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

1
Application of Radioactivity and the Law to
Contaminated Land and Demolition Projects

• Gareth Walker, BSc, PhD, MRSC

2
Contents

• Introduction to legislation
• Introduction to contamination land assessment,
  and demolition decommissioning projects
• Three case studies

3
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)

4
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?

5
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

6
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

7
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?

8
Sellafield
9
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

10
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

11
Drilling at Sellafield
12
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

13
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

14
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?

15
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?

16
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

17
Radiological Risk Assessment Part IIA
DESCRIPTORS FOR SEVERITY OF CONSEQUENCE OF
CONTAMINANT SOURCE-RECEPTOR LINKAGE
18
Radiological Risk Assessment Part IIA
DESCRIPTORS FOR PROBABILITY OF CONSEQUENCE
OCCURRING
19
Radiological Risk Assessment Part IIA

• DESCRIPTORS OF Risk significance
• RISK SEVERITY X LIKELIHOOD

Likelihood Very likely / certain Likely Unlikely Very unlikely
Potential consequence Severe Very High Very High High Medium
Potential consequence Moderate High High Medium Low
Potential consequence Mild Medium Medium Low Very low
Potential consequence Negligible Low Low Very low Trivial
Likelihood Very likely / certain Likely Unlikely Very unlikely
Potential consequence Severe Very High Very High High Medium
Potential consequence Moderate High High Medium Low
Potential consequence Mild Medium Medium Low Very low
Potential consequence Negligible Low Low Very low Trivial
20
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?

21
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

22
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

23
Waste Classification

• 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

24
Waste Management During Decommissioning
25
Waste Management During Decommissioning
26
Waste Management During Decommissioning
27
Waste Management During Decommissioning
28
Waste Management During Decommissioning
29
Waste Management During Decommissioning - Summary

• 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
• SDSPUR / SAFESPUR / SAFEGROUNDS / CoRWM

30
Summary

• 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

31
Acknowledgements

• Sellafield contaminated land team
• Hunterston A (Magnox North Hugh Richards)
• Bradwell (Magnox South)

32
Application of Radioactivity and the Law to
Contaminated Land and Demolition Projects

• Gareth Walker, BSc, PhD, MRSC