- Volume 36 Issue 4
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An Investigation of Turbine Blade Ejection Frequency Considering Common Cause Failure in Nuclear Power Plants
공통원인고장을 고려한 원전 터빈블레이드 비산빈도계산
- Oh, Ji-Yong (Central Research Institute, Korea Hydro & Nuclear Power Co., Ltd.) ;
- Chi, Moon-Goo (Central Research Institute, Korea Hydro & Nuclear Power Co., Ltd.) ;
- Hwang, Seok-Won (Central Research Institute, Korea Hydro & Nuclear Power Co., Ltd.)
- Received : 2011.02.21
- Accepted : 2012.02.08
- Published : 2012.04.01
The objective of this research is to examine the probabilistic approach to evaluating turbine ejection frequency considering common-cause failure. This paper identifies basic turbine ejection mechanisms under high and low speeds and presents a detailed probabilistic methodology (fault tree) for assessing ejection frequency. The alpha factor methodology is applied to common-cause failure evaluations. The frequencies under different test schemes are compared and the propagation of uncertainty through the fault tree model is evaluated. The following conclusions were reached: (1) the turbine blade ejection frequency due to ductile failure under high speed is around 8.005E-7/yr; (2) if common-cause failure is considered, the frequency will be increased by 11% and 33% depending on the test scheme; and (3) if the parameter uncertainties are considered, the frequency is estimated to be in the range of 9.35E-7 to 1.13E 6, with 90% confidence.
- KHNP, Kori units 3&4 Turbine-Generator System P&ID.
- KHNP, 2004, Kori units 3&4 Final Probabilistic Safety Assessment Report.
- Spencer H. Bush, 1973, "Probability of Damage to Nuclear Components Due to Turbine Failure," Nuclear Safety.
- Rosario, D., 2001, "Technical Approach to Turbine Missile Probability Assessment," EPRI TR 10006451.
- PRA Procedures Guide, 1982, NUREG/CR-2300, ANS and IEEE.
- Park, C.K. and Ha, J.J., 2003, "Probabilistic Safety Assessment," KAERI.
- Oh, J.Y. and Kim, O.G., 2010, "Test Interval Extension of Kori 3&4 Turbine Overspeed Protection System Valve," NETEC.
- Mosleh, A., 1998, "Guidelines on Modeling Common Cause Failures in Proabilistic Risk Assessment," NUREG/CR-5485.
- 2007, "CCF Parameter Estimations 2007," updating data for NUREG/CR-5485, NRC.
- Ang, A. and Tang, W., 1975, "Probability Concepts in Engineering Planning and Design," Wiley & Sons.
- Modarres, M., 1999, "Reliability Engineering and Risk Analysis," Marcel Dekker.
- Shooman, M., 1968, "Probabilistic Reliability of Engineering Approach," McGraw-Hill.