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UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION WASHINGTON, D.C. 20555 May 19, 1993 NRC INFORMATION NOTICE 93-37: EYEBOLTS WITH INDETERMINATE PROPERTIES INSTALLED IN LIMITORQUE VALVE OPERATOR HOUSING COVERS Addressees All holders of operating licenses or construction permits for nuclear power reactors. Purpose The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to alert addressees to problems that could result from eyebolts with indeterminate properties installed in Limitorque valve operator housing covers. It is expected that recipients will review the information for applicability to their facilities and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice are not NRC requirements; therefore, no specific action or written response is required. Description of Circumstances During recent inspections at the Crystal River Nuclear Plant and the Virgil C. Summer Nuclear Station, the NRC found Limitorque model SMB-000 and SMB-00 valve operators in which two of the housing cover bolts were replaced with an eyebolt and nut combination. The licensees reviewed their design change programs but did not find any documentation for the installation of the eyebolts. The affected valve operators were installed in safety- and nonsafety-related applications. Some of the affected valve operators were installed on butterfly valves through a worm-drive gearbox such that the housing cover bolts do not experience stem thrust during valve operation. However, some of the affected safety-related valve operators were installed on gate valves and globe valves such that the housing cover bolts do experience stem thrust forces during valve operation. The housing cover bolts transmit valve stem thrust to the operator housing and ultimately to the valve yoke. The bolts are listed as critical to valve operator function in the Limitorque Critical Component List. Discussion South Carolina Electric and Gas (SCE&G), the licensee for Summer, determined that the affected valve operators arrived from the Limitorque Corporation, the 9305130037. IN 93-37 May 19, 1993 Page 2 of 2 valve operator vendor, with the eyebolts installed. In a letter to SCE&G of December 11, 1992, Limitorque confirmed that it had shipped valve operators with eyebolts installed since the early 1970s, that Limitorque did not control the eyebolt material, and that therefore it could not yet address the qualification of the eyebolt material for actuator operation. Limitorque representatives stated that they had not received any reports of failures associated with the eyebolts. Limitorque has issued Maintenance Update 92-2, in which it discusses this problem in paragraph 9, and recommends that the eyebolts be replaced by grade 5 housing cover bolts at the next scheduled maintenance. The NRC staff believes that ungraded eyebolts are probably installed in various safety-related applications at other facilities since this condition was not previously documented by the vendor. The NRC has attached an excerpt from the Limitorque Maintenance Update 92-2 because all licensees may not automatically receive Limitorque maintenance updates. This information notice requires no specific action or written response. If you have any questions about the information in this notice, please contact one of the technical contacts listed below or the appropriate Office of Nuclear Reactor Regulation (NRR) project manager. ORIGINAL SIGNED BY Brian K. Grimes, Director Division of Operating Reactor Support Office of Nuclear Reactor Regulation Technical contacts: Stephen Elrod, RII Richard Freudenberger, RII (407) 464-7822 (904) 795-7677 Lee Keller, RII Thomas Scarbrough, NRR (803) 345-5683 (301) 504-2794 Attachments: 1. Excerpt from Limitorque Maintenance Update 92-2 2. List of Recently Issued NRC Information Notices .ENDEND
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