Motor-operated globe valve performance in a liquid sodium environment
This study investigates motor-operated globe valve (MOV) performance in a liquid sodium environment as reported to the Centralized Reliability Data Organization (CREDO) from site representatives at several liquid metal reactors and liquid metal test facilities. The CREDO data base contains engineering histories for 179 motor-operated glove valves. Thirty nine failures have been documented for these components in over 8.7 million hours of operation. The most common MOV events were anomalies with the limit and torque switches, although human initiated problems were also frequent causes of failures. The failure data suggest that an improved preventive maintenance program with a higher frequency of inspection of the limit and torque switches should increase MOV availability and reliability. The event rate for all failure modes was computed as 4.47 events per 10{sup 8} operating hours by assuming a Poisson distribution of failure over valve operating time. The 5% and 95% confidence limits based on a chi-squared ({chi}{sup 2}) probability distribution function were computed as 3.36 and 5.83 events per 10{sup 6} operating hours, respectively. The operating performance of these liquid metal MOVs was compared to similar data for MOVs in commercial light water reactors and was found to exhibit similar failure rates.
- Research Organization:
- Oak Ridge National Lab., Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 10149713
- Report Number(s):
- CONF-920818-2; ON: DE92014456
- Resource Relation:
- Conference: Bi-annual nuclear energy meeting of the American Nuclear Society (ANS) and the American Society of Mechanical Engineers (ASME),San Diego, CA (United States),23-26 Aug 1992; Other Information: PBD: [1992]
- Country of Publication:
- United States
- Language:
- English
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