PRELIMINARY PROBABILISTIC RISK ASSESSMENT OF ACCIDENT-TOLERANT FUELS ON PWR PERFORMANCE DURING ACCIDENT CONDITIONS

The motivation for exploring the potential development of accident tolerant fuels in PWR to replace existing Zr alloy clad monolithic oxide fuel is outlined. The assessment includes a brief review of core degradation processes under transient conditions and introduces the enhancement of the accident tolerance of PWR by the development of fuels/cladding that can tolerate loss of active cooling in the core and loss of coolant water for a considerably longer time period while maintaining or improving the fuel performance during accident conditions. probabilistic risk assessment are presented that illustrate the impact of these new candidate fuel/cladding materials on the reduction of core damage frequence.