Document: NRC Regulatory Guide
Document ID: 3df13dae-14ee-4f25-95b4-1cedf617ae15
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:
TS Rule is applicable to PWR licensees whose construction permits were issued before February 3, 2010, and whose RPVs were designed and fabricated in accordance with Section III of the ASME Code, 1998 Edition or earlier. The purpose of this applicability restriction is that the structural and thermal hydraulic analyses that established the basis for the Alternate PTS Rule embrittlement limits only represented plants constructed before this date. Licensees whose construction permits were issued after February 3, 2010, or with reactor vessels that were not designed and fabricated to the 1998 Edition or earlier of the ASME code must apply for and receive a specific exemption via 10 CFR 50.12 in order to utilize the alternate 10 CFR 50.61a criteria Such applicants for an exemption should demonstrate that the risk-significant factors controlling PTS are adequately addressed by the technical basis calculations developed in support of the Alternate PTS Rule. Position 1 of this document identifies factors to be considered in such an evaluation. 2. Criteria relating to the evaluation of plant-specific surveillance data: The Alternate PTS Rule includes three statistical tests that should be performed on RPV surveillance data to determine whether the surveillance data are sufficiently close to the predictions of the embrittlement trend curve (ETC) used in 10 CFR 50.61a such that the predicted values based on the ETC are valid for use. Position 2 of this document provides guidance by which licensees can assess plant-specific data to the 10 CFR 50.61a ETC using statistical tests. 3. Criteria relating to ISI data and NDE requirements: The Alternate PTS Rule describes a number of tests and conditions on the collection and analysis of inservice inspection (ISI) data and requirements for nondestructive examination (NDE) that are intended to provide reasonable assurance that the distribution of flaws assumed to exist in the PFM calculations that provided the basis for the fracture