A method for monitoring and evaluating thermal transient fatigue usage in a nuclear power plant

This paper describes a simplified method for monitoring and evaluating thermal transient fatigue usage in nuclear power plants. This methodology is being implemented at the San Onofre Nuclear Generating Station Units 2 and 3. The transient monitoring and evaluation method described herein has been developed to be consistent with the San Onofre Design Basis. This fatigue usage evaluation technique also includes consideration of partial transient cycles as a percentage of design transients. The monitoring portion of this method satisfies plant Technical Specification and record keeping requirements for both present regulatory compliance and longer term plant life extension. The emphasis in this paper is on the methodology developed to relate to the effect of partial transient cycles to the more severe design basis transients