"This interim staff guidance is being issued to describe to stakeholders methods acceptable to the staff of the U.S. Nuclear Regulatory Commission (NRC) for performing the integrated assessment for external flooding as described in NRC's March 12, 2012, request for information (Ref. 1) issued pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Section 50.54, 'Conditions of licenses,' regarding Recommendation 2.1 of the enclosure to SECY-11-0093, 'Recommendations for Enhancing Reactor Safety in the 21st Century, the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident' (Ref. 2). Among other actions, the March 12, 2012 letter requests that respondents reevaluate flood hazards at each site and compare the reevaluated hazard to the current design basis at the site for each flood mechanism. Addressees are requested to perform an integrated assessment if the current design basis flood hazard does not bound the reevaluated flood hazard for all mechanisms. This ISG [Interim Staff Guidance] will assist operating power reactor respondents and holders of construction permits under 10 CFR Part 50 with performance of the integrated assessment. The guidance provided in this ISG describes methods for use in performing the integrated assessment requested in Enclosure 2 of the March 12, 2012, letter. This guidance is not intended for use in design basis applications or in regulatory activities beyond the scope of performing the integrated assessment."
JLD-ISG-2012-05; Japan Lessons-Learned Directorate-Interim Staff Guidance-2012-05
Nuclear Energy Institute: http://www.nei.org/