Transcript Application of Radioactivity and the Law to Contaminated

Application of Radioactivity and the Law
to Contaminated Land and Demolition
Projects
Gareth Walker, BSc, PhD, MRSC
Contents
July 17, 2015

Introduction to legislation

Introduction to contamination land
assessment, and demolition &
decommissioning projects
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Three case studies
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Overview of Legislation
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Main legislation for this presentation

Nuclear Installations Act 1965
 Radioactive Substances Act 1993
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Including Exemption Orders
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Ionising Radiation Regulations 1999
 Environmental Protection Act 1990, Part IIA
 Site Waste Management Plan Regulations
2008
 DEFRA policy on Low Level Waste
Management (2007)
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Why Undertake an Assessment?
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Obligation & Liability management
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Obligated to comply with legislation
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If they fail to comply, are they liable?
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What is the extent of the liability?
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Types of assessments
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Will be focussing on contaminated land and
demolition/decommissioning assessment
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Assessed through
 Contaminated land characterisation
 Risk assessment
 Remediation options and cost assessments
 Waste management
 Materials characterisation
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Case Studies
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Contaminated land assessment
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Sellafield characterisation
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Radiological risk assessment at Hunterston A
Demolition and decommissioning assessment
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Working in partnership with Serco Assurance
Waste management during decommissioning
and demolition at Bradwell
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Considerations Prior to Contaminated Land
Assessment
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Aim of the assessment
Contaminant
Source
Pathway
Receptor
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Leads to a potentially significant pollutant linkage
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Does the pollutant linkage represent an
unacceptable risk?
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Sellafield
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Drilling at Sellafield – Overview
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Installation of boreholes
 Vertical holes (up to 60 m)
 Understanding ground profile (geology)
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Collection of soil and groundwater samples
 Spatial understanding from soil analysis
 Contaminant transport
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Source identification and understanding
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Pollutant linkages (radiological and chemical)
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Conceptual model building
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Characterisation at Sellafield
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Elements of legislation driving this project
 NIA65
 RSA93
 IRR99
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Drilling boreholes into land with unknown
concentrations, isotopes and forms of radioactive
contamination
 Fission products
 Daughter isotopes
 Chemical properties
 Mobility by dissolved phase/colloidal transport
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Drilling at Sellafield
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Summary - Sellafield
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Worker safety paramount – drillers, engineers and
general site staff
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Must maintain nuclear and environmental safety
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Source terms must be defined
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Pathways and receptors must be defined
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Potential liability relating to contaminated land must be
understood
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Radiological Risk Assessment - Overview
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Hunterston A is in the process of decommissioning and
moving towards de-licensing parts of the site
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Driver is to put the site into a care and maintenance
period
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Assessment of risk to people and the environment
arising from land quality issues at Hunterston A
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Through this assessment, understanding the liability
associated with potentially contaminated land
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Radiological Risk Assessment - Overview
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Used land quality data gathered between 2000 and
2008
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Review of data and comparison to current legislation
 NIA65
 RSA93
 EPA90, Part IIA
 Guidance (statutory)
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Establish the extent of risk, if any, to people and the
environment
 Does the site have a liability it needs to address?
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Radiological Risk Assessment – Part IIA
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Contaminated Land Report (CLR) -11 framework
followed to assess risk
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Tiered approach
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Generic qualitative risk assessment (GQRA)
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Phase 1 completed in early 1990s
Characterisation completed
Areas of Potential Concern (APCs) identified
Potentially significant pollutant linkages identified
Conservative approach
Screens each APC through risk assessment
process – further work required?
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Radiological Risk Assessment – Part IIA
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Developed a qualitative risk table
 Based on the MoD Defence Estates methodology,
and input from other consultancies to Defence
Estates
 In consultation with Magnox North
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Assesses pollutant linkage based on
 Magnitude of potential consequence (i.e. Severity)
 Magnitude of probability (i.e. Likelihood)
RISK = SEVERITY X LIKELIHOOD
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Radiological Risk Assessment – Part IIA
DESCRIPTORS FOR SEVERITY OF CONSEQUENCE OF CONTAMINANT
SOURCE-RECEPTOR LINKAGE
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Radiological Risk Assessment – Part IIA
DESCRIPTORS FOR PROBABILITY OF CONSEQUENCE OCCURRING
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Radiological Risk Assessment – Part IIA
DESCRIPTORS OF RISK SIGNIFICANCE
Likelihood:
Severe
Moderate
Potential
consequence:
Mild
Negligible
Very
likely /
certain
Likely
Very High Very High
Unlikely
Very
unlikely
High
Medium
High
High
Medium
Medium
Low
Medium
Medium
Low
Very low
Low
Low
Very low
Trivial
RISK = SEVERITY X LIKELIHOOD
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Radiological Risk Assessment – Part IIA
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Apply to each individual APC
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This will define:
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Is more work required?
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What work is required?
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When can you stop?
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Radiological Risk Assessment - Summary
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Using this risk assessment approach allowed:
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An assessment that is compatible with current law
and guidance
England & Wales – human health only
 Scotland – also, water and ecological environments
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Significance of pollutant linkages to be assessed in
a consistent manner across the NDA land-holding
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Potential contaminated land liability to be better
understood, more readily prioritised and therefore
managed
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Considerations Prior to Demolition and
Decommissioning Assessment
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Legislation and guidance requires quantification of
waste and materials for site-wide Integrated Waste
Strategy (IWS) or Site Waste Management Plan
(SWMP)
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The correct characterisation of items and materials will
form part of an IWS or SWMP
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Location and extent of chemical and radioactive
contamination must be identified
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Waste Classification
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Waste classification and fate
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Intermediate Level Waste – remains at site creating
the waste
Low Level Waste – shipped to the LLWR at Drigg
Very Low Level Waste – hazardous waste landfills
with RSA93 licence
Exempt waste – no regulatory control; free release
All waste removed from the site must be, as far as is
reasonably achievable, re-used or recycled, with
minimum final disposal
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Waste Management During Decommissioning
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Waste Management During Decommissioning
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Waste Management During Decommissioning
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Waste Management During Decommissioning
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Waste Management During Decommissioning
Waste Management During Decommissioning
- Summary
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Context for determination of a site strategy for the
management of decommissioning wastes and items is
determined by Site Waste Management Plan regs
 Previously required an IWS (EGG01)
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Waste management plans should be developed “with
appropriate regulatory and stakeholder involvement”
and should take into account current best practice
 e.g. Nuclear Industry Code of Practice
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Current decommissioning policy for nuclear sites in
under review
 SD:SPUR / SAFESPUR / SAFEGROUNDS /
CoRWM
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Summary
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Obligation and liability management
Legislation – grey areas; overlap; changes
 On-site as opposed to off-site
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Complex sites
 Long histories; many stakeholders
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Pollutant linkages
 Characterise; Assess; Mitigate
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Waste management
 During characterisation
 During remediation
 During demolition & decommissioning
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Acknowledgements
July 17, 2015
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Sellafield contaminated land team
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Hunterston A (Magnox North & Hugh Richards)
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Bradwell (Magnox South)
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Application of Radioactivity and the Law
to Contaminated Land and Demolition
Projects
Gareth Walker, BSc, PhD, MRSC