Skip to main content

Radioactive Materials

Volume 461: debated on Friday 15 June 2007

To ask the Secretary of State for Trade and Industry what estimate his Department has made of the total amount of radioactive material unaccounted for from nuclear power stations since their establishment. (141854)

[holding answer 11 June 2007]: Following consultation with the hon. Member, the question will be answered with respect to nuclear material unaccounted for (MUF). MUF is the inventory difference that occurs when the result of a physical inventory of nuclear material is compared with the book inventory. The difference may be negative (an apparent loss) or positive (an apparent gain). MUF is a recognised feature of accounting for nuclear material at processing plants and is caused primarily by the uncertainties inherent in the techniques used to measure nuclear material. An explanation of MUF is available at:

There should be no such MUF for nuclear power stations. Nuclear material in the form of discrete items (fuel elements) is added to the inventory on receipt at the power station site and subtracted from that inventory when fuel is shipped from the site.

Nuclear materials balance figures for UK sites where nuclear material is processed, and hence MUF arises, are published annually. For figures since 1974, I refer the hon. Member to the answer given to the hon. Member for Lewes (Norman Baker) on 15 June 2004, Official Report, column 820W. More recent figures are available at the UK Safeguards Office website at:

There is no evidence to suggest that there have been any real losses or gains of nuclear material.