Packaging Standards and LoC Process

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Packaging Standards and LoC Process

• Steve Barlow
• Head of Assessments

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LoC and Packaging Standards

• Documentation already provided to CoRWM RD
  group
• Generic Waste Package Specification, N/104
• WPS for HLW and Spent Fuel, N/124
• Guide to LoC Process, WPS/630
• Proposed RD Strategy
• Technical Note on Package Longevity

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Packaging Standards

• Established by Nirex in the late 1980s
• Issued (for ILW) as the Generic Waste Package
  Specification, N/104
• Supported by comprehensive suite of specification
  and guidance material
• Defines package features (dimensions, mass,
  lifting features etc) and characteristics (heat
  output, response to accidents, integrity etc) for
  waste packages to be compatible with transport
  and disposal after a period of interim storage
• Also covers quality management system and data
  records for individual packages
• Waste package specification is largely advisory
  (some criteria are mandatory) hence packaging
  proposals are examined on a case by case basis
  the LoC process

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LoC Process

• Letter of Comfort process established by Nirex in
  late 1980s at suggestion of regulators
• Enabled disposable waste packages to be produced
  avoiding further raw storage of waste e.g.
  Sellafield
• Initially comprised advice from repository
  developer to its shareholders no role in
  regulatory arrangements
• Three stage process Conceptual, Interim, Final,
  linked to permissioning stage-gates.

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Letter of Compliance

• Regulators Position Statement (December 2004)
  and subsequent Guidance to Industry introduced
  formal need for demonstration of disposability
• Assessment through LoC process seen as only
  practical way of achieving this
• In 2005 LoC became Letter of Compliance to make
  it clear that the LoC signified compliance with
  packaging standards derived from repository
  design and safety cases.

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Letter of Compliance 2

• LoC demonstrates that packages have been designed
  against UK packaging standards and are judged to
  be disposable based on information available at
  this time
• not a guarantee
• risk management tool
• It demonstrates that appropriate processes have
  been followed (QMS) and that records on the
  content and characteristics of the waste have
  been generated.
• It is not a substitute for future assessment
  against transport requirements and repository WAC

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Role of LoC Assessments

• Disposability assessment used by SLCs as
  component of Radioactive Waste Management Case
  covering waste retrieval, conditioning, storage
  and transport and disposal
• As we move forward propose to develop a Waste
  Acceptance process whereby SLC demonstrates
  compliance against published acceptance criteria
• Role of disposability assessment reconfirmed in
  December 2007 update guidance from regulators.

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WPS requirements general

• Waste Package
• Limits on activity content to control
• external dose rate
• heat output
• criticality safety
• releases during impact/fire accidents
• Surface contamination
• Venting
• Stackability
• Identification

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WPS requirements related to integrity

• Waste package specification includes criteria
  applicable to the performance of the safety
  barriers - the waste container and the wasteform
• Waste Container
• Provides containment and handling features to
  ensure waste package is suitable for transport
  and emplacement.
• Includes
• Interim surface storage - assumed to be up to 150
  years (precautionary approach)
• Emplacement period - operations assumed to last
  50 years
• Will operations be followed by a period of
  monitored and retrievable storage? Expect this to
  be a key issue for potential communities
  designing disposal facility with flexibility
  regarding timing of closure impacts on waste
  package safety functions
• 500 years as a target lifetime for integrity of
  waste container

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Requirements related to integrity

• Wasteform
• Radioactivity to be immobilised
• Achievement of required physical characteristics
  - minimisation of voidage, heterogeneity,
  strength, impact performance, mass transfer
  characteristics etc
• Achievement of required thermal characteristics -
  thermal conductivity, fire performance etc.
• Elimination of free liquids
• Elimination/neutralisation of hazardous materials
• Control of gas generation
• Wasteform to evolve in a controlled and
  predictable manner absence of cliff-edge effects