Accident source terms for light-water nuclear power plants

摘要: This paper presents a discussion of current U.S. Nuclear Regulatory Commission (NRC) activities regarding the proposed revision accident source terms for light-water nuclear power plants, particularly since issuance draft revised in July 1992. The NRC's reactor site criteria require that an fission product release within containment, or [open quotes]source term,[close quotes] be postulated to occur and its radiological dose consequences evaluated. term, derived from 1962 report 2 TID-14844, postulates instantaneous appearance containment 10% core inventory noble gases, 50% iodine (with half this assumed plate out very rapidly on interior surfaces), remaining products. term has also been used evaluate other important plant performance requirements, such as control room habitability, postaccident access, sampling equipment qualification, consequently played role licensing. Aspects have long recognized being inconsistent with realistic understanding severe behavior. Because NRC review advanced designs showed need more mitigation capability,more » it became clear should updated.« less