Risk-based inservice testing program modifications at Palo Verde nuclear generating station
Arizona Public Service Company (APS) is investigating changes to the Palo Verde Inservice Testing (IST) Program that are intended to result in the reduction of the required test frequency for various valves in the American Society of Mechanical Engineers (ASME) Section XI IST program. The analytical techniques employed to select candidate valves and to demonstrate that these frequency reductions are acceptable are risk based. The results of the Palo Verde probabilistic risk assessment (PRA), updated in June 1994, and the risk significant determination performed as part of the implementation efforts for 10 CFR 50.65 (the maintenance rule) were used to select candidate valves for extended test intervals. Additional component level evaluations were conducted by an `expert panel.` The decision to pursue these changes was facilitated by the ASME Risk-Based Inservice Testing Research Task Force for which Palo Verde is participating as a pilot plant. The NRC`s increasing acceptance of cost beneficial licensing actions and risk-based submittals also provided incentive to seek these changes. Arizona Public Service is pursuing the risk-based IST program modification in order to reduce the unnecessary regulatory burden of the IST program through qualitative and quantitative analysis consistent with maintaining a high level of plant safety. The objectives of this project at Palo Verde are as follows: (1) Apply risk-based technologies to IST components to determine their risk significance (i.e., high or low). (2) Apply a combination of deterministic and risk-based methods to determine appropriate testing requirements for IST components including improvement of testing methods and frequency intervals for high-risk significant components. (3) Apply risk-based technologies to high-risk significant components identified by the {open_quotes}expert panel{close_quotes} and outside of the IST program to determine whether additional testing requirements are appropriate.
- Research Organization:
- American Society of Mechanical Engineers (ASME), New York, NY (United States)
- OSTI ID:
- 402007
- Report Number(s):
- NUREG/CP-0152; CONF-9607103-; ON: TI96013645; TRN: 96:005268-0041
- Resource Relation:
- Conference: 4. NRC/ASME symposium on valve and pump testing in nuclear power plants, Washington, DC (United States), 15-18 Jul 1996; Other Information: PBD: [1996]; Related Information: Is Part Of Proceedings of the 4th NRC/ASME symposium on valve and pump testing; PB: 719 p.
- Country of Publication:
- United States
- Language:
- English
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