Safety Assessment for Emergency Diesel Generator(EDG) Allowed Outage Time(AOT) Extension using Risk-informed

리스크정보를 활용한 비상디젤발전기 허용정지시간 연장시 안전성평가

  • Lim, Hyuk-Soon (Reliability Engineering Team, Nuc1ear Engineering & Technology Institute) ;
  • Kim, Doo-Hyun (Department of Safety Engineering, Chungbuk National University)
  • Received : 2010.01.04
  • Accepted : 2010.06.18
  • Published : 2010.06.30


In order to provide the necessary operation flexibility during the Nuclear power operation, the extension of existing allowed outage time(AOT) is needed. The extension of AOT affects the Nuclear power plant safety. The validity of changed technical specification requirements should be proved by the safety assessments. In this paper, we evaluated the extension of emergency diesel generator AOT for a single inoperable emergency diesel generator(EDG) from 3days to 7days, 10days and 14days. Finally, the AOT extension contributes the NPP performances through decreasing the unexpected plant trips, reinforcing maintenance and avoiding risks due to unnecessary operation mode changes when the NPP is under the surveillance tests or maintenance.


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