Document: NRC Regulatory Guide
Document ID: cdc706d5-60ed-40a4-b55a-9771904107a7
Document Type: regulatory_guide
Title: Seismic Qualification of Electric and Mechanical Equipment for Nuclear Power Plants (Rev. 4)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1809/ML18093A675.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.100
CFR Part: 
CFR Title: 

Content:
rust might be needed at unseating or in the flow stream. • Partial valve stroking did not reveal the total thrust needed to operate the valve. • Torque, thrust, and motor-operating parameters were needed to fully characterize MOV performance. • Reliable use of MOV diagnostic data requires accurate equipment and trained personnel. To assist NPP licensees in responding to GL 89-10, the Electric Power Research Institute (EPRI) developed the MOV performance prediction methodology to determine the minimum dynamic thrust and torque requirements for gate, globe, and butterfly valves based on first principles of MOV design and operation. EPRI Topical Report (TR)-103237, “EPRI MOV Performance Prediction Program,” Revision 2, issued April 1997 (Ref. 17), describes the methodology. In March 1996, the NRC staff issued “Safety Evaluation on EPRI MOV Performance Prediction Methodology” (Ref. 18), finding the EPRI program to provide an acceptable methodology with certain conditions and limitations. The NRC staff also issued supplements to the safety evaluation in February 1997 (Ref. 19), April 2001 (Ref. 20), September 2002 (Ref. 21), and February 2009 (Ref. 22) to address updates to the EPRI MOV program. The NRC staff alerted licensees to lessons learned from the EPRI program in NRC Information Notice 96-48, “Motor-Operated Valve Performance Issues,” dated August 21, 1996 (Ref. 23). DG-1328, Page 8 In the late 1990s, the NRC conducted research to study the performance of alternating current (ac)-powered MOV motor actuators manufactured by Limitorque Corporation (Limitorque) under various temperature and voltage conditions. The NRC documented its study of ac-powered MOV output in NUREG/CR-6478, “Motor-Operated Valve (MOV) Actuator Motor and Gearbox Testing,” issued July 1997 (Ref. 24). In response to the new information on ac-powered MOV performance, Limitorque updated its guidance in Technical Update 98-01, “Actuator Output Torque Calculation,” issued