FATIGUE ISSUES FOR LIFE EXTENSION AND LICENSE RENEWAL

Fatigue has been identified as a technical issue potentially affecting the license renewal of nuclear power plants. The NEI License Renewal Industry Reports (IRs) maintained that the current fatigue licensing b asis (CFLB) is adequate to manage the effects of fatigue for both the current and the license renewal term, provided that fatigue-sensitive locations are accounted for and managed appropriately. The Nuclear Reg ulatory Commission (NRC) has identified fatigue as a Generic Safety Is sue 166, Adequacy of Fatigue Life of Metal Components. The concerns id entified by the NRC in GSI-166 must be evaluated as part of the licens e renewal process. The concerns of the NRC staff regarding fatigue for license renewal fall into five categories: (I) adequacy of the fatigu e design basis when environmental effects are considered; (2) adequacy of both the number and severity of design-basis transients; (3) adequ acy of inservice inspection requirements and procedures to detect fati gue indications; (4) adequacy of the fatigue design basis for Class 1 piping components designed in accordance with ANSI B31.1; and (5) adeq uacy of actions to be taken when the fatigue design basis is potential ly compromised. Results of recent investigations by EPRI (Electric Pow er Research Institute) and other organizations are being used to provi de technical justification to support development of an industry appro ach regarding the management of fatigue during the license renewal ter m. This paper describes industry activities to develop a fatigue posit ion for license renewal. (C) 1998 Elsevier Science S.A. All rights res erved.