Document: NUREG-1555
Document ID: f75c60c4-c77d-43bc-9d0f-6a5615e750b4
Document Type: esrp
Title: SEVERE ACCIDENT MITIGATION ALTERNATIVES
Source: NUREG-1555
Source URL: https://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1555/initial/
Revision Date: 2007-10
Chapter: 7
Section ID: 7.3
CFR Part: 
CFR Title: 

Content:
natives. If the applicant used an alternative methodology to a probabilistic risk assessment approach to assess potential SAMAs (e.g., a margins-based approach to evaluate external events initiated by fires or seismic activity), the staff evaluation should be appropriately modified. For example, the synergistic effects of mitigation alternatives that reduce risks for internally initiated events that also provide a benefit for mitigation of externally initiated events should be considered. Alternative benefit-cost approaches are appropriate when a margins method has been used to screen external events. (a) Determine if this set of potential design alternatives and procedural modifications represents a reasonable range of preventive and mitigative alternatives. NUREG-1555 7.3-6 October 1999 (b) Verify that the applicant’s list of potential SAMAs includes a reasonable range of applicable SAMAs derived from consideration of previous analyses and based on insights from the Level 1 and Level 2 portions of the applicant’s probabilistic risk assessment (PRA) or IPE/IPEEE. (3) Evaluate the applicant’s basis for estimating the degree to which various alternatives would reduce risk (expressed as a reduction in core damage frequency or in terms of person-rem averted). In performing its independent assessment, the staff may make bounding assumptions to determine the magnitude of the potential risk reduction for each SAMA. (4) Evaluate whether the applicant’s cost estimates for each SAMA are reasonable and compare the cost estimates with estimates developed elsewhere (e.g., using previous SAMA evaluations or using accepted cost-estimation tools). (5) Evaluate the benefit-cost comparison to determine if it is consistent with the benefit-cost balance criteria and methodology given in NUREG/BR-0058, Rev. 2 (NRC 1997a), and further analyze any SAMAs that are within a decade of the NUREG/BR-0058, Rev. 2, or NUREG/CR-6349 (Mubayi et al. 1995) benefit-cost criteria to ensure