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Gareth Walker, BSc, PhD, MRSC. Application of Radioactivity and the Law to Contaminated Land and Demolition Projects. Contents. Introduction to legislation Introduction to contamination land assessment, and demolition & decommissioning projects Three case studies. Overview of Legislation.

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Gareth Walker, BSc, PhD, MRSC

Application of Radioactivity and the Law to Contaminated Land and Demolition Projects


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Contents

  • Introduction to legislation

  • Introduction to contamination land assessment, and demolition & decommissioning projects

  • Three case studies


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Overview of Legislation

  • Main legislation for this presentation

    • Nuclear Installations Act 1965

    • Radioactive Substances Act 1993

      • Including Exemption Orders

    • 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?

  • Obligation & Liability management

    • Obligated to comply with legislation

    • If they fail to comply, are they liable?

    • What is the extent of the liability?


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Types of assessments

  • Will be focussing on contaminated land and demolition/decommissioning assessment

  • Assessed through

    • Contaminated land characterisation

    • Risk assessment

    • Remediation options and cost assessments

    • Waste management

    • Materials characterisation


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Case Studies

  • Contaminated land assessment

    • Sellafield characterisation

      • Working in partnership with Serco Assurance

    • Radiological risk assessment at Hunterston A

  • Demolition and decommissioning assessment

    • Waste management during decommissioning and demolition at Bradwell


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Considerations Prior to Contaminated Land Assessment

  • Aim of the assessment

    Contaminant

    Source

    Pathway

    Receptor

    • Leads to a potentially significant pollutant linkage

    • Does the pollutant linkage represent an unacceptable risk?



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Drilling at Sellafield – Overview

  • Installation of boreholes

    • Vertical holes (up to 60 m)

    • Understanding ground profile (geology)

  • Collection of soil and groundwater samples

    • Spatial understanding from soil analysis

    • Contaminant transport

  • Source identification and understanding

  • Pollutant linkages (radiological and chemical)

  • Conceptual model building


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Characterisation at Sellafield

  • Elements of legislation driving this project

    • NIA65

    • RSA93

    • IRR99

  • 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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Summary - Sellafield

  • Worker safety paramount – drillers, engineers and general site staff

  • Must maintain nuclear and environmental safety

  • Source terms must be defined

  • Pathways and receptors must be defined

  • Potential liability relating to contaminated land must be understood


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Radiological Risk Assessment - Overview

  • Hunterston A is in the process of decommissioning and moving towards de-licensing parts of the site

  • Driver is to put the site into a care and maintenance period

  • Assessment of risk to people and the environment arising from land quality issues at Hunterston A

  • Through this assessment, understanding the liability associated with potentially contaminated land


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Radiological Risk Assessment - Overview

  • Used land quality data gathered between 2000 and 2008

  • Review of data and comparison to current legislation

    • NIA65

    • RSA93

    • EPA90, Part IIA

    • Guidance (statutory)

  • 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

  • Contaminated Land Report (CLR) -11 framework followed to assess risk

  • Tiered approach

    • Phase 1 completed in early 1990s

    • Characterisation completed

    • Areas of Potential Concern (APCs) identified

    • Potentially significant pollutant linkages identified

  • Generic qualitative risk assessment (GQRA)

    • Conservative approach

    • Screens each APC through risk assessment process – further work required?


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Radiological Risk Assessment – Part IIA

  • 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

  • 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

RISK = SEVERITY X LIKELIHOOD


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Radiological Risk Assessment – Part IIA

  • Apply to each individual APC

  • This will define:

    • Is more work required?

    • What work is required?

    • When can you stop?


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Radiological Risk Assessment - Summary

  • Using this risk assessment approach allowed:

    • An assessment that is compatible with current law and guidance

      • England & Wales – human health only

      • Scotland – also, water and ecological environments

    • Significance of pollutant linkages to be assessed in a consistent manner across the NDA land-holding

    • 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

  • Legislation and guidance requires quantification of waste and materials for site-wide Integrated Waste Strategy (IWS) or Site Waste Management Plan (SWMP)

  • The correct characterisation of items and materials will form part of an IWS or SWMP

  • Location and extent of chemical and radioactive contamination must be identified


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Waste Classification Assessment

  • Waste classification and fate

    • 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 - Summary Assessment

  • 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)

  • 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

  • Current decommissioning policy for nuclear sites in under review

    • SD:SPUR / SAFESPUR / SAFEGROUNDS / CoRWM


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Summary Assessment

  • Obligation and liability management

    • Legislation – grey areas; overlap; changes

    • On-site as opposed to off-site

  • Complex sites

    • Long histories; many stakeholders

  • Pollutant linkages

    • Characterise; Assess; Mitigate

  • Waste management

    • During characterisation

    • During remediation

    • During demolition & decommissioning


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Acknowledgements Assessment

  • Sellafield contaminated land team

  • Hunterston A (Magnox North & Hugh Richards)

  • Bradwell (Magnox South)


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Gareth Walker, BSc, PhD, MRSC Assessment

Application of Radioactivity and the Law to Contaminated Land and Demolition Projects


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