ENS 46955

v t e ENS Event
15:52 Jun 7, 2011
Title	Nonconservative Valve Actuator Program Software
Event Description	In Kalsi Engineering Valve and Actuator Program (KVAP) Error Report 2011-02, Kalsi Engineering identified an error in the KVAP software that provides default flow and torque coefficients for ball and plug valves which can affect margin predictions. Communication between Kalsi and Duke Energy personnel confirmed that non-conservative torque values were calculated for select ball valves used at Oconee for containment isolation. As a result of the Kalsi error, the non-conservatively calculated torque values resulted in negative actuator margins, calling into question the actuators' capability to close the valves under all design conditions. Therefore, it has been determined that the KVAP software program error constitutes a defect, reportable under 10CFR21. Four safety-related containment isolation valves in the High Pressure Injection system were impacted, requiring entry into TS 3.6.3, Containment Isolation Valves, on two Oconee units [Units 2 and 3]. Unit 1 was shutdown for a refueling outage at the time of this event and the actuator spring was replaced during the outage. The valves on units 2 and 3 required a Notification of Enforcement Discretion (NOED) which occurred on June 2, 2011. Three of the four valves were declared operable on June 10, 2011 and the remaining valve was declared operable the next day. The licensee notified the NRC Resident Inspector.

ENS 46955 +/-
Where
Oconee South Carolina (NRC Region 2)
Reporting

10 CFR 21.21
Time - Person (Reporting Time:+144.2 h6.008 days <br />0.858 weeks <br />0.198 months <br />)
Opened:	Sandra Severance 16:04 Jun 13, 2011
NRC Officer:	Mark Abramovitz
Last Updated:	Jun 13, 2011
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v • d • e

v t e Emergency Notification System
Oconee with 10 CFR 21.21
WEEKMONTHYEAR2011-06-07T15:52:00 [Table view]
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