Document: NUREG-0800
Document ID: a62e5e30-e809-4a7d-967f-f6b3c6726d91
Document Type: srp
Title: - 15.3.4
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550012.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.3.3
CFR Part: 
CFR Title: 

Content:
REACTOR COOLANT PUMP ROTOR SEIZURE AND REACTOR COOLANT PUMP SHAFT BREAK REVIEW RESPONSIBILITIES: Primary - Organization responsible for review of transient and accident analyses for PWRs/BWRs Secondary - None I. AREAS OF REVIEW The events postulated are an instantaneous seizure of the rotor or break of the shaft of a reactor coolant pump (RCP) in a pressurized water reactor (PWR) or recirculation pump in a boiling water reactor (BWR). Flow through the affected loop is rapidly reduced, leading to a reactor and turbine trip. The sudden decrease in core coolant flow while the reactor is at power results in a degradation of core heat transfer which could result in fuel damage. The initial rate of reduction of coolant flow is greater for the rotor seizure event. However, the shaft break event permits a greater reverse flow through the affected loop later during the transient and, therefore, results in a lower core flow rate at that time. This Standard Review Plan (SRP) section is intended to cover both of these accidents. 1. RCP Shaft Seizure or Shaft Break Accidents The review includes evaluation of the applicant's postulated initial and long-term core and reactor conditions pertinent to the rotor seizure or broken shaft events; the methods of thermal and hydraulic analysis; the postulated sequence of events, including time delays prior to and