Document: NUREG-0800
Document ID: 8d8c874b-f1ef-4884-8228-654f526c0ce4
Document Type: srp
Title: PUMP FLYWHEEL INTEGRITY (PWR)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070445.pdf
Revision Date: 2023-06
Chapter: 5
Section ID: 5.4.1.1
CFR Part: 
CFR Title: 

Content:
REVIEW RESPONSIBILITIES Primary - Materials Engineering Branch (MTEB)Materials and Chemical Engineering Branch (EMCB) 1 Secondary - None I. AREAS OF REVIEW General Design Criterion 4 (Ref. 1) requires that structures, systems, and components of nuclear 2 power plants important to safety be protected against the effects of missiles that might result from equipment failures. Because flywheels have large masses and rotate at speeds of 900 rpm or 1200 rpm during normal reactor operation, a loss of flywheel integrity could result in high energy missiles and excessive vibration of the reactor coolant pump assembly. The safety consequences could be significant because of possible damage to the reactor coolant system, the containment, or the engineered safety features. General Design Criterion 1 (Ref. 1) and 10 CFR Part 50, 50.55a(a)(1) require that structures, 3 4 systems, and components important to safety shall be designed, fabricated, erected and tested to quality standards which shall be identified and evaluated to determine their adequacy to assure a quality product in keeping with the required safety function. DRAFT Rev. 2 - April 1996 5.4.1.1-2 The following areas relating to reactor coolant pump flywheel integrity are reviewed by MTEBEMCB : 5 1. Materials Selection Reactor coolant pump flywheels are of a simple geometric shape, and are made of ductile material. Their quality can be closely controlled and their service conditions are not severe; therefore, the use of suitable material, coupled with adequate design and inservice inspection can provide a sufficiently small probability of a flywheel failure that the consequences of failure need not be protected against. Information in the applicant's safety analysis report (SAR) on materials selection and the procedures used to minimize flaws and improve mechanical properties is reviewed to establish that sufficient information is provided to permit an evaluation of the adequacy of the flywheel materials. 2. Fracture