Lessons from a Management of Change Incident

Nigel Cann, Arup

FIChemE, CEng, CEnv, RPEQ

Nigel.cann@arup.com

2

What we will cover…

• Timing of incident

• Plant process

• Plant Layout

• Incident Event

• AcciMap of Incident

• Actions that followed

• What questions do you have?

Agenda

33

Incident Timing

Timing

5 Oct 98 – I started

4

Production Process

STRIPPING

COLUMN

DEGASSER

AUTOCLAVES

STEAM

ADDITIVES

VCM TANKER

CHARGE WATER

VCM GAS

HOLDER

LIQUID VCM STORAGE

VCM RECOVERY

PLANT

BAGGING AND

PAL LET IZ ING

BULK SUPPL Y

SLURRY

TANK

STORAGE

SIL O

FLUID BED DRYER

CENT RIFUGE

PACKAGED SUPPL Y

Production Process

Plant Layout

5 Layout

6 Layout

7

8 The Incident

9

AcciMap – Modification Control Incident

AcciMap of Modification Control Incident

Accident

Sequence

Governance /

Organisational

Regulatory

Outcomes

3500kg VCM LoC

via steam trapsVCM is in Utility

Steam System

Operator

missed

H2O/VCM

interface

Disperses in

atmosphere

or absorbed

in water

spray

Human and

Environmental

Factors Was Operator

present?

Liquid VCM in

Receiver

Reliance on NRV

Cold weather –

autumn night

1. Poor Mod Control

paper based system

Lower SEPP VCM

boundary limits

1. HAZOP boundary

not including

existing plant when

additional capacity

added

3. Poor Regulatory

Oversight

Back pressure in

Receiver

Orifice Plate

inserted when

additional

production stream

added

Equipment and Design

Steam used to

scrub Receiver

Water

Orifice Plate

blocked by ice

Block in VCM

vapour line to

Recovery

Water mostly

in other

Recovery

Tank

Operator observation of

difficult venting not addressed

4. Loss of

Plant learning

culture

2. Utilities connected

to Process

Organisation

focus on

Environmental

Improvements

10 AcciMap of Modification Control Incident

Accident

Sequence

Governance /

Organisational

Regulatory

Outcomes

3500kg VCM LoC

via steam trapsVCM is in Utility

Steam System

Operator

missed

H2O/VCM

interface

Disperses in

atmosphere

or absorbed

in water

spray

Human and

Environmental

Factors Was Operator

present?

Liquid VCM in

Receiver

Reliance on NRV

Cold weather –

autumn night

1. Poor Mod Control

paper based system

Lower SEPP VCM

boundary limits

1. HAZOP boundary

not including

existing plant when

additional capacity

added

3. Poor Regulatory

Oversight

Back pressure in

Receiver

Orifice Plate

inserted when

additional

production stream

added

Equipment and Design

Steam used to

scrub Receiver

Water

Orifice Plate

blocked by ice

Block in VCM

vapour line to

Recovery

Water mostly

in other

Recovery

Tank

Operator observation of

difficult venting not addressed

4. Loss of

Plant learning

culture

2. Utilities connected

to Process

Organisation

focus on

Environmental

Improvements

1. Modification Control System

• Development of Electronic system

• Checksheet and reviewer inputs requiring comments

• Authoriser provided details of comments, usually assigned

conditions

• Details of HAZOP and Review actions assigned and

followed up via Actions Review

• Notifications via email

• Pre-commissioning and Post commissioning checks.

• OH&S signoff

1. Poor Mod Control

paper based system

1. HAZOP boundary

not including

existing plant when

additional capacity

added

11 Modification Control System

12 AcciMap of Modification Control Incident

Accident

Sequence

Governance /

Organisational

Regulatory

Outcomes

3500kg VCM LoC

via steam trapsVCM is in Utility

Steam System

Operator

missed

H2O/VCM

interface

Disperses in

atmosphere

or absorbed

in water

spray

Human and

Environmental

Factors Was Operator

present?

