UK Plutonium: The Way Forward

In this policy statement we look at future management options for the 112 tonnes of civil held plutonium, including about 28 tonnes of material belonging to overseas customers, currently stored in the UK.

Plutonium is long-lived, toxic and radioactive. It is a material that can be processed for use with nuclear weapons and for these reasons must be handled safely and securely. The future management of this stockpile, largely the by-product of reprocessing spent fuel from UK nuclear power plants, is more complex than was originally anticipated.

The government is reassessing future options for plutonium. Given that the volume has almost doubled since 1997, it is important that decisions on a way forward are made urgently. Since plutonium is fissionable, the government has previously recognised that it provides a potential fuel source for nuclear reactors. However, officially it is not classified as a waste or an asset, but treated as a zero-value asset. Current policy may be missing commercial opportunities and enhanced energy security.

Key recommendations

1. The government should adopt a portfolio of options to address these problematic stocks, rather than seeking a single solution. To this end the Nuclear Decommissioning Authority (NDA) needs to categorise UK plutonium stock and identify the quantities associated with each, so that the most appropriate routes forward can be chosen and best aligned to the condition of the materials.
2. Plutonium of sufficiently high grade should be considered for manufacture into mixed oxide (MOX) fuel in a plant similar to the approach successfully adopted in France, which is simpler than that previously used in the UK.
   
   Lower-grade material should be identified for recycling by use in a fast reactor. This would extract useful energy from the fuel and reduce the volume and toxicity of long-term waste, as well as make a small but useful contribution to UK energy security.
   Investment is needed now by the NDA to demonstrate the potential range of grades that could be used as fast reactor fuel. This, along with fast reactor assessment and development, could prove to be the most economic option.
3. Plutonium of poor quality should be prepared for disposal in a Geological Disposal Facility, via a process that could be expanded if for any reason the fast reactor option failed to materialise.