Risk-based analysis of allowed outage times in nuclear power plants

Conference · Fri Nov 01 04:00:00 EST 1985 · Trans. Am. Nucl. Soc.; (United States)

OSTI ID:5770536

Samanta, P K; Wong, S M; Boccio, J L; Vesely, W E

One aspect of technical specifications (TS) in nuclear power plants is the allowed outage time (AOT) of the components in the safety systems. The AOT for a component is the period of time during the plant operation in which the component can be inoperable, i.e., if a component is found failed, it should be repaired within the AOT defined in the TS of the plant; otherwise the plant must be taken to a shutdown state. US Nuclear Regulatory Commission approval for the AOT extension is required for continued operation. Current AOTs defined in the TS were primarily based on engineering judgments, which included judgment on the safety importance of the component and a qualitative consideration of repair time. Risk- and reliability-based methodologies can be utilized to establish AOTs to control and minimize risks due to an AOT. However, the introduction of risk-based insights into the AOT determination process requires the resolution of a number of issues that impact the evaluation. The Procedures for Evaluating Technical Specifications program plan has identified the issues in an evaluation of the Limerick nuclear plant. In this paper, issues that impact AOT evaluations are addressed, and the insights gained toward their resolution are presented.

• Research Organization: Brookhaven National Lab., Upton, NY
• OSTI ID: 5770536
• Report Number(s): CONF-851115-
• Conference Information: Journal Name: Trans. Am. Nucl. Soc.; (United States) Journal Volume: 50
• Country of Publication: United States
• Language: English

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