Liquid VCM in

Receiver

Reliance on NRV

Cold weather –

autumn night

1. Poor Mod Control

paper based system

Lower SEPP VCM

boundary limits

1. HAZOP boundary

not including

existing plant when

additional capacity

added

3. Poor Regulatory

Oversight

Back pressure in

Receiver

Orifice Plate

inserted when

additional

production stream

added

Equipment and Design

Steam used to

scrub Receiver

Water

Orifice Plate

blocked by ice

Block in VCM

vapour line to

Recovery

Water mostly

in other

Recovery

Tank

Operator observation of

difficult venting not addressed

4. Loss of

Plant learning

culture

2. Utilities connected

to Process

Organisation

focus on

Environmental

Improvements

13

2. Remove Utilities from Process

• Utility steam and air not intended for connection to

process streams

• Generally lower pressure than process units can get

• Process streams need proper pressure and or flow

control – NRV’s fail

• (This was another indicator of loss of integrity

originally designed in).

2. Utilities connected

to Process

Utilities

14 AcciMap of Modification Control Incident

Accident

Sequence

Governance /

Organisational

Regulatory

Outcomes

3500kg VCM LoC

via steam trapsVCM is in Utility

Steam System

Operator

missed

H2O/VCM

interface

Disperses in

atmosphere

or absorbed

in water

spray

Human and

Environmental

Factors Was Operator

present?

Liquid VCM in

Receiver

Reliance on NRV

Cold weather –

autumn night

1. Poor Mod Control

paper based system

Lower SEPP VCM

boundary limits

1. HAZOP boundary

not including

existing plant when

additional capacity

added

3. Poor Regulatory

Oversight

Back pressure in

Receiver

Orifice Plate

inserted when

additional

production stream

added

Equipment and Design

Steam used to

scrub Receiver

Water

Orifice Plate

blocked by ice

Block in VCM

vapour line to

Recovery

Water mostly

in other

Recovery

Tank

Operator observation of

difficult venting not addressed

4. Loss of

Plant learning

culture

2. Utilities connected

to Process

Organisation

focus on

Environmental

Improvements

15

3. Exemplar Safety Case Program

• Recognition needed to do something different

• Would need to do it twice

• Capture corporate knowledge

• Wanted to be a leader

• It was an unknown quantity

• Opportunity to learn and share lessons

Exemplar Safety Case

3. Poor Regulatory

Oversight

16

AcciMap – Modification Control Incident

AcciMap of Modification Control Incident

Accident

Sequence

Governance /

Organisational

Regulatory

Outcomes

3500kg VCM LoC

via steam trapsVCM is in Utility

Steam System

Operator

missed

H2O/VCM

interface

Disperses in

atmosphere

or absorbed

in water

spray

Human and

Environmental

Factors Was Operator

present?

Liquid VCM in

Receiver

Reliance on NRV

Cold weather –

autumn night

1. Poor Mod Control

paper based system

Lower SEPP VCM

boundary limits

1. HAZOP boundary

not including

existing plant when

additional capacity

added

3. Poor Regulatory

Oversight

Back pressure in

Receiver

Orifice Plate

inserted when

additional

production stream

added

Equipment and Design

Steam used to

scrub Receiver

Water

Orifice Plate

blocked by ice

Block in VCM

vapour line to

Recovery

Water mostly

in other

Recovery

Tank

Operator observation of

difficult venting not addressed

4. Loss of

Plant learning

culture

2. Utilities connected

to Process

Organisation

focus on

Environmental

Improvements

17

4. Training and Development

• First Aid

• Emergency

• Chemical Awareness

• Fire Fighting

• Working at Heights

• Permit to Work

• Critical Systems

Training

4. Loss of

Plant learning

culture

• OH&S Legislation

• Natural Gas, Boilers and Water Quality

• Project Management

18

Internal Audit - 2007

• 1 months MoCs 6 months previous

• Automated system functioning well and well accepted.

• Mods allocated appropriate process

• Mods allocated to correct personnel for review

• Implementers frustrated at time to close out:

• Procedures, drawings, training materials

• Less concerned at safety checks and hit sheets

• Changes to personnel were going through formal review processes

• Small number of personnel had not completed training

Internal Audit

19

Summary – Process Safety Control

Process Safety Fundamentals

Process

Safety

Control

Inherent Design Safety

20

What QUESTIONS do you have?

Questions