Development of the hot isostatic press manufacturing process for monolithic nuclear fuel

Abstract

The United States Department of Energy, Office of the National uclear Security Administration established the Global Threat eduction Initiative (GTRI) program in the Office of Defense Nuclear onproliferation to reduce and protect vulnerable nuclear and adiological material located at civilian sites worldwide by providng support for countries’ own national programs. An important omponent of the GTRI important is the need to convert research eactors from the use of highly -enriched uranium (HEU) to lownriched uranium (LEU), with less that 20% uranium enrichment. hese efforts result in permanent threat reduction by minimizing nd, to the extent possible, eliminating the need for HEU in civilian pplications. Dispersion fuels made from LEU are inadequate for many highower test reactors (Clark et al., 2006). To achieve the needed oading for high-power test reactors, monolithic U–Mo alloy fuels ave been proposed (Clark et al., 2006), posing the challenge of onding an aluminum cladding to the monolithic fuel foils by proesses other than the roll bonding traditionally used for dispersion uels (Clark et al., 2005, 2006). Clark et al. (2003) proposed that the fuel foils should be prouced by a hot rolling process, followed by bonding the cladding to he fuel foils. To bond the cladding, these authors investigated sevral manufacturing processes, such as: high temperature rolling, ransient liquid phase bonding, diffusion bonding via hot isostatic ressing (HIP), and friction bonding. Of these processes, the HIP onding process produced the most consistent results (Robinson t al., 2009; Clark et al., 2005) and was chosen as the preferred manfacturing method, even though HIPping requires that the material s held under vacuum or reduced atmosphere to prevent the foration of an oxide layer on the material surface.