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Information Notice No. 89-14: Inadequate Dedication Process for Commercial-Grade Components which could lead to Common Mode Failure of a Safety System
UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION WASHINGTON, D.C 20555 February 16, 1989 Information Notice No. 89-14: INADEQUATE DEDICATION PROCESS FOR COMMERCIAL- GRADE COMPONENTS WHICH COULD LEAD TO COMMON MODE FAILURE OF A SAFETY SYSTEM Addressees: All holders of operating licenses or construction permits for nuclear power reactors. Purpose: This information notice is being provided to alert addressees to potential problems resulting from an error made by a vendor in supplying a commercial- grade component of the wrong size and an inadequate dedication process by the licensee. It is expected that recipients will review the information for ap- plicability to their facilities and consider actions, as appropriate, to avoid similar problems. However, suggestions contained in this information notice do not constitute NRC requirements; therefore, no specific action or written response is required. Description of Circumstances: On July 7, 1988, during surveillance testing of the auxiliary feedwater pumps at the Rancho Seco station, the outboard packing on the dual-drive auxiliary feedwater pump overheated. The packing was replaced four times during the fol- lowing month because it overheated during surveillance or post-maintenance testing. The licensee then installed a packing supplied by a different vendor which was satisfactorily tested on August 14, 1988. Discussion: A review of these events by the licensee showed that the last four sets of packing supplied by the vendor were dimensionally incorrect and were installed in the pump without any verification of the actual dimensions. This type of problem has particularly significant safety implications because of the poten- tial to cause a common mode failure of a safety system. The packing was procured as commercial grade and upgraded for safety-related application by a review of the packing's critical characteristics. Size was one of the critical character-istics. However, the vendor considered the inside and outside diameters to be proprietary information, and this restriction contributed to the licensee's failure to perform an independent verification of the dimensions. The licensee verified the size by looking at the invoice for the packing and at the vendor's technical information. The vendor's error could not be detected by this level 8902100199 . IN 89-14 February 16, 1989 Page 2 of 2 of verification. The documentation matched the purchase order; however, the replacement packing was of the wrong size. In one of the four failures reported, inadequate maintenance testing failed to uncover the vendor's error. The packing did not overheat because the pump was not operated long enough. The packing over-heated during subsequent operation of the pump. Calculations by the licensee showed that in the event of a complete packing failure, the pump still would have fulfilled its safety function. However, the use of inadequately dedicated commercial-grade parts in nuclear facilities significantly increases the probability that safety-related systems may not perform their intended function. The licensee intends to take additional precautions to accurately verify critical characteristics of components before dedication. For instance, the dimensions of the packing will now be measured directly and compared to the shaft size. The licensee is also planning to increase the running time for post-maintenance testing. This event shows the importance in the dedication process to upgrade components from commercial grade to safety-related applications of licensees independently verifying the vendor's documentation. The event also demonstrates the necessity of adequate post-maintenance equipment testing. No specific action or written response is required by this information notice. If you have any questions about this matter, please contact the technical contact listed below or the Regional Administrator of the appropriate regional office. Charles E. Rossi, Director Division of Operational Events Assessment Office of Nuclear Reactor Regulation Technical Contact: Daniele Oudinot, NRR (301) 492-1174 Attachment: List of Recently Issued NRC Information Notices . Attachment IN 89-14 February 16, 1989 Page 1 of 1 LIST OF RECENTLY ISSUED NRC INFORMATION NOTICES _____________________________________________________________________________ Information Date of Notice No._____Subject_______________________Issuance_______Issued to________ 89-13 Alternative Waste Management 2/8/89 All holders of NRC Procedures in Case of Denial specific licenses. of Access to Low-Level Waste Disposal Sites 89-12 Dose Calibrator Quality 2/9/89 All NRC medical Control licensees. 89-11 Failure of DC Motor-Operated 2/2/89 All holders of OLs Valves to Develop Rated or CPs for nuclear Torque Because of Improper power reactors. Cable Sizing 89-10 Undetected Installation 1/27/89 All holders of OLs Errors In Main Steam Line or CPs for BWRs. Pipe Tunnel Differential Temperature-Sensing Elements at Boiling Water Reactors. 89-09 Credit for Control Rods 1/26/89 All holders of OLs Without Scram Capability or CPs for test and in the Calculation of the research reactors. Shutdown Margin 89-08 Pump Damage Caused by 1/26/89 All holders of OLs Low-Flow Operation or CPs for nuclear power reactors. 89-07 Failures of Small-Diameter 1/25/89 All holders of OLs Tubing in Control Air, Fuel or CPs for nuclear Oil, and Lube Oil Systems power reactors. Which Render Emergency Diesel Generators Inoperable 89-06 Bent Anchor Bolts in 1/24/89 All holders of OLs Boiling Water Reactor or CPs for BWRs Torus Supports with Mark I steel torus shells. _____________________________________________________________________________- OL = Operating License CP = Construction Permit ..
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