Document: NRC Regulatory Guide
Document ID: 32d3a378-d575-45ef-9631-a8d6c2b6c30a
Document Type: regulatory_guide
Title: Design-Basis Tornado and Tornado Missiles for Nuclear Power Plants + HISTORY - HISTORY 08/2016 – Periodic Review of Revision 1 – Issues identified for future consideration 08/2011 – Periodic Review of Revision 1 – No issues identified 01/2006 – DG-1143 , Proposed Revision 1 Prior to the issuance of DG-1143, RG 1.76 was entitled "Design-Basis Tornado for Nuclear Power Plants" (Rev. 1)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1620/ML16208A347.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.76
CFR Part: 
CFR Title: 

Content:
ST) is in the middle of a four-year effort to develop new tornado hazards maps for the U.S. and the American Society of Civil Engineers (ASCE) has recently convened a standards committee working group to establish methodologies for estimating tornado wind speeds as well. Preliminary results for these activities indicate that the existing tornado hazard map in RG 1.76, Revision 1, may need to be updated to account for tornado database errors, biases, limitations, and uncertainties. The results of these activities, which will not be available for several years, may provide a basis for updating RG 1.76 once they are published. Any new information will be reviewed upon publication and RG 1.76 assessed for the need of a revision at that time. 2. What is the impact on internal and external stakeholders of not updating the RG for the known issues, in terms of anticipated numbers of licensing and inspection activities over the next several years? The design basis tornado for most operating reactors is based on the more conservative Revision 0 to RG 1.76. Consequently, no technical or regulatory issues are anticipated for most operating reactors. For new reactor designs, the staff anticipates to be reviewing only 1-2 applications in the next several years. If necessary, the NRC staff will deal with these applications on a case-by- case basis. 2 3. What is an estimate of the level of effort needed to address identified issues in terms of full-time equivalent (FTE) and contractor resources? As no technical or regulatory issues were identified for immediate resolution, no resources are required at this time. 4. Based on the answers to the questions above, what is the staff action for this guide (Reviewed with no issues identified, Reviewed with issues identified for future consideration, Revise, or Withdraw)? Reviewed with potential issues identified for future consideration. 5. Provide a conceptual plan and timeframe to address the issues identified during the review. No