3 3 111 2105

I

dynea

The quantity lost to overtopping can be calculated .The quantity overtopped is calculated to be approximately 70%.

The means that 70% of the tank will overtop the bund wall equating to 210 cubic meters of formalin assuming tank is full. (The above calculation is simplistic in that it concludes that a bund capable of containing 700% of tanks contents needs to be the same height as the tank). This liquid will be retained in Basin 1 through the rainwater drainage system. 90 cubic meters formaldehyde solution will be contained within the bund. The formalin that is left in the ruptured tank will be pumped into the other formalin tank (T402lT403). Operators with full breathing apparatus will spray foam on the formalin on the road way in front of tank farm to reduce vapours and toxic effects of formalin. The formalin in the bund can be pumped into IBCS and used in the process. Foam will also be pumped into Basin 1 to reduce effects of vapour

I

Page 45 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:12


Component

I

% wlw

dynea

concentration (PPm)

- Document Revision: Issue Date: Number:l.O.3 3 1/12/05

Basis Averaging Distance from source centre Time to Concentration (m)

F2 D5 (SI

I

1.3.3.3 Failure of Catalytic Converter

50

20

10

In the event of failure of the catalytic converter, all the gases would be discharged through the converter stack for up to one hour.

US EPA Immediate 3,600 6.4 8.1 Danger Level

NIOSH IDLH 3,600 20 13

AlHA ERPG-2 3,600 28 17

1,800 29 18

900 30 20

10 31 22

(evacuate)

Following modifications to the absorber tower carried out as part of the emissions reduciion programme in 2001, the concentration of formaldehyde has been reduced from 1,25Omg/m to 240mg/m3. With a gas flow rate of 8,000 m3/hr, this is equivalent to a discharge of 1.920 kglh; (0.00053 kg/s). However, in an attempt to model worst case scenarios, the older figure of 1,25Omg/m was use as an input to the modelling software.

The gas has the following composition:

I Nitrogen I 89 I I Oxygen I 6 I I Watervapour I 5 I 1 Formaldehyde I 0.1 I Table 28: Composition of Exit Gas from Catalytic Converter

The diameter of the stack is 400 mm, and therefore the efflux velocity is 17.68 m/s.

This scenario was modelled using PHASTMicro and ISCST3.

With PHASTMicro, the dispersion of formaldehyde gas under various combinations of wind speed and atmospheric stability was predicted to be as follows:

Page 46 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:12

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: @ Number:l.O.3 3 Ill 2105

Conditions of Wind Speed and Atmospheric Stability

e I

Page 47 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:12


@ Number:1.0.3 3 1 /I 2/05

Weather Maximum Condition Concentration of

Formaldehyde (ppm)

With ISCST3, the following results are obtained:

Using 1989 Roche’s Point meteorological data, the highest I-hour average ground level concentration (GLC) predicted was 973 pg/m3 (0.8 ppm) at receptor 77800, 69500, a distance of 440 m from the stack.

Distance downwind of Source (m)

The maximum concentrations reached, and the distance from the source for weather conditions D5 and F2 were predicted to be as follows:

I D5 I 0.015 I 150 I r-7 I 0.26 I 150 I

~

Table 30: Maximum Formaldeyde Concentrations and Distance from Source for Conditions D5 and F2 after Catalytic Converter Release

ISCST3 is more optimistic than PHASTMicro, and predicts lower concentrations of formaldehyde.

1.3.3.3.1 Human Consequences

The modelling predicts that effects from the above scenario will not affect the residents in the locality. The ILDH value occurs at 20 meters from the source. Due to the smell of the gas all employees outside will have time to enter the main building and use the breathing apparatus provided. The normal wind direction is south-westerly, which would mean the plume of formaldehyde gas would be directed away from the plant and away from immediate locality.

I . 3.3.3.2 Environmental Consequences

The environment at risk from such a release includes:

0 Flora 0 Fauna

Formaldehyde gas could lead to distress among birds flying into the plume, but the plume is relatively narrow, short-lived in duration and disperses to low concentrations quite quickly. The risk to birds is further reduced as birds can much take evasive action more easily than humans, as they can move in three directions, whereas humans can only move in two directions. High level formaldehyde could affect high vegetation, i.e. tall trees.

