Document: NUREG-0800
Document ID: 846ded8e-04ea-4031-8f64-62690ca967b6
Document Type: srp
Title: ANTICIPATED TRANSIENTS WITHOUT SCRAM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070570008.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.8
CFR Part: 
CFR Title: 

Content:
be either consistent with MTC modeling assumptions serving as bases for the Rule or adequately justified. Appendix C to NUREG-0460 discusses the MTC values used by PWR vendors for ATWS analyses before promulgation of the Rule. Enclosure D, Section 5.5, of 49 FR 29036 discusses the probabilities assumed during the Rulemaking of “unfavorable” MTC values resulting in unacceptable plant conditions. 15.8-9 Revision 2 - March 2007 D. Coordinate with the reviewer responsible for instrumentation and controls and verify, to the extent necessary to support the overall review, that instrumentation parameters such as setpoints, tolerances, time delays, ranges, and channel response times specified in the design are acceptable with respect to any critical values assumed in the applicant’s demonstration of the adequacy of required features. E. For events in which the analysis results predict fuel damage and offsite releases, the reviewer will evaluate the predicted extent of fuel damage and resulting offsite consequences with respect to those predicted in the relevant topical reports that the staff has previously accepted, and with acceptance criteria for postulated accidents. 3. For evolutionary plants where 10 CFR 50.62 does not explicitly require a diverse scram system, the applicant may provide a diverse scram system satisfying the design and quality assurance criteria stated in Subsection II or alternatively demonstrate that the consequences of an ATWS event are acceptable. A. Where a diverse scram system is proposed for such plants, the reviewer will verify its adequacy using procedures similar to those described in Section III.1. B. Where the applicant alternatively chooses to demonstrate that the consequences of an ATWS event are acceptable, the reviewer will use procedures similar to those described in Section III.2 above to confirm acceptable consequences without credit for a diverse scram system. 4. When introducing new fuel designs or power-density changes in