Radiation protection of the environment – an introduction
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Transcript of Radiation protection of the environment – an introduction
Brenda Howard (CEH)
Radiation protection of the environment – an introduction
www.ceh.ac.uk/PROTECT
Outline Historical perspective – previous
ICRP guidance Why this has changed - prime
motivations International initiatives at the EC,
IAEA, ICRP and UNSCEAR The situations in which
assessments may be used Radiation protection of the
environment in the UK Tiered assessments Comparison with chemicals Expectations
Credit: John Foster / US Fish & Wildlife Service
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International responsibilities ICRP – radiation protection guidelines IAEA – unique statutory responsibilities within
UN for establishing standards of radiation safety (and by
implication also for environmental protection) Providing for the application of the standards at the
request of any state UNSCEAR – to estimate sources and effects of
exposure to ionising radiation and to report its estimates to the UN General Assembly
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Key international drivers
IAEA
ICRPUNSCEAR
Member States
EU
Historical perspective – previous ICRP guidance
“The Commission believes that the standard of environmental control needed to protect man to the degree currently thought desirable will ensure that other species are not put at risk. Occasionally, individual members of non-human species might be harmed, but not to the extent of endangering whole species or creating imbalance between species. At the present time, the Commission concerns itself with mankind’s environment only with regard to the transfer of radionuclides through the environment, since this directly affects the radiological protection of man”
ICRP, 1991, Para. 16
CEH photographyCEH photography
History
Focus on worker/most exposed individuals Incomplete ecological information Limited evidence provided to support
statement (in the context of the environment)
Credit: John Sarvis / US Fish & Wildlife Service
History
Focus on worker/most exposed individuals Incomplete ecological information Limited evidence provided to support
statement Changing attitudes
Late 1990s tools and techniques available Recognition of environmental risks (e.g. Rio) Conservation and protection drivers
History
Focus on worker/most exposed individuals Incomplete ecological information No evidence provided to support statement Changing attitudes
Late 1990s tools and techniques available Recognition of environmental risks (e.g. Rio) Conservation and protection drivers
Counter arguments
History
Focus on worker/most exposed individuals Incomplete ecological information No evidence provided to support statement Changing attitudes
Late 1990s tools and techniques available Recognition of environmental risks (e.g. Rio) Conservation and protection drivers
Counter argumentsThe need to explicitly
demonstrate no im
pact…
History
ICRP Task group set up in 2000 New ground ICRP strongly influenced by development of
radiological protection of humans Others working on environmental issues
ICRP Publication 91 (2003) A framework for assessing the impact of ionising
radiation on non-human species
History
New Committee (5) setup in 2005 Take a structured approach Address key ‘conceptual gap’ Develop the framework Parallel approach used for humans Input into new Recommendations in
2007 Appointed for second term in 2009
Credit: Art Weber / US Fish & Wildlife Service
2007 Recommendations
ICRP (Publication 103) recognised Need for advice and guidance Lack of consistency at an international level More proactive approach needed Complex nature of environmental protection Need to develop a clearer framework
Assess exposure – dose – effect relationships Pragmatic approach, which can develop No “dose limits”
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ICRP Exposure Situations
Planned – current activities, not historic (yrs of discharge) and new nuclear sites and
U mines etc Mostly for planned NPP and waste repositories (current or prospective
discharges)
Existing – exposure to natural radiation sources and contamination of areas by residual radioactive material
Past activities that were never subject to regulatory control or were not regulated according to present requirements;
An emergency, after the emergency exposure situation has been declared ended
Residues from past activities for which their is no longer legally accountability
Aim, relevance - used in USA for previously contaminated sites
Emergency – eg accidents, malevolent acts Low priority in acute phase
History
In response, IAEA develop Plan of Activities on Radiation Protection of Environment (approved by Board of Governors Sept 2005)
The revision of the IAEA Basic Safety Standards does include the drafting of a requirement on radiation protection of the environment in line with Principle 7 of the Safety Fundamentals.