Formaldehyde gas at low elevation, i.e. when the plume descends to ground level, could cause distress among earth-bound fauna and low level vegetation. The only incident that could give rise to high ground level concentrations is a spill of formalin to the bund. This has been discussed earlier in this report.

1.3.3.3.3 Risk Reduction Measures The plant equipment is built to recognized standards. The location of the equipment is at the northern end of the site where employee traffic in this area is quite low. As part of Dynea IPC License there are continuous air emissions analysers in place and air sampling is carried out twice monthly, both of these systems will show up any issues with regard to functioning of the catalytic converter.

Page 48 of 65

9 r

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:12

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number:l.O.3 3 111 2/05

Component

dynea

kglhr

1.3.3.4 Opening of the Pressure Relief Valve and failure of all Absorber pumps In the event of opening of the Pressure Relief Valve on the Absorber outlet, and coincident failure of all Absorber pumps, it is estimated that 1 tonne of formaldehyde could be discharged over half an hour.

I 1 t

The gas stream has the following composition:

I Nitrogen I 30,316 I r- ~ Oxygen I 2,687 I

I ~~

T W a t e r Vapour 1 2,773

I 43 I ~~ r Methanol

I 552 I

Formic Acid

Dimethylether

Formaldehyde 2,891

Table 31: Absorber Gas Stream Concentration

The concentration of formaldehyde is 7.33%.

The diameter of the PRV discharge vent is 450 mm, and the density of the gas is 0.78 kg/m3 (temperature 16OoC) and therefore the efflux velocity is 88 m/s.

This scenario was modelled using PHASTMicro and ISCST3.

With PHASTMicro, the dispersion of formaldehyde gas under various combinations of wind speed and atmospheric stability was predicted to be as follows:

l j

Page 49 of 65 I'

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:12


Concentration Basis Averaging Time

(SI (PPm)

Document Number:l.O.3

Distance from source centre to Concentration (m)

F2 D5

Revision: Issue Date: 3 111 2/05

US EPA Immediate Danger Level

NIOSH IDLH

3,600 2.0 2.5

3,600 8 11 ~~ ~

AlHA ERPG-2 (evacuate)

3,600 23 29

1,800 23 29

900 23 29

10 23 29

Table 32: Dispersion of Formaldehyde Gas from Absorber under Various Conditions of Wind Speed and Atmospheric Stability

Weather Maximum Condition Concentration of

Formaldehyde (ppm)

With ISCST3, the following results are obtained:

Distance downwind of Source (m)

Using 1989 Roche's Point meteorological data, the highest 1 -hour average ground level concentration (GLC) predicted was 26,564 pg/m3 (22 ppm) at receptor 77750, 69450, a distance of 440 m from the stack.

05

F2

The maximum concentrations reached, and the distance from -the source for weather conditions D5 and F2 were predicted to be as follows:

4.7 350

1.5 2,000

Table 33: Table 39: Maximum Formaldehyde Concentrations and Distance from Source for Conditions D5 and F2 after Absorber Release

ISCST3 is more optimistic than PHASTMicro, and predicts lower concentrations of formaldehyde. Both modes predict that unsafe concentrations will not occur outside the site.

The consequences human and environmental are similar to 0.

1.3.3.5 Methanol Vapour Cloud A methanol vapour cloud could be generated from a pool of methanol liquid:

0 Methanol tank rupture 0

0

Methanol road tanker loading spill Methanol ship offloading - spillage to land

Page 50 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:13


1.36

1.3.3.6 Methanol Tank Rupture In this scenario, the contents of the methanol storage tank are lost to the bund. This could be caused by an external event or by mechanical failure. The contents of the tank (methanol) vaporise and disperse with the wind.

The bund floor area, net of the cross-sectional area of the tank, is 1,591 m2. The diameter of a circle of this area is 45.01 m.

This scenario envisages a loss of containment of the bulk tank, so that the entire bund is flooded. This could be caused by a tank rupture, pipe rupture, pump leak, etc.

