DEVELOPMENT OF VERY-HIGH-DENSITY LOW-ENRICHED-URANIUM FUELS

Following a hiatus of several years and following its successful devel opment and qualification of 4.8 g U cm(-3) U3Si2-Al dispersion fuel fo r application with low-enriched uranium in research and test reactors, the US Reduced Enrichment for Research and Test Reactors program has embarked on the development of even-higher-density fuels. Our goal is to achieve uranium densities of 8-9 g cm(-3) in aluminum-based dispers ion fuels, Achieving this goal will require the use of high-density, g amma-stabilized uranium alloy powders in conjunction with the most-adv anced fuel fabrication techniques. Key issues being addressed are the reaction of the fuel alloys with aluminum and the irradiation behavior of the fuel alloys and any reaction products. Test irradiations of ca ndidate fuels in very-small (micro) plates are scheduled to begin in t he Advanced Test Reactor during June, 1997. Initial results are expect ed to be available in early 1998. We are performing out-of-reactor stu dies on the phase structure of the candidate alloys on diffusion of th e matrix material into the aluminum. In addition, we are modifying our current dispersion fuel irradiation behavior model to accommodate the new fuels. Several international partners are participating in variou s phases of this work. (C) 1997 Elsevier Science S.A.