U.S. Nuclear Regulatory Commission Operations Center Event Reports For 11/15/94 - 11/16/94 ** EVENT NUMBERS ** 28031 28032 28033 +----------------------------------+ +-----------------------+ |GENERAL INFORMATION or OTHER | |EVENT NUMBER: 28031 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |LICENSEE: ROSEMOUNT NUCLEAR INSTRUMENTS |NOTIFICATION DATE: 11/15/94 | | CITY: EDEN PRAIRIE REGION: 3 |NOTIFICATION TIME: 13:34 [ET]| | COUNTY: STATE: MN |EVENT DATE: 11/10/94 | |LICENSE#: AGREEMENT: N |EVENT TIME: 00:00[CST]| | DOCKET: |LAST UPDATE DATE: 11/15/94 | | +-----------------------------+ | |PERSON ORGANIZATION| | | | | | | +------------------------------------------------+ | |NRC NOTIFIED BY: FACSIMILE | | |HQ OPS OFFICER: WILLIAM HUFFMAN | | +------------------------------------------------+ | |EMERGENCY CLASS: NOT APPLICABLE | | |10 CFR SECTION: | | |CDEF 21.21(b)(2) DEFECTS/NONCOMPLIANCE | | | | | | | | | | | | | | +------------------------------------------------+-----------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | CHANGE IN OVERPRESSURE EFFECT TESTING IN RANGE 4 DIFFERENTIAL PRESSURE | | TRANSMITTERS. | | | | ROSEMONT NUCLEAR GRADE RANGE 4 DIFFERENTIAL PRESSURE TRANSMITTERS (MODELS | | 1152, 1153, AND 1154) HAVE EXHIBITED A CHANGE IN PERFORMANCE WHEN SUBJECTED | | TO THE STANDARD TWO-SIDED OVERPRESSURE TEST. TO IMPROVE THE POST TESTING | | PERFORMANCE CHARACTERISTICS OF THESE DIFFERENTIAL TRANSMITTERS, A NEW, LESS | | CONSERVATIVE OVERPRESSURE EFFECTS TEST HAS BEEN IMPLEMENTED BY ROSEMONT. | | THE REVISED TEST HAS BEEN USED ON ALL RANGE 4 DIFFERENTIAL PRESSURE | | TRANSMITTERS SHIPPED SINCE JANUARY 6, 1994. | | | | THE OVERPRESSURE EFFECT IS DEFINED AS THE EXPECTED SHIFT IN TRANSMITTER | | ZERO AFTER THE UNIT IS SUBJECTED TO A PRESSURE INPUT MAGNITUDE GREATER THAN | | THE SENSOR UPPER RANGE VALUE. THE OVERPRESSURE SPECIFIED FOR THE | | TRANSMITTER IN QUESTION IS 2000 PSI. | | | | THE TWO-SIDED OVERPRESSURE TEST IS ONE IN WHICH MAXIMUM OVERPRESSURE IS | | APPLIED FIRST TO ONE SIDE OF THE SENSOR, WHERE A ZERO READING IS TAKEN | | AFTER PRESSURE IS RELEASED. PRESSURE IS THEN APPLIED TO THE OPPOSITE SIDE | | WHERE A SECOND ZERO READING IS TAKEN. THE DIFFERENCE BETWEEN THE TWO | | READINGS IS THE OVERPRESSURE EFFECT. | | | | OVER TIME, THE RANGE 4 DIFFERENTIAL PRESSURE TRANSMITTERS HAVE DEMONSTRATED | | A CHANGE IN PERFORMANCE RELATIVE TO THE OVERPRESSURE EFFECT. ROOT CAUSE | | INVESTIGATION HAS NOT IDENTIFIED A SPECIFIC CAUSE. HOWEVER, THE CHANGE IN | | OVERPRESSURE PERFORMANCE CHARACTERISTICS DOES NOT AFFECT ANY OTHER | | TRANSMITTER VARIABLES (SUCH AS ACCURACY; DRIFT; TEMPERATURE PERFORMANCE; | | STATIC PRESSURE; RADIATION; SEISMIC; ETC). | | | | IN ORDER TO CONTINUE TO MEET THE OVERPRESSURE PERFORMANCE SPECIFICATIONS | | FOR RANGE 4 DP TRANSMITTERS, A NEW TEST PROCEDURE WAS IMPLEMENTED ON | | 1/6/94. THE NEW TEST PROCEDURE IS LESS CONSERVATIVE THAN THE ORIGINAL TEST | | BUT REMAINS MORE CONSERVATIVE THAN OVERPRESSURE CONDITIONS EXPECTED IN THE | | FIELD. THE NEW OVERPRESSURE TEST DOES NOT COMPARE THE ZERO SHIFT CAUSED BY | | A HIGH SIDE OVERPRESSURE WITH