Analysis of aging effect on active components at the N reactor

This paper describes the aging analysis methodology developed during the N Reactor Level 1 Probabilistic Risk Assessment to help ensure the validity of a plant-specific component failure rate data base. A graphical technique was used on a system-by-system basis, plotting yearly failures, cumulative yearly failures, and the number of failures per hour for each year the reactor operated over a period of 11 years. Linear curve fits were developed for each data set and the trends of these curves were evaluated and compared. Examples of increasing failure rates attributable to aging were discovered, but engineering and maintenance practices at N Reactor have mitigated any potential consequences