QUARTERLY PROGRESS REPORT RESEARCH AND DEVELOPMENT PROGRAMS EXECUTED FOR THE DIVISION OF REACTOR DEVELOPMENT. OCTOBER, NOVEMBER, DECEMBER, 1962

摘要

Reducing the average spatial concentration of U 238 in some fuelsnappears important when enriching with plutonium batches containing significant quantities of Pu240 because, with full U238 concentration morenfertility is developed than can be economically supported. Values have beenncalculated for plutonium enrichment of fuels with various uranium spatialnconcentrations in several simulated reactors. The optimum reactors fornburning plutonium of a composition rich in the fertile Pu240 isotope, withnreduced U238 concentration, are those reactors where spatial self shieldingnof the Pu240 effective neutron absorption cross section is minimal. Thencomputed data indicate that plutonium fuels rich in Pu240 are ideally suitednfor high specific power use.