Elevated-temperature structural design evaluation issues in LMFBR licensing

This paper describes elevated-temperature structural design issues and concerns identified by the NRC licensing review of the Clinch River Breeder Reactor Plant for a construction permit. Major issues concern weldment evaluation, notch weakening, steam generator tubesheet evaluation, and the use of “average” rather than “minimum” material properties in inelastic analysis. Other questions concern seismic effects, elastic follow-up, creep fatigue evaluation, plastic strain concentration, and transition welds. All of the issues were resolved but several required CRBRP Project commitment to perform additional confirmatory programs.