Issue:
By letter dated October 26, 2004, Electric Power Research Institute (EPRI) notified affected members in accordance with 10 CPR 21.21(b), of a non-conservatism in the [software product of] EPRI Motor Operated Valve Performance Prediction Methodology (PPM), Versions 1.0 through 3.2, to predict total required dynamic torque under compressible flow conditions for actuators for butterfly valves with single disc offset designs. As explained in the error notice, the non-conservatism could be as much as 45 percent. This non-conservatism could potentially jeopardize the design basis operation of associated safety related applications.
Southern Nuclear Company (SNC) subsequently performed an engineering evaluation based on the EPRI notification as it related to Vogtle Electric Generating Plant (VEGP). The assessment did not identify any instances where the PPM had actually been used for such purposes at VEGP.
Corrective Action:
This issue has been entered into the
SNC Corrective Action Program.
SNC will evaluate the restrictions, adjustments, and recommendations regarding use of the
EPRI MOV PPM, Versions 1.0 through 3.2, that were communicated in
EPRI PPM Software Error Notice 2004-2.
