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Information Notice No. 82-55: Seismic Qualification of Westinghouse AR Relay with Latch Attachments Used in System
SINNS, No.: 6835 IN 82-55 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D. C. 20555 December 28, 1982 Information Notice No. 82-55: SEISMIC QUALIFICATION OF WESTINGHOUSE AR RELAY WITH LATCH ATTACHMENTS USED IN WESTINGHOUSE SOLID STATE PROTECTION SYSTEM Addressees: All holders of a nuclear power reactor operating license (OL) or construction permit (CP). Purpose: This Information Notice is provided as an early notification of a potentially significant problem pertaining to Westinghouse (W) AR relays fitted with type ARMLA latch devices which are not seismically qualified and may be used in safety-related systems at nuclear facilities. Specifically, the generic implications of the problem, as it applies to spare units, may affect both PWR and BWR operating plants and plants under construction. The Nuclear Regulatory Commission (NRC) staff is reviewing the problem and its effects. If the evaluation so indicates, NRC may request further licensee action. In the interim, we expect the recipients of this Information Notice to review the information herein for applicability to their facilities and to take appropriate actions. No specific action or response is required at this time. Description of Circumstances: Virginia Electric and Power Company (VEPCO) reported that one of the two types of latch mechanisms used with the Westinghouse type AR relay is not qualified for seismic Category 1 use. The licensee reports that both types of latch mechanisms are used in the Westinghouse solid state protection systems (SSPS) at both units of the North Anna Nuclear Power Station. One type of latch attachment, W ARLA performs the latch function by mechanical means; and the other type, W ARMLA performs the latch function by magnetic means. The ARMLA relay is a product replacement for the discontinued ARLA relay. The type ARMLA relay, used as a replacement for the type ARLA relay unit, was found by W to be seismically unqualified for use in the safety-grade SSPS. On December 14, 1982, Westinghouse Nuclear Service Division (NSD) issued Revision 1 of Technical Bulletin No. NSD-TB-82-03 to Westinghouse-supplied nuclear plants using the SSPS, apprising them of the problem. An extract from W NSD-TB-82-03 is attached for your information and appropriate use (Attachment 1). 8208190273 . IN 82-55 December 28, 1982 Page 2 of 2 The technical bulletin specifies an acceptable replacement unit, qualified by Westinghouse, which has been provided with an adaptor base for mounting in place of an AR relay unit. It is well to note, that since the AR relay is not unique to Westinghouse PWR power plants, the problem may also exist at other nuclear power plants. Therefore, it is advisable for all nuclear power plants to review their replacement and spare parts records to ascertain that no W ARMLA units have been installed, or are being held as spare parts, safety-related applications. If you have any questions regarding these matters please contact the Regional Administrator of the appropriate NRC Regional Office or this office. Edward L. Jordan, Director Division of Engineering and Quality Assurance Office of Inspection and Enforcement Technical Contact: V. D. Thomas 301-492-4755 Attachments: 1. Extract from Westinghouse Technical Bulletin NSD-TB-82-03, Rev. 1. 2. List of Recently Issued IE Information Notices . Attachment 1 IN 82-55 December 28, 1982 EXTRACT FROM WESTINGHOUSE TECHNICAL BULLETIN NSD-TB-82-03, "AR RELAY LATCH ATTACHMENTS," DATED JUNE 24, 1982 BACKGROUND INFORMATION In most of the Solid State Protection Systems (SSPS) in the field, Westinghouse Type AR relays were utilized as the slave relays, and those requiring latch features were fitted with type ARLA latch attachments which perform the latch function by mechanical means. The manufacturer has discontinued the ARLA latch attachments, replacing it with a line of ARMLA latch devices which perform the latch function via magnetic means. The ARMLA device, however, is an unqualified replacement fOr the safety grade SSPS. ... An acceptable seismically replacement is a ... latching relay, especially qualified by Westinghouse and provided with an adapter base for mounting in place of an AR relay. This assembly (... with conversion mounting bracket) is identified as Westinghouse EMD (Hunt Valley) Part Number 2388A31. There have been reports that some plants, after ordering replacement ARLA attachments, have received (and may have installed) unqualified ARMLA attachments. RECOMMENDATION All affected plants should review their replacement and spare records to make certain that no ARMLA devices have been installed, or are in spares, for safety grade applications. Our initial evaluation concluded that malfunctioning ARMLA devices could have no adverse impact on safety. However, review of new information has revealed the potential for spurious latching, or malfunctions which could prevent latching or unlatching when required. Although the NRC is aware of this information, neither they nor Westinghouse have sufficient information to clearly identify affected plants. Therefore, Westinghouse recommends that utilities which have installed ARMLA devices in the protection system consider reportability to the NRC. ARMLA magnetic latch attachments have a gold colored (brass) plunger protruding from the latch assembly, whereas the ARLA plunger is greyish or off-white non-metallic material. Spare or replacement requirements should be filled by the Westinghouse- qualified ... latching relay here no ARLA device is available.
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