posed by prolonged storage of the plutonium as pits, while minimizing the new security problems arising from the disposition operations themselves. This chapter summarizes our main conclusions and recommendations. (This is also done more briefly in the Executive Summary at the beginning of the report.)

DISPOSITION OPTIONS AND END-POINTS

Options entailing the incorporation of surplus plutonium into fuel that is then irradiated in nuclear reactors (for brevity, "reactor options") can be subdivided by the type of reactor to be used and by the condition of the plutonium at the conclusion of the disposition operation (end-point). Under reactor types, the categories of possible interest are:

  1. electric-power reactors of currently operating commercial types, using fuels of current designs, or evolutionary adaptations of these reactors and fuels (for brevity, "current-reactor types");

  2. electric-power reactors of more advanced varieties ("advanced-reactor types");

  3. current or future naval propulsion reactors;

  4. current or future research reactors; and

  5. new reactors and/or fuels designed specifically for plutonium disposition, or for plutonium disposition in combination with tritium production.

With respect to the end-points of reactor options for plutonium disposition, there is a continuous spectrum of possibilities in terms of residual plutonium quantity, isotopic composition, and quantity of accompanying fission products, but it is useful to distinguish three general classes of outcomes with somewhat different purposes, as follows:

  1. The "spent fuel" outcome is the result of a once-through fuel cycle in which a moderate fraction of the WPu is destroyed and the remainder is embedded in spent fuel that is similar—in bulk, radioactivity, and isotopic composition of the contained plutonium—to the spent fuel that already exists, in considerably larger quantities, from civilian nuclear-power generation. Net destruction of plutonium in this option, taking into account all plutonium isotopes, can range from slightly negative (in that more plutonium is produced from uranium-238 than is consumed from the initial stock of WPu) to as high as 50 percent in advanced light-water reactors and 80 percent in gas-cooled reactors. The purpose of this approach is to create substantial physical, chemical, and radiological barriers to use of the WPu in nuclear explosives by the original owner of the material or by others. This way of doing so would reduce the WPu management problem, at the end-point, to a modest



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement