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:
conditions, accessibility, and practicality of the program. d. Examination procedures and acceptance criteria should be in conformance with the requirements specified in subsection II.3.a of this SRP Section. Technical Rationale:33 The technical rationale for application of the above acceptance criteria to the reactor coolant pump flywheel is discussed in the following paragraphs: 1. GDC 1 and 10 CFR 50.55a require that systems and components be designed, fabricated, erected, constructed, tested, and inspected to quality standards commensurate with the importance of the safety function to be performed. 10 CFR 50.55a also incorporates by reference the applicable editions and addenda of the ASME Boiler and Pressure Vessel Code. Reactor Coolant Pump flywheel failure can result in reduction or loss of forced coolant flow and the effects of resulting missiles could possibly damage the reactor coolant system, the containment, or engineered safety features which provide functions of considerable importance to safety. Application of 10 CFR 50.55a and GDC 1 provides assurance that established standard practices of proven or demonstrated effectiveness are used to assure that failure of the flywheel will not occur, thereby precluding the effects of such a failure commensurate with its importance to safety. 2. GDC 4 requires structures, systems, and components important to safety be protected against the effects of missiles that might result from equipment failures. Regulatory Guide 1.14 describes methods to minimizing the potential for failures of the reactor coolant pump flywheels. During operation at normal speed, a flywheel has sufficient kinetic energy to potentially produce high-energy missiles and excessive vibration of the reactor coolant pump assembly if the flywheel should fail. Overspeed of the pump rotor assembly during a transient increases both the potential for failure and the kinetic energy of the flywheel. The safety consequences of flywheel failure could be