Document: NRC Regulatory Guide
Document ID: 0d99822b-1af0-41be-a088-75b961301b4f
Document Type: regulatory_guide
Title: Regulatory Guidance on the Alternate Pressurized Thermal Shock Rule + HISTORY - HISTORY 03/2015 – DG-1299 , Proposed Revision 0
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1405/ML14056A011.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.230
CFR Part: 
CFR Title: 

Content:
nt-specific PFM analysis are provided in Section 6.2.2 of NUREG-2163. A discussion of the methodology that was used in performing TWCF calculations for PTS may be found in NUREG-1806, NUREG-1807 (Ref. 8), and NUREG/CR-6854 (Ref. 9). The steps associated with conducting a plant-specific PFM calculation are as follows: i. Perform a Bayesian update of the flaw distribution: • Apply the procedures of Appendix C of NUREG-2163 and obtain revised flaw depth and flaw density parameters (similar to those shown in Table 11 of NUREG-2163). ii. Calculate the TWCF using a PFM computer code (e.g., ORNL/TM-2012/566, Fracture Analysis of Vessels - Oak Ridge (FAVOR) (Ref. 10)): • Run the generalized procedure for generating flaw-related inputs for the FAVOR Code described in NUREG/CR-6817 (Ref. 11) using the revised flaw depth and flaw density parameters. • Develop necessary plant-specific inputs using the guidance in NUREG-1806, NUREG-1807, and NUREG/CR-6854. • Run a plant-specific PFM analysis. • Calculate the TWCF. iii. Compare the plant-specific TWCF to the TWCF limit specified in 10 CFR 50.61a: DG-1299, Page 17 • The evaluation associated with Step I is acceptable if the calculated TWCF is less than or equal to the 1x10-6 events per reactor year limit specified in 10 CFR 50.61a. Step J: If the results of Step I are not acceptable, the licensee should perform a plant-specific assessment for PTS and submit the assessment to the Director of the Office of Nuclear Reactor Regulation for review and approval as required by 10 CFR 50.61a(d)(4). Step K: If the results of Step D or (if applicable) Step H or (if applicable) Step I are satisfactory, the screening criteria contained in Table 1 of 10 CFR 50.61a may be applied to the plant in question. As required by 10 CFR 50.61a(c) , the plant-specific assessment, including explicit details and results, must be submitted to the Director of the Office of Nuclear Reactor Regulation for review and approval in the form of a license