I

2.03

The initial rate of evaporation of methanol was calculated as follows:

Averaging Time Concentration (ppm) (SI

Rate of Evaporation (kgls)


F2 D5

25,000 (IDLH)

250 (OEL-STEL)

The dispersion of methanol vapour under various combinations of wind speed and atmospheric stability was predicted to be as follows:

3600 97 78

900 260 102

1.3.3.6.1 Human Consequences There is an immediate danger to life and health within 97m of the vapour source. There will be production personnel working near the methanol loading area and the urea store which are within the 97m of the methanol source. People in the vicinity of methanol vapour will experience intoxicating effects as Methanol is an alcohol. Methanol will be quickly absorbed through the skin and by inhalation. The liver will metabolise the methanol to formaldehyde and formic acid which will be removed from the body. Methanol is a hydrophilic compound and will locate itself to areas of high water concentration usually the eyes. This can result in eye damage. Methanol has the characteristic smell of alcohol which will alert people outdoors to move indoors. This incident will have no impact on local residents.

1.3.3.6.2 Environmental Consequences The environmental consequences from a large spill in the methanol bund will be contained within the bund. Adding foam to the bund will reduce the vapour pressure of the liquid and reduce toxic effects.

Page 51 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:13


The bulk storage tank holds 3,600 tonnes of methanol, and is totally bunded to 110% of the tank capacity. It is only in the event of tank rupture, and at the same time leakage from the bund, or rupture of the bund, that liquid methanol would be released to the environment.

In the event of leakage or rupture of the bund, methanol would be released to the surrounding area, and would seep into the ground, or overflow to Cork Harbour. Methanol seeping into the ground would rapidly reach the water table, and then slowly seep into Cork Harbour.

0 The BOD load released in the event of loss of containment of the methanol bulk tank would be 4,104T. This is many times the daily assimilative capacity of Cork Harbour at Marino Point.

0 The average concentration in the tidal prism volume would be 36 mg/l. This concentration is well below the toxicity levels shown.

However, the above is the worst case situation. In reality, some methanol would be retained in the tank and tank bund, and the portion released would take some time to seep through the ground, or over the surface. Further, the scouring action of the tide, and the assimilative capacity would reduce the impact.

On the other hand, the concentration would not be uniform throughout the harbour, and local concentrations would be higher.

As discussed earlier (formalin spill), if there was an uncontained total loss of containment of the methanol storage tank, the impact would depend on the stage of the tide. Most of the methanol would be swept out to sea with the main current, although some would spread to either side of the main channel, where there are larger areas of shallower water.

This assumes that the bunding is ineffective, and this is unlikely as integrity testing has been carried out.

Methanol vapours would be released to the atmosphere from any spill. The dispersion of methanol vapours from a spill of formalin to the bund has been examined elsewhere in this report with regard to toxicity to humans.

The quantity of methanol vapours from a leak from an overflowing bund would be somewhat greater than if the leak were contained within the bund. However, the concentration of methanol vapours from a leak of methanol to groundwater and thence to Cork Harbour would be very small, as it would take some time for the methanol to seep through the ground. The slow discharge rate would give rise to a low Concentration. It is not considered that any tangible risk would be posed to the environment by methanol vapours from this incident.

1.3.3.6.3 Risk Con fro/ Measures There are access restrictions to the methanol bund. The methanol tank is constructed to a recognised standard and non destructive tests are carried out on the tank every 5 years. There has been integrity tests carried out on the bund. As part of the budget for 2006 vapour detection will be put in place.

1.3.3.6.4 Mitigation Measures The bund is designed to offer secondary containment during a tank rupture. It has been shown by the HSE 10that bunds may not be able to cope with a catastrophic failure of the tank and the sudden release of a large volume of liquid. The HSE report identifies a number of potential scenarios:

0

Bund overtopping: The momentum of the liquid causes a proportion of the tank contents to flow over the top of the bund Bund collapse: The forces exerted on the wall may cause bund collapse

Page 52 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:13

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number: 1.0.3 3 111 2/05

0 Collapse of bund following collision with tank debris. There would be a force in the opposite direction to liquid flow following catastrophic failure of the tank which could propel the tank (much lighter than contents) towards the bund wall.

The resin bund height is lower than the tank height, so the most likely event is overtopping of the bund wall. Another study carried out by the HSE13 illustrates that the amount of overtopping was largely dependent on height of liquid in the tank and the bund height. The quantity overtopped is calculated to be between 30 and 40%.

