KEEPING A WORLD-WIDE MEASUREMENT SYSTEMFOR PLUTONIUM IN PLACE FOR THE NEXT 20 YEARS

摘要

The measurement of amounts of plutonium is recognised as one of the most importantrntasks in fissile material control. The task requires that both the element amounts andrnisotopic abundances be measured with uncertainties as low as possible: an onerous taskrnfor measurement laboratories.rnA big step forward in keeping the measurement structure intact has been the productionrnof the new CRM126A Pu metal standard from NBL and the CEA/CETAMA MP3 metalrnstandard, presently under development. The accurate measurement of Pu amounts can berntraced to these and earlier standards in laboratories all round the world.rnBoth in the USA and in France it was recognised that the production of these standardsrnwas much more difficult (and therefore expensive) than planned and that often it wasrndifficult to find the necessary expertise to produce, handle and analyse the materials. Thernquestion therefore arises if it will be possible to reproduce this work in the future, givenrnthe present universal reduction of nuclear work in this area. Moreover, the difficulties inrntransporting plutonium – sometimes extremely difficult across national borders, but alsornbecoming more difficult within individual countries – add to the problems of having Purnstandards known to be traceable to one of these primary materials.rnPossible solutions need to be considered now. These solutions should include thernpossibility of local preparation of materials, optimised methods of certification and newrnmethods of analysis. We should also consider taking active steps to restrict usage of suchrnmaterials except where they are absolutely needed.