Document: NUREG-0800
Document ID: 97b8d603-4b3f-40a3-9dbb-e89b68e654c6
Document Type: srp
Title: ANTICIPATED TRANSIENTS WITHOUT SCRAM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350327.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.8
CFR Part: 
CFR Title: 

Content:
icipated tran- sient without scram events during the interim period before completing the plant modifications that the Commission may find to be necessary, we require that a recirculation pump trip be installed (BWRs) and that an emergency operating procedure for anticipated transient without scram events be developed. Early operator attion as would be specified in the emergency operating procedure and the recirculation pump trip would provide significant protection for those AIWS events that occur (1) as a result of common mode failure of the reactor trip system and some portions of the control rod drive system and (2) at less than full power where the existing Standby Liquid Control-System capacity would be sufficient to limit suppression pool temperature rise to an acceptable level (BWR). Early operator action as would be' specified in the emergency operating procedure would provide significant protection for most ATWS events (Westinghouse)/for all but the initial part of a refueling cycle when the moderator temperature coefficient is least negative (B&W and CE). Our review of the applicant's recirculation pump trip design criteria (BWR) and emergency procedure for anticipated transient without scram 15.8-3 Rev. 1 - July 1981 provides a basis for licensing and interim operation of the _ plant pending the outcome of the Commission rulemaking in ATWS in accordance-with General Design Criteria 10, 15, 26, 27, and 29 of Appendix A to 10 CFR Part 50. The Commission will, by rulemaking, determine any future modifications necessary to resolve the Anticipated Transient Without Scram concerns and the required schedule for implementation of such modifications. REFERENCES 1. Regulatory Staff, "Technical Report on Anticipated Transients Without Scram for-Water Cooled Power Reactors," WASH-1270, U.S. Atomic Energy Commission. 2. Office of Nuclear Reactor Regulation, "Anticipated Transients Without Scram for Light Water Reactors," NUREG-0460, Vols. 1-4, U.S'. Nuclear