As discussed earlier the calculation used in the research paper carried out by HSE for bund overtopping is simplistic and does not reflect the actual degree of containment accurately. Further mitigation measures involve employees with full breathing gear starting the bladder tank and pouring foam into the bund to prevent escalation of the incident. Other foam units from around the site will be used if required.

13'Effects of secondary containment on source term modelling', WS Atkins Consultants Ltd, Contract Research Report 324/2001, prepared for the HSE, UK.

Page 53 of 65

@ I

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:13

dynea Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number:l.O.3 3 1112105

Averaging Time Concentration (ppm) (SI

I 1.3.3.7 Methanol Road Tanker Loading Spill In this scenario, the contents of a road tanker (19.2 tonnes) are lost to the bund. This could be caused by rupture of a hose or pipe joint. Methanol would spill into the contained area and drain to the underground sump from which i t js automatically pumped to the methanol tank bund. It is assumed that the contained area is 200 m . The diameter of a circle of this area is 15.96m. The contents of the tank (methanol) vaporise and disperse with the wind.


F2 D5

The rate of evaporation depends primarily on the wind velocity, but also on the temperature of the surface under the pool.

25,000 (IDLH)

250 (OEL-STEL)

The initial rate of evaporation of methanol was calculated as follows:

3600 28 27

900 162 70

Initial Rate of Evaporation (kgls) ~1

See section 1.3.2.3.3 for detail ! ?

I 0.13 I 0.17 I

Page 54 of 65 ~ i i

Table 36: Initial Rate of Evaporation of Methanol Following Methanol Road Tanker Loading Spill

The dispersion of methanol vapour under various combinations of wind speed and atmospheric stability was predicted to be as follows:

1.3.3.7. I Human Consequences From the modelling of this scenario, the effects from this MAS will be contained within the site. Residents in the locality will not be in danger from the effects. A person working in the area will have time to move indoors. As mentioned before in this section, an operator will only be in this area 10 times a week for a half an hour.

I . 3.3.7.2 Environmental Consequences Methanol could be spilled and released to the environment from the road tanker loading area. However, the maximum volume is very small, 20 m3. While the nature of ecological damage would be the same as for the bulk tank, the potential scale would be much less.

1.3.3.7.3 Risk reduction Measures

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:13

.

25,000 (IDLH)

250 (OEL-STEL)

dynea

3600 96 102

900 2200 367

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number:1.0.3 3 1/12/05

1.3.3.7.4 Mitigation See section 1.3.1.3.4 for detail

1.3.3.8 (A spill to sea from the ship carrying methanol is outside the scope of the site, and is therefore not included in this assessment.)

Methanol Ship Offloading - Spillage to Land

In this scenario, the pipeline carrying methanol from the ship to the bulk tank is ruptured, and methanol pours on to the ground. In this analysis, it was assumed that the rupture takes place approximately half way between the jety and the methanol tank. The assumed pumping rate is 350 m /hr, i.e. 280 tonnes/hr or 77.8 kg/s. It is assumed that this continues indefinitely. The model does not allow for leaks of limited duration. It is however expected that the leak would be detected and the pump stopped within 5 minutes.

The liquid methanol continues to spread around the source of the leak until the rate of vaporisation equals the rate of leakage. That is a steady-state condition. However, as the duration of the leak is only 5 minutes, it is unlikely that steady state conditions will be reached. There is no containment.

The contents of the tank (methanol) vaporise and disperse with the wind.

The rate of evaporation of methanol was calculated as follows:

Table 38: The Rate of Evaporation from a Methanol Ship Line Loading Spill

The dispersion of methanol vapour under various combinations of wind speed and atmospheric stabilitywas predicted to be as follows: e

Environmental Risk The volume of methanol that could be spilled and released to the environment from a rupture of the jetty pipeline would be much less than from the bulk tank. While the nature of ecological damage would be the same as for the bulk tank, the potential scale would be much less. The degradation processes of methanol in soil and water has been discussed in previous sections.

