Document: NUREG-0800
Document ID: 47c0ffe8-0c76-4d7a-8671-f04b7c8ae803
Document Type: srp
Title: – 15.3.2
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070705.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.3.1
CFR Part: 
CFR Title: 

Content:
LOSS OF FORCED REACTOR COOLANT FLOW INCLUDING TRIP OF PUMP MOTOR AND FLOW CONTROLLER MALFUNCTIONS REVIEW RESPONSIBILITIES Primary - Reactor Systems Branch (RSB)(SRXB)1 Secondary - None I. AREAS OF REVIEW A decrease in reactor coolant flow occurring while the plant is at power could result in a degradation of core heat transfer. An resulting increase in fuel temperature and accompanying 2 fuel damage could then result if specified acceptable fuel damage limits are exceeded during the transient. A number of transients that are expected to occur with moderate frequency and that result in a decrease in forced reactor coolant flow rate are covered by this Standard Review Plan (SRP) section. Each of these transients should be discussed in individual sections of the 3 applicant's safety analysis report (SAR) as suggested by the Standard Format (Ref. 4). Core thermal and hydraulic transients associated with partial and complete loss of reactor coolant flow are evaluated. These include: 1. For boiling water reactors (BWRs), partial and complete recirculation pump trips and malfunctions of the recirculation flow controller to cause decreasing flow. 2. For pressurized water reactors (PWRs), partial and complete reactor coolant pump trips. A partial loss of coolant flow may be caused by a mechanical or electrical failure in a pump motor, a fault in the power supply to the pump motor, a pump motor trip caused by such DRAFT Rev. 2 - April 1996 15.3.1-2 anomalies as over-current or phase imbalance, or a failure within the recirculation flow control network (BWR) resulting in decreasing flow. A complete loss of forced coolant flow may result from the simultaneous loss of electrical power to all pump motors. The review includes the postulated initial core and reactor conditions which are pertinent to the loss of flow transient; the methods of thermal and hydraulic analysis; the postulated sequence of events, including time delays prior to and after protective system actuation;