Session: OAC-07-01: Plant Life Extension: Aging and Life Management

Paper Number: 84194

84194 - Environmentally Assisted Fatigue Screening Process Application 

In the frame of extension of nuclear plant operation life, environmentally assisted fatigue (EAF) assessment is required by regulators to be considered. The methodology of EAF assessment, through EAF cumulative usage factor (CUFen) calculations, has been integrated in RPP n°3 (Rule in Probationary Phase) of French RCC-M code. This methodology is applicable to sentinel locations of Class 1 components of austenitic steels and nickel based steels that have been identified in advance.

In order to minimize final number of sentinel locations for considering EAF effects, EAF screening methods are presented in EPRI report 3002018262, which allow to rank the CUFen values and give a list of sentinel locations that assumed to cover other locations within each thermal zone. In particular, the EDF Screening method is based on RCC-M code using Fen-integrated concept.

The EDF Screening method is not applicable for locations without an explicit fatigue analysis or without any pair loads information. In this paper, a new screening method is proposed based on RCC-M code, similar to the EDF method. Environmental fatigue factor (Fen) is estimated by a simple process for each location. The CUFen is determined using Fen and Fen-integrated concept. For locations without an explicit CUF calculation, fatigue tables will be estimated according to the analytical method described in B3600 of RCC-M for piping components. Finally, the sentinel locations identified will be compared to those selected in EPRI report.

Presenting Author: Jia Li Framatome

Presenting Author Biography: Jia LI is mechanical engineer at Framatome. She got a PHD degree in simulation of fatigue crack propagation. Her main research domains are fatigue analysis and fatigue crack propagation simulation.

Authors:

Jia Li Framatome
Laurent De Baglion Framatome