Resolution of Generic Safety Issues: Item B-51: Assessment of Inelastic Analysis Techniques for Equipment and Components ( NUREG-0933, Main Report with Supplements 1–34 )
In the design of nuclear power plants, inelastic response of equipment and components due to severe transients from low probability events is permitted in the ASME Boiler and Pressure Vessel Code, Section III, Subsection NA, Appendix F. Local inelastic response is also permitted for structures under severe impact loads due to low probability events.
Assessment of inelastic analysis techniques applicable to equipment and components is the basic objective of this NUREG-04713 task. Inelastic analysis techniques for structures are under study as a part of USI A-40, "Seismic Design Criteria - Short Term Program."
Since inelastic analysis procedures acceptable under Appendix F of the ASME Boiler and Pressure Vessel Code permit Level D Service Limits and since Level D Service Limits allow large inelastic strains, it is particularly important that properly qualified analysis techniques are used and that their limitations are properly understood.
This item is covered412 in USI A-40, "Seismic Design Criteria Short-Term Program."