Plutonium management policy in the United Kingdom: The need for a dual track strategy

The United Kingdom holds the largest stockpile of separated civil plutonium in the world, projected to reach 140 t, at the end of this decade, when reprocessing operations are complete. UK Government policy is that this material should be reused as MOX fuel in Light Water Reactors. This policy is re-examined in the light of recent experience of the US plutonium disposition programme, in which the MOX Fuel Fabrication Facility is now considered to be potentially unaffordable. Problematic aspects of US programme, relevant to the UK scenario, are reviewed, to understand the possible impact on UK policy. Based on the US experience and inherent uncertainty regarding the capital and operational costs of MOX fuel fabrication and plutonium immobilisation facilities, and the associated technical risks, it is concluded that the UK policy should explicitly adopt a dual track strategy to plutonium management, with commitment that: any remaining plutonium which is not converted into MOX fuel, or otherwise reused, will be immobilised and treated as waste for disposal. This will also ensure that the UK is positioned and prepared to take forward an immobilisation and disposal programme for the plutonium stockpile, should reuse as MOX fuel not prove an economic or viable option. - Highlights: • Policy and technology developments in US plutonium disposition programme are analysed. • The vulnerabilities of the UK policy for plutonium reuse as MOX fuel are assessed. • Adoption of dual-track approach to management of UK plutonium is recommended.