The Nuclear Decommissioning Authority

The aim of the Letter of Compliance (LoC) disposability assessment process is to assist nuclear sites in carrying out their clean-up and hazard reduction mission. We check that higher activity wastes will be packaged in a passive and disposable form so that any wastes packaged today should be compliant with future transport and disposability requirements. We cannot guarantee future disposability and we work with sites to review and update our disposability assessments on a periodic basis.  

We provide packaging standards and guidance based on our concepts and safety cases for transport and geological disposal of these wastes. 

• Waste Specifications and Guidance Notes 

Our disposability assessments may identify the need for further information, research and technology development. Where proposed packages are found to be compliant with packaging standards and associated safety and environmental assessments, a Letter of Compliance (LoC) is issued. This indicates, to the best of our knowledge, it would be possible to dispose of the packaged waste in a Geological Disposal Facility.  

• Disposability Assessment Reports

This process is in line with regulatory guidance for higher activity wastes and which requires site licensees to justify waste packaging proposals with a Radioactive Waste Management Case. Our disposability assessment reports are an important input for Radioactive Waste Management Cases, although receipt of a LoC does not provide a safety justification for waste packaging because the relevant regulators still need to satisfy themselves that a packaging proposal is adequate.  

The LoC assessment process is generally applied in stages corresponding to the key development stages of the waste retrieval and packaging project:  

• Pre-conceptual stage when the site is considering different options for retrievals and packaging
• Conceptual stage when the packager is looking to define a preferred conditioning and packaging option
• Interim stage prior to placing "design and build" contracts
• Final stage when the plant is constructed and prior to commencement of operations
• Periodic review to maintain the currency of the LoC and to ensure that it is up to date, typically performed on a 10 yearly cycle.