@ Page 55 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:13


I

dynea Number:1.0.3 3 Ill 2/05

1.3.4 Domino Effects

Dynea and IF1 are neighbouring plants. The IF1 plant is being dismantled at the time of writing the report. The report will be reviewed once knowledge of the new occupier of the IF1 site is known and what work will be carried out at the site. Domino effects are considered with reference to:

0 Dynea site 0 IF1 site

1.3.4.1 Dynea Site Major accidents at the Dynea site that could have an effect on the adjoining IF1 site include:

0

Loss of containment of the methanol tank into the bund Rupture of pipe downstream of Formox reactor Loss of containment of a formalin tank into the bund

1.3.4.1.1 In the event of loss of containment of the methanol tank into its bund, the OEL-STEL could be exceeded under certain weather conditions within the IF1 site. However, assuming that mitigating action was taken by Dynea to cover the pool of liquid, the impact would be transitory. The IDLH value would not be exceeded off the Dynea site.

Loss of Containment of the Methanol Tank into the Bund

1.3.4.1.2 In the event of failure of the incinerator or lifting of the pressure relief valve (with failure of Absorber pumps, a plume of gas containing formaldehyde would be emitted. If the wind were blowing towards IF1 it is unlikely that unsafe concentrations would be generated off-site, but the plume might lead to respiratory difficulties on the IF1 site

Failure of the catalytic or Lifting of Pressure Relief Valve

1.3.4.1.3 In the event of loss of containment of a formalin tank into its bund, a plume of formaldehyde vapour would be emitted. If the wind were blowing towards IF1 the plume could lead to respiratory difficulties on the IF1 site.

Loss of Containment of a Formalin Tank into the Bund

@

Page 56 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:13


dynea Number:l.O.3 3 1/12/05

1.3.4.2 IF1 Site At present the IF1 plant is being dismantled and the only scenario which could have an impact at Dynea is:

0 Rupture of methanol pipeline during ship offloading as a result of decommissioning work on the IF1 facility

1.3.4.2.1 In the event of rupture of the methanol pipeline while ship offloading was in progress, a major spillage of methanol would result at the jetty. Concentrations of methanol vapour could exceed the OEL-STEL within the IF1 site:

0

0

Rupture of Methanol Pipeline during Ship Offloading

In adverse weather conditions, and In particular if the wind is blowing towards IF1

Further, there is a substantial risk of ignition of the methanol, which could result in a pool fire, a jet fire, a flash fire or a vapour cloud explosion.

1.3.4.2.2 Transport of Hazardous Materials The transport of methanol and formalin by road is not considered to fall within the scope of the SI 476 of 2000, and the consequences of a release are not assessed here.

Dynea ensures that it complies with all statutory requirements in relation to road transport of these materials.

Page 57 of 65 I <

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:13

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . -. . . . . . . . . . -. . - - - . . . - . . . -. . . . . . . . . -

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number1.0.3 3 111 2/05

1.3.5 Major Accident Scenarios with Environmental Impact

Major-accident scenarios with environmental impact comprise all of the above. The descriptions of the consequences of loss of containment above include environmental impact.

The half-life of a substance is the time required for 50% reduction in the mass released or present. The half-life depends on numerous factors including: the nature of the release, quantity of the release, and physical, chemical and microbiological characteristics of the impacted media.

1.3.5.1 Methanol Methanol occurs naturally in the environment as a result of various biological processes in vegetation, micro-organisms, and other living species. A large release of concentrated methanol to ground water, surface water, or soil has the potential to adversely impact the affected environment.

The half-life of methanol in soil, in surface water and in groundwater is 1-7 days. The half-life in the @ air is 3-30 days.

When released into the soil, methanol is expected to readily biodegrade, based on the results of a large number of biological screening studies, which include soil microcosm studies, and to leach into groundwater. Its miscibility in water and log kW (-0.77) suggest high mobility in soil. Based on a vapour pressure of 92 mm Hg at 20°C, rapid evaporation from dry surfaces can be expected to occur. The biodegradation of methanol can occur under both aerobic (oxygen present) and anaerobic (oxygen absent) conditions.

~

I

The important environmental fate process for methanol in water is biodegradation. A large number of screening studies have found methanol to be significantly biodegradable. Aquatic hydrolysis, oxidation, photolysis, adsorption to sediment, and bioconcentration are not significant.

