United States Nuclear Regulatory Commission - Protecting People and the Environment

Common-Cause Failure Event Insights: Motor-Operated Valves (NUREG/CR-6819, INEEL/EXT-99-00613, Volume 2)

On this page:

Download complete document

Publication Information

Manuscript Completed: March 2003
Date Published: May 2003

Prepared by:
T.E. Wierman, INEEL
D.M. Rasmuson, NRC
N.B. Stockton, INEEL

Risk & Reliability Assessment Department
Idaho National Engineering and Environmental Laboratory
Lockheed Martin Idaho Technologies Company
P.O. Box 1625
Idaho Falls, Idaho 83415-3850

T.R. Wolf, NRC Project Manager

Prepared for:
Division of Risk Analysis and Applications
Office of Nuclear Regulatory Research
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001

NRC Job Code Y6194

Availability Notice


This report documents a study performed on the set of common-cause failures (CCF) of motor-operated valves (MOV) from 1980 to 2000. The data studied here were derived from the NRC CCF database, which is based on U.S. commercial nuclear power plant event data. This report is the result of an in-depth review of the MOV CCF data and presents several insights about the MOV CCF data. The objective of this document is to look beyond the CCF parameter estimates that can be obtained from the CCF data, to gain further understanding of why CCF events occur and what measures may be taken to prevent, or at least mitigate the effect of, MOV CCF events. This report presents quantitative presentation of the MOV CCF data and discussion of some engineering aspects of the MOV events.

Page Last Reviewed/Updated Friday, March 13, 2020