LEU fuel development progress and programs, BWXT Technologies, Inc

BWXT believes that the best method to developing refueling solutions is to completely understand the associated challenges and related requirements. To achieve the maximum fuel densities needed to convert the remaining HEU plate research reactors in the United States, a solid fuel core must be utilized. DOE has mandated that this program be accelerated. During this past year, BWXT has been investigating techniques for fabricating Monolithic (solid core) fuel plates using U-xMo. In cooperation with Argonne National Laboratory, BWXT is preparing a parallel development program utilizing Hot Isostatic Press (HIP) technology, as well as other techniques, to produce a solid fuel core/plate. Diffusion-bonding aluminum presents the challenge. Aluminum rapidly oxidizes and generally requires physically manipulating (hot rolling) the material to break up oxides and allow grain growth. The standard method for fabricating research reactor fuel plates is hot roll bonding. However, hot rolling the differential alloys, aluminum and solid U-xMo foil, has had limited success. The temperature required, above 53 deg. C, breaks down the aluminum alloy mandating a solution anneal of the aluminum plate. This is inefficient and has had little success. Extreme processes such as vacuum press and HIP are currently being developed. These methods, showing the most promise, will be discussed herein. (author)