Document: NUREG-0800
Document ID: 9a49176c-d2fe-4891-93ae-dadad735b22e
Document Type: srp
Title: 15.4.5 STARTUP OF AN INACTIVE LOOP OR RECIRCULATION LOOP AT AN INCORRECT
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350392.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.4.4
CFR Part: 
CFR Title: 

Content:
TEMPERATURE, AND FLOW CONTROLLER MALFUNCTION CAUSING AN INCREASE IN BWR CORE FLOW RATE REVIEW RESPONSIBILITIES Primary - Reactor Systems Branch Secondary - None I. AREAS OF REVIEW A number of transients that may occur with moderate frequency cause 'either increased core flow or introduction of cooler or de-borated water into the core. These transients result in an increase in core reactivity due to decreased mod- erator temperature, moderator boron concentration, or core void fraction. This SRP section is intended to be applicable to all such transients.* Each of these transients should be discussed in individual sections of the applicant's safety analysis report (SAR), as required by the Standard Format (Reference 1). The specific transients (Table 15-1 of Reference 1) evaluated are: 1. Boiling water reactor (BWR): startup of an idle recirculation pump. 2. BWR: flow controller malfunction causing increased recirculation flow. 3. Pressurized water reactor (PWR) with loop isolation valves; startup of a pump in an initially isolated inactive reactor coolant loop where the rate of flow increase is limited by the rate at which the isolation valves open. 4. PWR without loop isolation valves: startup of a pump in an inactive loop. The review of the core flow increase transients considers the sequence of events, the analytical model, the values of parameters used in the analytical model, and the predicted consequences of the transients. The RSB reviewer concentrates on *Continuous boron dilution is considered in another section of the SRP. Rev. 1 - July 1981 USNRC STANDARD REVIEW PLAN Standard review plans are prepared for the guidance of the Office of Nuclear Reactor Regulation staff responsible for the review of applications to construct and operate nuclear power plants. These documents are made available to the public as part of the Commission's policy to Inform the nuclear Industry and the general public of regulatory procedures and policies. Standard review plans are