Us regulatory requirements for blast effects from accidental explosions

Abstract Procedures and criteria acceptable to the USNRC for verifying the adequacy of nuclear power plant structures, systems and components to resist the effects of accidental explosions outside the plant are presented. A method of computing the probability of an accidental explosion is also given. The relative importance of blast generated missiles, wind, overpressure and ground shock is treated. The inherent strength of Nuclear Power Plants to resist blast effects due to imposed design requirements for other extreme environmetal loads, such as tornadoes, is considered. Shortcomings in the previous practice of comparing air blasts with tornadoes are outlined. Load combinations as well as allowable limits under blast effects are treated. Differences between USNRC requirements and those presented in Appendix C to the ACI-349 Code, ‘Code Requirements for Nuclear Safety Related Concrete Structures’, are outlined and evaluated.