Risk-based technical specification improvements

Conference · Tue Jan 01 04:00:00 EST 1991 · Transactions of the American Nuclear Society; (United States)

OSTI ID:5777331

Follen, S M; O'Regan, P J ^[1]

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1. Yankee Atomic Electric Co., Bolton, MA (United States)

Technical specification limiting conditions for operation (LCOs) and surveillance test intervals (STIs) strive to ensure that equipment credited in the safety analysis is available and reliable and, thus, able to perform its intended functions should the need arise. Technical specification allowable outage times (AOTs) exist so that plant operation may continue (in the near term) while equipment important to safety is returned to operability. Because of the desire to provide operational flexibility and maximize safety system availability, revisions to technical specifications have been incorporated. Formal PRA methodology and insights have been applied that address both the positive and negative impact of proposed changes. Attributes addressed include the bases for existing requirements, the importance of the equipment in question, the likelihood of applicable scenarios, attendant consequences, and competing effects such as the risk due to mode transitions and plant shutdown. As a result of this effort, existing AOTs have been revised, STIs have been appropriately calibrated, and the application of corrective maintenance has improved. The last is the result of a more carefully though out and less stressful process of restoring equipment to operable status.

• OSTI ID: 5777331
• Report Number(s): CONF-910603--
• Conference Information: Journal Name: Transactions of the American Nuclear Society; (United States) Journal Volume: 63
• Country of Publication: United States
• Language: English

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