THE ZERO SHIFT CAUSED BY A LOW SIDE | | OVERPRESSURE. INSTEAD, IT COMPARES THE ZERO SHIFT CAUSED BY A FULL SCALE | | PRESSURE WITH THE ZERO SHIFT CAUSED BY A 2000 PSIG OVERPRESSURE TO THE | | OPPOSITE SIDE OF THE DIAPHRAGM. THE SEQUENCE IS REPEATED FOR BOTH SIDES OF | | THE SENSOR, AND, IS A MUCH MORE REALISTIC TEST OF ACTUAL OPERATING | | CONDITIONS. | | | | A COPY OF THE PART 21 REPORT ON THIS CONDITION HAS BEEN SENT TO | | NRR/TQMB(HAASS). | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |GENERAL INFORMATION or OTHER | |EVENT NUMBER: 28032 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |LICENSEE: CALVERT CLIFFS NUCLEAR POWER PLANT |NOTIFICATION DATE: 11/15/94 | | CITY: LUSBY REGION: 1 |NOTIFICATION TIME: 15:56 [ET]| | COUNTY: STATE: MD |EVENT DATE: 11/11/94 | |LICENSE#: AGREEMENT: Y |EVENT TIME: 12:00[EST]| | DOCKET: |LAST UPDATE DATE: 11/15/94 | | +-----------------------------+ | |PERSON ORGANIZATION| | | | | | | +------------------------------------------------+ | |NRC NOTIFIED BY: CRAIG SLY | | |HQ OPS OFFICER: WILLIAM HUFFMAN | | +------------------------------------------------+ | |EMERGENCY CLASS: NOT APPLICABLE | | |10 CFR SECTION: | | |CDEF 21.21(b)(2) DEFECTS/NONCOMPLIANCE | | | | | | | | | | | | | | +------------------------------------------------+-----------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | STUCK GOVERNOR VALVE ON AUXILIARY FEEDWATER PUMP (AFW). | | | | CALVERT CLIFFS REPORTS THAT THEY HAVE RECENTLY EXPERIENCED SEVERAL | | INSTANCES OF THE GOVERNOR VALVE STICKING ON ONE OF THEIR AFW PUMPS. THE AFW | | TURBINE UNIT IS MANUFACTURED BY THE TERRY STEAM TURBINE COMPANY. DRESSER - | | RAND IS THE AFW TURBINE DRIVEN PUMP VENDOR. | | | | ROOT CAUSE ANALYSIS OF THE PROBLEM HAS DETERMINED THAT THE BINDING WAS DUE | | TO GALVANIC AND CREVICE CORROSION ON THE VALVE STEM BROUGHT ABOUT BY A | | COMBINATION OF SEVERAL IMPROPER MATERIAL CONDITIONS. SPECIFICALLY, THE USE | | OF 300 SERIES STAINLESS STEEL IN LIEU OF 400 SERIES FOR THE VALVE PACKING | | GLAND WASHERS. ALSO, SULFUR CONTAMINATION IN THE CARBON SPACERS OF THE | | VALVE PACKING GLAND. IN ADDITION, AN EXTREMELY THIN, ESSENTIALLY | | NON-EXISTENT, NITRIDED LAYER ON THE SURFACE OF THE VALVE STEM ALLOWED | | CORROSION TO PENETRATE INTO BASE STEM MATERIAL. | | | | THE LICENSEE HAS FOUR TURBINE DRIVEN AFW PUMPS. THE PUMP WITH THE GOVERNOR | | VALVE PROBLEMS HAD THE VALVE STEM REPLACED IN 1994. THE VALVE STEMS ON THE | | OTHER THREE PUMPS ARE THE ORIGINAL STEMS AND HAVE NOT BEEN REPLACED. | | | | TO MITIGATE THE CHANCE OF THE GOVERNOR VALVE STICKING PROBLEMS, THE | | LICENSEE PLANS TO PERIODICALLY EXERCISE THE VALVE STEMS. | | | | THE LICENSEE NOTES THAT THIS CONDITION HAS BEEN REPORTED BY OTHER LICENSEES | | AND IS DOCUMENTED IN INFORMATION NOTICE 94-66. | | | | A COPY OF THE PART 21 REPORT ON THIS CONDITION HAS BEEN SENT TO NRR/TQMB | | (HAASS) | +------------------------------------------------------------------------------+ +----------------------------------+ +-----------------------+ |GENERAL INFORMATION or OTHER | |EVENT NUMBER: 28033 | +----------------------------------+ +-----------------------+ +------------------------------------------------+-----------------------------+ |LICENSEE: UNITED CONTROLS INTERNATIONAL, INC |NOTIFICATION DATE: 11/15/94 | | CITY: STONE MOUNTAIN REGION: 2 |NOTIFICATION TIME: 16:43 [ET]| | COUNTY: STATE: GA |EVENT DATE: 11/03/94 | |LICENSE#: AGREEMENT: Y |EVENT TIME: 12:00[EST]| | DOCKET: |LAST UPDATE DATE: 11/15/94 | | +-----------------------------+ | |PERSON ORGANIZATION| | | | | | | +------------------------------------------------+ | |NRC NOTIFIED BY: FACSIMILE | | |HQ OPS OFFICER: WILLIAM HUFFMAN | | +------------------------------------------------+ | |EMERGENCY CLASS: NOT APPLICABLE | | |10 CFR SECTION: | | |CDEF 21.21(b)(2) DEFECTS/NONCOMPLIANCE | | | | | | | | | | | | | | +------------------------------------------------+-----------------------------+ EVENT TEXT +------------------------------------------------------------------------------+ | NOTIFICATION OF SEQUENCER DEFECT. | | | | DURING SAFEGUARDS TESTING AT TURKEY POINT ON 11/3/94, THE UNIT 3A SEQUENCER | | FAILED TO START A SAFETY INJECTION PUMP UPON RECEIVING A VALID SAFETY | | INJECTION SIGNAL. THE SEQUENCERS AT TURKEY POINT WERE SUPPLIED AS NUCLEAR | | QUALIFIED SAFETY RELATED UNITS TO FP&L BY THE UNITED CONTROLS DIVISION OF | | HUB INC. IN OCTOBER OF 1990. | | | | INVESTIGATION DETERMINED THAT THE PROBLEM WAS THE RESULT OF A SOFTWARE | | LOGIC ERROR THAT CAUSES A SAFETY INJECTION INHIBIT SIGNAL TO SEAL IN UNDER | | CERTAIN CONDITIONS OF THE AUTO-TEST MODE. THIS CONDITION IS PRESENT | | APPROXIMATELY 25% OF THE TIME AND WILL PREVENT THE SEQUENCER FROM PROPERLY | | RESPONDING TO ANY SAFETY INJECTION SIGNAL. | | | | THE SOFTWARE PROGRAM FOR THE FP&L SEQUENCERS IS UNIQUE TO TURKEY POINT. NO | | OTHER FACILITIES ARE AFFECTED. | | | | THE LOGIC ERROR ESCAPED DETECTION DURING THE LOGIC REVIEW. THE TEST PLAN | | FOR THE SOFTWARE INCLUDED VERIFYING THE PROPER RESPONSE TO EVERY CREDIBLE | | INPUT/OUTPUT SIGNAL COMBINATION. THE TEST PLAN TO VERIFY THE SYSTEM WOULD | | PROPERLY RESPOND WHILE IN THE AUTO-TEST MODE WAS DEVELOPED ON THE BASIS | | THAT IT WOULD BE SUFFICIENT TO CHECK ALL CREDIBLE INPUTS/OUTPUTS WHILE THE | | SYSTEM RAN AN AUTO-TEST. THIS WAS DONE SATISFACTORILY. HOWEVER, THERE ARE | | APPARENTLY SIXTEEN DIFFERENT AUTO-TEST SCENARIOS. THE ONLY WAY TO HAVE | | DETECTED THE ERROR WOULD HAVE REQUIRED TESTING EVERY CREDIBLE COMBINATION | | OF INPUTS/OUTPUTS DURING EACH OF THE SIXTEEN AUTO-TEST SCENARIOS. | | | | UNITED CONTROLS HAS NOT BEEN INVOLVED IN ANY QA OR V&V ON THE SEQUENCERS | | SINCE 10/15/91. BECAUSE PROGRAMMING CHANGES HAVE BEEN MADE SINCE THIS DATE, | | UNITED CONTROLS IS NO LONGER IN A POSITION TO CORRECT THE SPECIFIC DEFECT | | WITHOUT A POTENTIAL FOR ADVERSELY AFFECTING EXISTING SOFTWARE. | | CONSEQUENTLY, UNITED CONTROLS PLANS NO OTHER EVALUATION OF THIS DEFECT | | UNLESS CONTACTED BY FP&L TO PERFORM PROGRAMMING CHANGES AND SUBSEQUENT V&V | | TO THE SEQUENCER SOFTWARE. | | | | A COPY OF THE PART 21 REPORT ON THIS CONDITION HAS BEEN SENT TO | | NRR/TQMB(HAASS). | +------------------------------------------------------------------------------+