Document: NRC Regulatory Guide
Document ID: da2e0703-3488-44b0-b6d0-089aac7cae3d
Document Type: regulatory_guide
Title: Format and Content of Plant-Specific Pressurized Thermal Shock Safety Analysis Reports for Pressurized Water Reactors
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740028.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.154
CFR Part: 
CFR Title: 

Content:
ry overpressure. O Instructions should be based on analyses t h a t include consideration o f system response delay times (e. g. , loop transport time, thermal transport time). O Whether o r not there i s a need f o r cooldown rate l i m i t s f o r periods shorter than 1 hour should be evaluated. O Methods f o r control 1 i n g cooldown rates should be provided. Reference should be made t o these methods with respect t o the dominant PTS r i s k sequences whenever possible. O Guidance should be provided for the operator if cool down rates or i pressure-temperature limits are exceeded. These guidelines should L take into account potential core cooling, environmental release, or containment integrity problems that could exist as a result of respond- ing to the abnormal cooldown rate. These guidelines should leave little doubt as to when PTS concerns are more important than other safety issues and when other safety issues assume primary importance over PTS concerns. It should be emphasized how the guidelines were evaluated and optimized in light of any competing risks that might arise from events other than PTS events to ensure that plant safety is appropriately balanced. O The desired region of operation between the pressure-temperature 1 imi t and the limit determined by avoidance of saturation conditions should be evaluated to determine if it can be revised to minimize total risk due to plant operation from PTS plus non-PTS events. O Instructions for control 1 ing pressure following depressurization transients should be provided. O Instructions should be available for the condition where natural ,circulation is lost and the primary system main circulation pumps are not available. Portions of the above may be provided by incorporation by reference, for example, to the plant-specific Emergency Response Guidelines. However, a sum- mary discussion re1 ati ng the referenced material to the overall subject should be provided. 8.3 Inservice Inspection and Nondestructive