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Part 21 Report - 1996-801

ACCESSION #: 9611260325 POWER REACTOR EVENT NUMBER: 31371 FACILITY: MILLSTONE REGION: 1 NOTIFICATION DATE: 11/22/96 UNIT: [ ] [ ] [3] STATE: CT NOTIFICATION TIME: 14:05[ET] RX TYPE: [1] GE-3, [2] CE, [3] W-4-LP EVENT DATE: 09/25/96 EVENT TIME: 00:00 [EST] LAST UPDATE DATE: 11/22/96 NRC NOTIFIED BY: JAMES PESCHEL HQ OPS OFFICER: STEVE SANDIN NOTIFICATION EMERGENCY CLASS: NOT APPLICABLE 10 CFR SECTION: CCCC 21.21 UNSPECIFIED PARAGRAPH UNIT SCRAM CODE RX CRIT INIT PWR INIT RX MODE CURR PWR CURR RX MODE 3 N N 0 COLD SHUTDOWN 0 COLD SHUTDOWN EVENT TEXT THE LICENSEE IS MAKING A PART 21 NOTIFICATION. "IN ACCORDANCE WITH 10 CFR 21.21(d)(3)(i), NORTHEAST NUCLEAR ENERGY COMPANY (NNECO) IS PROVIDING NOTIFICATION TO THE NRC VIA THIS FACSIMILE AND CONCURRENT TELEPHONE CONVERSATION, REGARDING A POTENTIAL SIGNIFICANT SAFETY HAZARD (SSH) IDENTIFIED AT MILLSTONE STATION." "FIFTEEN DIFFERENT FUSE TYPES FROM THREE DIFFERENT MANUFACTURERS (GOULD- SHAWMUT, BUSSMAN, AND CEFCO) WERE FOUND TO HAVE AXIAL CRACKS. THE CRACKS OCCURRED AS A RESULT OF THE BRASS FERRULE RELIEVING INTERNAL STRESS. "DURING COMMUNICATIONS WITH MANUFACTURERS, IT WAS DETERMINED THAT THESE DEFECTS HAVE BEEN PRESENT WITHIN THE FUSE INDUSTRY FOR MANY YEARS AND THAT FUSES MANUFACTURED WITH BRASS ARE SUSCEPTIBLE TO THIS DEFECT." "NNECO DETERMINED THAT FUNCTIONAL TESTING SHOULD BE PERFORMED ON A SAMPLE OF THE FUSES. THE RESULTS FROM THE TESTING INDICATED THAT THE FUSES MET THEIR INTENDED FUNCTION OF INTERRUPTING THE CURRENT, HOWEVER TEN OUT OF FORTY SIX FUSES HAD FERRULES PHYSICALLY BLOW OFF THE END. THE FOLLOWING IS A LIST OF THOSE FUSES THAT THE FERRULE(S) CAME OFF THE END: GOULD-SHAWMUT A6Y2 TYPE II, 10KA IR A6Y5, 200KA IR TRM25, 10KA IR A4J10, 200KA IR (2) (Continued on next page) FACILITY: MILLSTONE PAGE # 2 OF EVENT NUMBER: 31371 BUSSMAN FRN12, 200KA IR FRN-R25, 200KA IR FRN-R30, 200KA IR FRN-R35, 200KA IR FRN-R60, 200KA IR" "CONCLUSION: THE CRACKS COULD RESULTS IN A LOSS OF SAFETY-RELATED EQUIPMENT DUE TO THE FERRULE COMING OFF OF THE FUSE, WHICH COULD THEN SHORT OUT OR DAMAGE OTHER SAFETY-RELATED ELECTRICAL DISTRIBUTION. THIS COULD BE A SSH CONCERN THAT SHOULD BE REPORTED THROUGH 10CFR21, WITH NOTIFICATION TO OTHER UTILITIES DUE TO THE GENERIC NATURE OF THE BASIC COMPONENT." "IN ACCORDANCE WITH 10CFR 21.21(d)(3)(ii), A WRITTEN REPORT WILL BE PROVIDED WITHIN 30 DAYS." Northeast TELECOPIER COVER LETTER Utilities System (FAX) [Illegible] DATE TIME TOTAL NUMBER OF PAGES BEING SENT: (Including this page) COMPANY TO: DEPARTMENT/ DIVISION ATTENTION TELEPHONE NUMBER TELECOPIER TELEPHONE NUMBER (INCLUDE AREA CODE) NAME ROOM NO. TELEPHONE NUMBER*_/ FROM: DEPARTMENT/DIVISION TELECOPIER NUMBER (INCLUDE AREA CODE) _________________________ *_/ IF YOU DID NOT RECEIVE ALL OF THE PAGES PLEASE CALL THIS NUMBER _________________________ COMMENTS/DIRECTIONS Northeast Nuclear Energy Company SUBSTANTIAL SAFETY HAZARD REPORT November 22, 1996 In accordance with 10 CFR 21.21(d)(3)(i), Northeast Nuclear Energy Company (NNECO) is providing notification to the NRC via this facsimile and concurrent telephone conversation, regarding a potential Significant Safety Hazard (SSH) identified at Millstone Station. o Fifteen different fuse types from three different manufactures (Gould-Shawmut, Bussmann, and CEFCO) were found to have axial cracks. The cracks occurred as a result of the brass ferrule relieving internal stress. o During communications with manufacturers, it was determined that these defects have been present within the fuse industry for many years and that fuses manufactured with brass are susceptible to this defect. o NNECO determined that functional testing should be performed on a sample of the fuses. The results from the testing indicated that the fuses met their intended function of interrupting the current, however ten out of forty six fuses had ferrules physically blow off the end. The following is a list of those fuses that the ferrule(s) came off the end. Gould-Shawmut Bussmann A6Y2 Type II, 10KA IR FRN 12, 200KA IR A6Y5, 200KA IR FRN-R25, 200KA IR TRM25, 10KA IR FRN-R30, 200KA IR A4J10, 200KA IR (2) FRN-R35, 200KA IR FRS-R60, 200KA IR Conclusion The cracks could result in a loss of safety-related equipment due to the ferrule coming off of the fuse, which could then short out or damage other safety-related electrical distribution. This could be a SSH concern that should be reported through 10CFR21, with notification to other utilities due to the generic nature of the basic component. If you have any questions regarding this information, please contact Mr. James K Peschel at (860) 437-5840. In accordance with 10CFR 21.21(d)(3)(ii), a written report will be provided within 30 days, *** END OF DOCUMENT ***

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