Stockholm conference 2003: “the time is ripe for launching a number of international initiatives to consolidate the present approach to controlling radioactive discharges to the environment by taking explicit account of the protection of species other than humans”
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Other drivers
National legislation National interpretation of
international legislation Various bodies – need to explicitly
demonstrate/why diff to chemicals IUR promoted need for an approach
not based on humans OECD-NEA has highlighted the
need for radiological assessment of non-human biota and supported tiered assessment approach
Credit: Mike Lockhart / US Fish & Wildlife Service
Credit: Art Sowls / US Fish & Wildlife Service
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Other International initiatives: IAEA
IAEA Standards
Action plan Biota Co-ordination
Group Basic Safety Standards
Approaches Environmental Modelling
for Radiation Safety Application
Technical cooperation on wildlife regulation RER 7005
CEH photograph
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IAEA BSS – draft May 2010Protection of the environment
“1.26. In a global and long term perspective, protection of people and the environment against radiation risks associated with the operation of facilities and the conduct of activities — risks that may transcend national borders and may persist for long periods of time — is important to achieving equitable and sustainable development. The aim of radiation protection of the environment is to protect ecosystems against radiation risks. The system of protection and safety in these Standards generally provides appropriate protection of ecosystems in the human environment against harmful effects of radiation exposure. Nevertheless, international trends in this field show an increasing awareness of the vulnerability of the environment. Trends also indicate the need to be able to demonstrate (rather than to assume) that the environment is protected against effects of industrial pollutants, including radionuclides, in a wider range of environmental situations, irrespective of any human connection with them. This is normally accomplished through an environmental assessment, which identifies the target(s), defines the appropriate criteria for protection, assesses the impacts and compares the results of the available protection options. The methods and criteria for these radiological assessments are being developed and will continue to evolve. Radiation impacts within a particular environment constitute only one type of impact and in most cases, may not be the dominant impact of a particular facility or activity. Further, the assessment of impacts on the environment should be viewed in an integrated manner with the other features of the system of protection to establish the conditions applicable to a particular source. These Standards are designed to clearly identify protection of the environment as an issue to be assessed, while leaving flexibility to incorporate the results into the appropriate decision making processes.”
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UNSCEAR
United Nations Scientific Committee on the Effects of Atomic Radiation
Established in 1955 UN Scientific Committee reports to General Assembly Assesses global levels and effects of ionizing
radiation Provides scientific basis for radiation protection Governments and organisations rely on Committee's
estimates as the scientific basis for evaluating radiation risk and establishing protective measures
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UNSCEAR - environment
Report on “Effects of radiation on the Environment” in 1996
Limited available data Review of data, including Chernobyl Based largely on acute data Effects difficult to estimate due to long term
recovery, compensatory behaviour and
confounding environmental factors
New report imminent
UNSCEAR 1996
Acute doses
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EC Euratom Basic Safety Standards
New BSS outline Title X: Protection of the Environment
Euratom projects FASSET ERICA PROTECT FP7 - Network ??
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Draft European Basic Safety Standards Directive – Version 24 February 2010
TITLE X: PROTECTION OF THE ENVIRONMENT
Article 102Member States shall include, in the legal framework for radiation protection, provision for the radiation
protection of non-human species in the environment; this legal framework shall introduce environmental criteria aiming at the protection of populations of vulnerable or representative non-human species with regard to their significance as part of the ecosystem. Where appropriate, practices shall be identified for which regulatory control is warranted to implement the requirements in this legal framework and take account of appropriate environmental assessment criteria.
Article 103
Member States' competent authorities, when establishing authorised limits on discharges of radioactive effluents, in accordance with Article 91 paragraph 2, shall also ensure adequate protection of non-human species; for this purpose a generic screening assessment may be conducted to provide reliance that the environmental criteria are met.
Article 104
Member States shall require undertakings to take appropriate technical measures with the aim to avoid that in the event of an accidental release there will be significant environmental damage, or to mitigate the extent of such consequences.
Article 105
While establishing environmental monitoring programmes, or requiring such programmes to be carried out, Member States' competent authorities shall include representative nonhuman species, if necessary, in addition to such environmental media which constitute a pathway of exposure to members of the public.
