ML20175A872

Risk-Informed Inservice Inspection - U.S Nuclear Regulatory Commission (NRC) - Four Element Risk-Informed Approach

ML20175A872
Person / Time
Site:	Calvert Cliffs, Peach Bottom, Nine Mile Point, Braidwood, Limerick, Ginna, Clinton
Issue date:	06/23/2020
From:	Blake Purnell Plant Licensing Branch III
To:
Wiebe J
References
Download: ML20175A872 (5)

Text

Risk-Informed Inservice Inspection US Nuclear Regulatory Commission (NRC)

Four Element Risk-Informed Approach

Risk-Informed Licensing Base Changes The four element approach defined in RG 1.174

1. Define the Proposed Change A list of all the all the types of valves binned into groups The function each type of valve group performs (may require sub-groups)

How position indication for valves in each group are currently verified Types of failures associated with position indication How these failures impact risk or PRA (If all valves are listed, the first three bullets may be simplified)

2. Perform Engineering Analysis The proposed change in verification procedures The types of changes to failures or failure rate associated with the proposed change The consequences of each failure mode and how each of these failures impact PRA or an existing risk-informed program.

Includes an evaluation of :

Associated change in risk for each valve failure in all its modes Associated impact of failure on safety margins Associated impact of failure on defense-in-depth

4. Submit Proposed Change