The near-term Accident Tolerant Fuel (ATF) concepts consist of minor modifications of the standard UO2-Zr fuel rod materials to provide enhanced accident tolerance. Uranium dioxide fuel with chromia dopant, developed by AREVA, is of interest in view of its enhanced fission gas retention. The predictive capability of the BISON fuel performance code for chromia-doped UO2 fuel is assessed through simulation of the Halden IFA-677.1 fuel rod experiment. A sensitivity analysis is conducted to interpret the deviation of code's predictions from the experimental data.A power ramp test is also modeled with BISON and calculations are compared to the experimental database. Finally, a large-break LOCA (LBLOCA) case is simulated with BISON, leading to an initial assessment of the enhanced safety associated with chromia-doped fuel compared to the standard UO2 fuel in LWRs.
Background:Innovative fuels that provide enhanced safety and maintain economic competitiveness with respect to the current commercial nuclear fleet have drawn worldwide attention [1]. The focus of Accident Tolerant Fuel (ATF) designs is obtaining enhanced accident tolerance while maintaining or improving the fuel performance during normal reactor operation [2]. One of the key performance-limiting factors of conventional UO2 fuel is fission gas release (FGR) at high burnup and/or under accident conditions. During the reactor operation, gaseous fission products Xenon and Krypton are generated in the fuel pellets and partly released into the free volume of the fuel rod. The accumulation of the released fission gases in the rod free volume builds up the rod internal pressure. Meanwhile, the gap conductance degrades due to the poor conductivity of the gaseous fission products relative to the initial Helium fill gas. This leads to higher fuel temperature and higher FGR in turn. FGR is a life-limiting factor for the fuel rod, and is enhanced at extended burnup and during power ramps. In particular, substantial fission gas release occurring on a small time scale has been observed during power ramps [3][4][5]. In addition to this, the contribution of FGR to the rod inner pressure promotes cladding ballooning and burst during a loss-of-coolant accident (LOCA). Also, FGR increases cladding loading and the risk of creep-induced cladding rupture by ballooning during a reactivity-initiated accident (RIA) [6]. For these reasons, it is desirable to retain gaseous fission products within the pellets to limit the detrimental effects of FGR.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.