Document: NUREG-0800
Document ID: 0b17303b-e5cc-4091-b22c-056b0c78eb34
Document Type: srp
Title: – 15.3.4
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070707.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 - Reactor Systems Branch (RSBSRXB)1 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 2 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 3 intended to cover both of these accidents. The review is conducted with radioactivity releases and with the includes evaluation of the applicant's postulated initial and long-term core and reactor conditions that are 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 after protective system actuation; the assumed reactions of reactor system components; the functional and operational characteristics of the reactor protection system in terms of how it affects the sequence of events; and all operator actions required to secure and maintain the reactor in a safe condition.4 DRAFT Rev. 3 - April 1996 15.3.3-2 The results of the applicant's analyses are reviewed to assess fuel damage and to ensure that values of pertinent system parameters are within expected ranges for the type and class of reactor under review. Fuel damage is assessed by the methods described in SRP Section 4.2 (Ref. 13). 5 The system parameters that are