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:
s part of the PTS re-evaluation effort. The licensee must submit the adjustments made to the volumetric test data to account for NDE-related uncertainties as described in (c)(2) of 10 CFR 50.61a. Step H: The revised flaw distribution results of Step G should be used to compare the revised plant-specific flaw data to Tables 2 and 3 of 10 CFR 50.61a. Step I: If the results of Step H are not acceptable, all flaws should be evaluated for acceptability using one of the following approaches: 1. Preclusion of brittle fracture. Satisfactory demonstration of upper shelf behavior, which precludes brittle fracture, can be based on maintaining temperature above RTNDT + 60 °F using the following steps: i. Compute the irradiated RTNDT for all flaws as follows: DG-1299, Page 16 • Determine the unirradiated value of RTNDT, RTNDT(U), for the material at each flaw location. • Determine the fluence at each flaw location. • Compute ΔT30 for each flaw using Eq. (5) and the fluence at each flaw location. • Compute the flaw-specific value of RTNDT as RTNDT(U) + ΔT30 for each flaw. ii. Assuming a lower bound PTS transient temperature of 75°F, upper shelf behavior is assured if RTNDT + 60 ≤ 75 °F. Therefore, the flaw-specific value of RTNDT should be less than or equal to 15 °F. iii. The evaluation associated with Step I is acceptable if the flaw-specific value of RTNDT is less than or equal to 15°F for all flaws. 2. Calculate the plant-specific TWCF using a plant-specific PFM analysis. A plant-specific PFM analysis to calculate TWCF is complex, and there are many variations of inputs possible for such an analysis. Therefore, specific guidance for plant-specific PFM analysis to calculate TWCF is not included in this regulatory guide. General considerations to include in a plant-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.