Document: NRC Regulatory Guide
Document ID: c7b1689b-ff17-4083-9fb1-f91b6965ea1a
Document Type: regulatory_guide
Title: Design Basis Floods for Nuclear Power Plants + HISTORY - HISTORY 02/2022 – DG-1290 , Proposed Revision 3 09/2014 – Periodic Review of Revision 2 – Revise 07/1980 – Errata to Revision 2 07/2024 – DG-1290 Revision 1 (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740388.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.59
CFR Part: 
CFR Title: 

Content:
which may adversely affect the flood-producing characteristics of the environs are possible. Examples include construction of a dam upstream or downstream of the plant or, comparably, construc tion of a highway or railroad bridge and embank ment that obstructs the flood flow of a river and con struction of a harbor or deepening of an existing har bor near a coastal or lake site plant. Significantly adverse changes in the runoff or other flood-producing characteristics of the site environs, as they affect the design basis flood, should be iden tified and used as the basis to develop or modify emergency operating procedures, if necessary, to mitigate the effects of the increased flood. 4. Proper utilization of the data and procedures in Appendices B and C will result in PMF peak dis charges and PMS peak stiliwater levels which will in many cases be approved by the NRC staff with no further verification. The staff will continue to accept for review detailed PMF and PMS analyses that result in less conservative estimates than those ob tained by use of Appendices B and C. In addition, previously reviewed and approved detailed PMF and PMS analyses will continue to be acceptable even though the data and procedures in Appendices B and C result in more conservative estimates. D. IMPLEMENTATION The purpose of this section is to provide informa tion to license applicants and licensees regarding the NRC staff's plans for using this regulatory guide. This guide reflects current NRC practice. Therefore, except in those cases in which the appli cant or licensee proposes an acceptable alternative method for complying with specified portions of the Commission's regulations, the methods described herein are being. and will continue to be used in the evaluation of submittals for construction permit ap plications until this guide. is revised as a result of sug gestions from the public or additional'staff review. 1.59-8 APPENDIX A PROBABLE MAXIMUM AND SEISMICALLY INDUCED FLOODS ON