“Methanol is significantly less toxic to marine life than crude oil or gasoline, and many of the effects of short term exposure are temporary and reversible. The Office of Pollution Prevention and Toxics indicated that methanol is essentially non-toxic to the four aquatic fish species that were tested. A large methanol spill into surface water would have some immediate impacts to the biota in the direct vicinity of the spill. However, because of its properties (i.e., methanol readily mixes with water and evaporates quickly in the atmosphere) methanol would rapidly dissipate into the environment, and within fairly short distances from the spill would reach levels where biodegradation would rapidly oc~ur . ’ ’ ’~

When released into the air, methanol is expected to be readily degraded by reaction with photochemically produced hydroxyl radicals and to be readily removed from the atmosphere by wet deposition. Atmospheric methanol can also react with nitrogen dioxide in polluted air to yield methyl nitrite. Because of methanol’s water solubility, rain would be expected to physically remove some from the air; the detection of methanol in a thunderstorm’s water tends to confirm this supposition.

1.3.5.2 Formaldehyde Aqueous solutions of Formaldehyde are expected to be slightly toxic to aquatic life. The LC5,J96-hour values for fish are between 10 and 100 mg/l. The methanol portion is expected to be slightly toxic to aquatic life. The LC5d96-hour values for fish are between 10 and 100 mg/l.

Evaluation of the Fate and Transport of Methanol in the Environment, Drepared for the 14

American Methanol Institute bv Malcolm Pirnie, Inc, Januarv 1999, Ref 3522-002 I

Page 58 of 65

I i:

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:13


1

dynea Number:1.0.3 3 1/12/05

When released into the soil, formaldehyde material is expected to leach into groundwater. While formaldehyde is biodegradable under both aerobic and anaerobic conditions, its fate in soil is unknown.

When released into water, formaldehyde will biodegrade to low levels in a few days. Little adsorption to sediment would be expected to occur. In nutrient-enriched seawater there is a long lag period (approximately 40 hr) prior to measurable loss of added formaldehyde by presumably biological processes. Formaldehyde is slightly persistent in water, with a half-life of 2-20 days15. Its fate in groundwater is unknown. This material is not expected to significantly bioaccumulate. About 99% of formaldehyde will eventually end up in air; the rest will end up in the water.

As well as being directly emitted to the atmosphere, formaldehyde is formed as a result of photochemical reactions between other chemicals in already polluted air. These reactions may account for most of the formaldehyde in the air in some areas. This input is counterbalanced by several important removal paths. It both photolyzes and reacts rapidly with reactive free radicals, principally hydroxyl radicals, which are formed in the sunlight-irradiated atmosphere. The half-life in the sunlit troposphere is a few hours. Reaction with nitrate radicals, insignificant during the day, may be an important removal mechanism at night. The initial oxidation product, formic acid, is a component of acid rain. Because of its high solubility there will be efficient transfer into rain and surface water which may be an important sink. One model predicts dry deposition and wet removal half-lives of 19 and 50 hr, respectively. Although formaldehyde is found in remote areas, it is probably not transported there, but rather a result of the local generation of formaldehyde from longer-lived precursors which have been transported there.

l5 State of Knowledae Report: Air Toxics and Indoor Air Quality in Australia 2001 Environment Australia 2001

0 Page 59 of 65 1

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:13

I

Ref. Incident Type of No. Incident

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number:l.O.3 3 1/12/05

Fatal Effects Distance (m)

1.4 Summary of Consequences of Major-Accident Scenarios

The consequences of major accidents are summarised in the following table.

Table 40: Distance to Fatal Effects from Major Accident Scenarios

VCE = Vapour Cloud Explosion Note: all scenarios have some potential for impact other than on human beings.

Page 60 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:13

dynea

Category

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Revision: Issue Date: Number:l.O.3 3 1/12/05

Range

1.4.1 Likelihood of Major Accidents

A

B

7.4.7.7 Hazard Ranking The effects of major accident scenarios were classified as low, medium and high, as follows:

<50 m

50-250 m

Radiation

Ranking

Low I 4 I 0.3

rable 41: Basis for Hazard Ranking

In Table 41, the shaded cells are those distances or effect levels at or above which fatalities could occur. The distances are those for a 1% fatality level. Locations closer to the plant than these distances will have a higher fatality level, and those further away will have a lower fatality level, i.e. virtually zero. As concentrations of formaldehyde and methanol'that will give a 100% fatality level are not known, it is not possible to predict these distances.