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UK Legislative framework Europe: Habitats and Birds
Directives On the conservation of natural
habitats and of wild flora and fauna
UK: Conservation (Natural Habitats) regulations 1994 Implements the Habitats
Directive in the UK. Requires steps to maintain and restoration to favourable conservation status of habitats and species of Community level interest
Credit: John Sarvis / US Fish & Wildlife Service
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The Environment Agency’s role
Has a duty to comply with the EU Habitats and Birds Directives
EA obligations to review: Existing authorisations, consents, licences and
permissions for chemicals All requests for variations to existing or new applications Ensure that no Agency-authorised activity or permission
results in an adverse effect, either directly or indirectly on the integrity of identified European sites (Natura 2000 sites)
The driver is from conservation perspective not radiological protection
Credit: Eric Engbretson / US Fish & Wildlife Service
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The Environment Agency’s role
Given the requirement to assess the impacts of consent and authorisations affecting Natura 2000 sites: The EA took the view , based on legal advice
and with the support of English Nature (statutory consultee), that these assessments should include radiation
(now also SEPA)
Credit: Sue Matthews / US Fish & Wildlife Service
Credit: US Fish & Wildlife Service division of public affairs
Tiered Assessments
Many approaches use a tiered assessment structure (in common with other areas of risk assessments) simple initial screening through to more refined
assessments Also referred to as:
staged or graded approaches
Credit: Dave Menke / US Fish & Wildlife Service
Credit: Greg Wilker / US Fish & Wildlife Service
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ERICA flow chart
ERICA Integrated Approach
Concentration screening value
Dose rate screening value
Detailed analysis and evaluation of data. Interaction and supplementation with all relevant databases
Extrapolation (e.g. population, ecosystem)
Management Assessment Tool CharacterisationManagement Assessment Tool Characterisation
Tier 3
Site-specific
Probabilistic analysis
Tier 2
Tier 1
Sta
keho
lder
Invo
lvem
ent
Issues
and
options
Plan
Evaluation of assessment
April 2006
Problem formulation
Exit
Exit
Tiered approach
Environmental and health protection
Conservatism
Resources
TIER 1Risk screening
TIER 2Generic quantitative
TIER 3Detailed Quantitative
Data needs
Tiered approach
Environmental and health protection
Conservatism
Resources
TIER 1Risk screening
TIER 2Generic quantitative
TIER 3Detailed Quantitative
Data needs
The level of detail in a risk assessment should be proportio
nate
with the nature and complexity of the risk being addressed and
consistent with decision-making needs
Direct toxicity in soil and water: the assessment of toxicity thresholds for plants, invertebrates and microbial processes
Higher organism health: comparison withConcentration in food eaten Ingested amount per unit liveweight of receptor speciesConcentration in organs of species compared to a risk quotient
Human health: quantifying exposure to contaminants and assessing acceptable intake values
Approaches for chemicals in the environment
Soil solids Soil water
M-DOM
M-X
M-soil
M output = [M]aq x runoff
M inputg ha-1 a-1
H+
Mz+
Maq
Soil bioavailability
Critical Loads
The critical load is the rate of deposition of a metal from the atmosphere, which at steady
state, leads to the metal concentration in soils or water reaching a threshold for
adverse effects (the critical limit)
Credit: Calexico New River Committee (CNRC)
Critical Loads for LeadLead
0 - 200
200 - 400
400 - 800
>800
Lead
0 - 200
200 - 400
400 - 800
>800
0 - 200
200 - 400
400 - 800
>800
no exceedance
0 - 10
1 - 20
>20
no exceedance
0 - 10
1 - 20
>20
Critical Load for Pb (g ha-1 y-1)Exceedance of Critical Load for Pb in Managed Broadleaf Woodland
(ratio)
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Why are we giving these courses?
Assessments are being done – little formal training available
We are being asked for advice on use of assessment tools
The tools are only recently developed and there are various complexities and assumptions which need to be understood
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Course participants expectations
Fundamentals of radiation protection of the environment
Background to development of the ERICA tool To learn how to use the ERICA Tool
Some asking for detailed understanding limitations
Comparison with, and knowledge of, other tools Transfer in the environment Dose impacts
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Elements of assessment
Media concentration
Release
Dose rate
Risk
Dispersion model
Transfer model
Dosimetry model(internal exposure)
Wholebody activity concentrationsDosimetry model
(external exposure)
Effects understanding/ numerical benchmark