Third quarter of 2002

UK civilian plutonium stockpile still on the uphill

WISE-Paris, 27 August 2002

[Posted 28/08/2002]

On 24 July 2002, the United Kingdom published the annual figures concerning its civilian plutonium stocks. (1) This publication corresponds to the yearly communications of the IAEA Member States via their permanent missions, regarding the management of plutonium. The UK's latest figures, as of December 2001, show an increase of the separated civilian plutonium stockpile of 4.3 t.

Although they correspond to a 5.5% growth of the stockpile in 2001, the figures translate a slight slow down in the pace of plutonium accumulation. In fact, the UK's civilian plutonium stockpile increased by one-third in only six years, from 54.8 t in 1996 to 82.4 t as of the end of 2001 (with a rate of 3.4 t to 9 t per year), reaching the world's highest level for this type of material. More than half of this 27.6 t increase, i.e. 14.3 t, was produced by reprocessing foreign spent fuel, while 13.3 t result from the UK's spent fuel reprocessing.

Only a very small part of the separated plutonium has been re-used, in the form of mixed-oxide fuel (MOX). Although there is currently no plan to use MOX fuel in British nuclear power plants, the UK has sought to develop MOX fabrication as a service provided to foreign clients, within the framework of its reprocessing industry.

Until 3 October 2001, the date the Government authorized operating of the Sellafield MOX Plant (SMP), with a capacity of 120 tHM/yr, BNFL had operated a small pilot plant, the MOX Demonstration Facility (MDF), with a capacity of 8 tHM/yr. The MDF ran between 1993 and 1999 and produced only around 18 t of MOX for foreign clients, corresponding to the re-use of not more than some 1 t of separated plutonium. The MDF was stopped in the late 1999 after the discovery of a large-scale quality-control scandal, in the MOX fabrication program for Japan.

The new SMP should in theory help to reduce the stockpile of foreign separated plutonium, which amounted to 17.1 t, as of 31 December 2001. But the order book is far from being complete, and the plant has been the target of strong criticism. On 9 November 2001, Ireland brought the case to the Hamburg-based International Tribunal for the Law of the Sea, to prevent the UK from operating SMP. (2)

The use of the remaining 65.3 t, representing the UK's share of civilian plutonium, as of 31 December 2001, has yet to be determined. After a 3.8 t increase in 2001, and taking into account the ongoing reprocessing, the stockpile will most likely continue to grow in the coming years. But its economic value has now officially fallen to zero. According to a statement made on October 22nd 2001 by the then Secretary of State for Trade and Industry, Mr. Wilson, in an answer to a Parliamentary question, the BNFL owned stocks of separated plutonium and reprocessed uranium "were given a nil value" in the National Asset Register.


  1. See
  2. See " Irish Government Presents WISE-Paris Report as "Evidence" in Case Against the UK Over the Sellafield MOX Plant ", WISE-Paris, 23 November 2001,

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