The scenarios were ranked in order of decreasing distance to the onset of fatal effects, and classified as follows:

Table 42: Hazard Ranges

Page 61 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:13

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Number: 1.0.3 Revision: Issue Date:1/12/05

Event Incident Distance to 1% fatality level (m)

I

Risk of fatality yr-I

duma

5

6 Q)

1.4.1.2 Risk Estimation The effects of explosions and fires are almost entirely independent of direction. However, the effects of releases of toxic gases and vapours depend on the direction of the wind and atmospheric stability.

The effects of incidents 5 and 6 in Table 43 are not direction-specific, and the risk to an individual continuously present at the maximum effect distance (distance to 1% fatality) is as follows:

Prolonged Fire in Methanol Tank Bund 67 6 x

Methanol to Bund Vapour Cloud Explosion from Release of 35 1 1.9 x

The effects of incidents 1, 2, 3, 4 and 7 are direction specific. The risk to an individual depends on the location of that individual. The risk data used for risk estimation are form reputable scientific sources and are consistant with the data available at the time. The engineering consultant Don Menzie & Associates carried out this analysis and all information regarding data used and source can be got through his office on request.

Page 62 of 65

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:13

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Number: Revision: Issue Date:

I

dynea

1.4.1.3 Tolerable Risk Criteria

I. 4.1.3.1 Individual Risk The UK HSE in its publication Risk criteria for land-use planning in the vicinity of major industrial hazards states that the HSE will use the figure of 1 in a million per year for the lower bound for a typical pattern of user behaviour in a development.

As a cross-section of the population contains a proportion of highly vulnerable people for whom a 'dangerous' dose would likely result in death, this criterion equates to about 1 in a million per year chance of death for such people.

For the majority of the population, assessments done by HSE suggest that this corresponds to a risk of about 1/3 in a million per year of death, since this is the risk of receiving a somewhat higher dose which would be expected to result in the death of 50% of the population.

HSE suggests that a level of 1/3 in a million per year of a 'dangerous' dose or worse would be trivial even for such cases as homes for the elderly, caring institutions, long-stay hospitals etc.

Q

For hazards which are involuntary and with little immediate benefit to the people at risk, HSE will use an upper limit of 10 in a million per year of a dangerous dose or worse, for all development cases above a certain size. This implies that the more vulnerable members of the population are at a risk of death of about 10 in a million per year.

In using these criteria, HSE would automatically indicate 'negligible risk' for proposals below the lower bound for developments such as housing where a particular person might well be present most of the time.

HSE would similarly automatically indicate 'substantial risk' for proposals with a substantial number of people (25 or more people) above the upper limit since there would probably be one or more highly susceptible people in such a number.

For proposals where the risks lie between these values, HSE would consider whether there are features of detail which tend to justify more or less stringent advice.

For the Dynea site, most major incidents assessed will not give rise to effects outside of the DyneaAFI site. For those that do give rise to a risk of fatality outside of the DyneaIlFI site, the highest risk is from a large spill of formalin to the tank farm bund. This is 1.3 x and is in a SSE direction from the centre of the tank farm bund. The off-site effect only occurs during atmospheric stability conditions F. During atmospheric stability conditions D, the effect is confined to the site. The risk of 1.3 x has been calculated on assumption that no mitigation takes place, e.g. covering the spill with foam.

e

When the directional effect of toxic releases is taken into account, very few of the major accident scenarios assessed lead to an individual risk exceeding that recommended by the UK HSE.

Appendix 18 shows the risk contours fro the site.

1.4.1.3.2 Societal Risk

Page 63 of 64 Q

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:14

Dynea Ireland Limited Standard Operating Procedure Control of Major Accident Hazards Involving Dangerous Substances Regulations Safety Report Document Number: Revision: Issue Date: dunea

The HSE states that there is at present no clear consensus on criteria for societal risk, and it is not even clear how best to describe such risk. The FIN curve is a difficult concept, and it is not apparent how to compare two FIN curves for two different situations.

In view of the absence of residential populations and very low industrial population levels within the off-site areas affected, F/N curves have not been prepared.

Page 64 of 64

For

insp

ectio

n pur

pose

s only

.

Conse

nt of

copy

right

owne

r req

uired

for a

ny ot

her u

se.

EPA Export 25-07-2013:20:10:14

Attachment No. B.9 (extract from Safety Report prepared ...

Documents

Transcript of Attachment No. B.9 (extract from Safety Report prepared ...