Nuclear Materials

This theme addresses the challenges of storage and disposition of the plutonium arising from the reprocessing of spent fuel.

The UK’s civil inventory of nuclear materials contains significant stocks of separated Pu from the reprocessing of Magnox and AGR spent fuels. The preferred option for the 140 t of Pu is re-use as mixed oxide fuel, although 5% is not suitable for re-use and is recommended for direct disposal. However, it will take >15 years to implement re-use, requiring that the Pu be kept in its current state for that period, i.e. as PuO2 powder in inert steel storage cans at Sellafield.

The aim of the research is to provide technical underpinning to ongoing option development for the UK civil Pu stockpile.

Theme Objectives:

  • For interim storage, to understand how the surface structure and properties of pristine and radiation damaged PuO2 change with time in the absence and presence of water
  • For disposition, to understand the mechanisms of incorporation of Pu into ceramic and glass-ceramic wasteforms, as well as the effect on these of self-induced radiation damage

Work Packages:

  • Surface Chemistry of PuO2 Under Conditions Relevant to Interim Storage
  • Plutonium Immobilisation in Advanced Ceramic Wasteforms