Morning Report for November 1, 1999
Headquarters Daily Report NOVEMBER 01, 1999 *************************************************************************** REPORT NEGATIVE NO INPUT ATTACHED INPUT RECEIVED RECEIVED HEADQUARTERS X REGION I X REGION II X REGION III X REGION IV X PRIORITY ATTENTION REQUIRED MORNING REPORT - HEADQUARTERS NOV. 01, 1999 Licensee/Facility: Notification: Part 21 Database MR Number: H-99-0091 Engine Systems Date: 11/01/99 Subject: Part 21 - Questionable Soldering in Woodward EGM Controllers Discussion: VENDOR: Engine Systems PT21 FILE NO: 99-40-0 DATE OF DOCUMENT: 09/22/99 ACCESSION NUMBER: 9909290055 SOURCE DOCUMENT: LETTER REVIEWER: REXB, T. Koshy NEW ISSUE. The vendor, Engine Systems, Inc., reports that Woodward type EGM controllers manufactured between December 1997 and May 1999 may have questionable soldering workmanship because of inadequate personnel training. Such controllers are commonly used on turbine applications. This issue was discovered by the Limerick licensee during visual inspection of internal components of an EGM controller. Deficiencies included wire strands, excessive solder flux (splash) and cold solder connections. A listing of affected customers, part numbers, and serial numbers is given at http://www.nrc.gov/NRC/PUBLIC/PART21/1999/1999400.html _ HEADQUARTERS MORNING REPORT PAGE 2 NOVEMBER 1, 1999 Licensee/Facility: Notification: Part 21 Database MR Number: H-99-0092 Abb Date: 11/01/99 Subject: Part 21 - Tripper Paddle Interference in ABB K-Line Circuit Breaker Discussion: VENDOR: ABB PT21 FILE NO: 99-41-0 DATE OF DOCUMENT: 09/23/99 ACCESSION NUMBER: SOURCE DOCUMENT: EN 36218 REVIEWER: REXB, D. Skeen NEW ISSUE. The Summer licensee reports that a refurbished K-Line circuit breaker, manufactured and refurbished by ABB, failed to trip because the shunt trip wires interfered with the red tripper paddle on the left side of the breaker. Other ABB K-Line breakers at the plant had the wires routed in a different direction, precluding interference with the paddle. On October 18, 1999, the licensee and vendor reported results of their inspection of 26 safety-related and 3 nonsafety-related breakers. One safety-related breaker was found to be affected and another safety-related breaker potentially affected. They determined that the following information should be provided to all licensees regarding this issue. Potentially affected ABB K-line breakers are of the following types: 1. All electrically-operated breakers with model numbers K-1600, K-1600S, K-2000, K- 2000S, and K-225 through K-800 2. Any mechanically- or electrically-operated breakers with the above model numbers that have auxiliary switches or shunt trip A trip-free condition, with respect to the overload trip function, could result for breakers having the shunt trip coil wiring on top of the tripper paddle. The overload trip could be prevented for breakers having the shunt trip coil wiring underneath the tripper paddle. The licensee corrected the problem by securing any wiring that could interfere with the proper operation of the tripper paddle. This problem is not limited to the breaker refurbishment or repair process by ABB Service. The licensee stated that this condition could occur on new breakers. _ HEADQUARTERS MORNING REPORT PAGE 3 NOVEMBER 1, 1999 Licensee/Facility: Notification: Part 21 Database MR Number: H-99-0093 Swagelok Date: 11/01/99 Subject: Part 21 - Potential Crack in Tube Fitting Seat Discussion: VENDOR: Swagelok PT21 FILE NO: 99-42-0 DATE OF DOCUMENT: 10/06/99 ACCESSION NUMBER: SOURCE DOCUMENT: EN 36263 REVIEWER: REXB, R. Benedict NEW ISSUE. The vendor, Swagelok Company, reports a possible defect in tube fitting part number SS-400-3-4TTM, male branch tee. The defect is a crack in the seat of the fitting. Swagelok is continuing its analysis. Affected nuclear power plants include Vogtle, Oconee, Palo Verde, Seabrook, Surry, and Ft. Calhoun. _ HEADQUARTERS MORNING REPORT PAGE 4 NOVEMBER 1, 1999 Licensee/Facility: Notification: Part 21 Database MR Number: H-99-0094 Brand Rex Date: 11/01/99 Subject: Part 21 - Damaged Safety-Grade Electrical Cabling Found in Supply Discussion: VENDOR: Brand Rex PT21 FILE NO: 99-43-0 DATE OF DOCUMENT: 10/06/99 ACCESSION NUMBER: SOURCE DOCUMENT: EN 36265 REVIEWER: REXB, C. Petrone NEW ISSUE. The Crystal River licensee reports finding damaged insulation on the same conductor in each of six samples of three-conductor cable (BICC Brand Rex Company power cable #1108582, 1 kV, 3/C, #2/0, Class B, 90C,XLPE Insulated, Black Jacket). The licensee was installing this cable, procured as safety-grade and environmentally qualified cable, in a nonsafety-related application. The licensee found the damage on removing the outer jacket for termination. The licensee learned from the vendor, Brand Rex, that during cable fabrication, while combining the three conductors before closing, the damaged conductor fell off the cabling unit pulley due to loss of tension, causing the insulation to be scraped. _ HEADQUARTERS MORNING REPORT PAGE 5 NOVEMBER 1, 1999 MR Number: H-99-0095 NRR DAILY REPORT ITEM SIGNIFICANT EVENTS Subject: Electrical Transient and Forced Outage at Beaver Valley, Unit 2, Classified As A Significant Event The Beaver Valley, Unit 2, July 16, 1999 event is classified as a Significant Event for the Performance Indicator Program. This classification is based on the degradation of the important safety systems that were revealed in this event as deficiencies in design, maintenance and operational area. During Emergency Diesel Generator (EDG) #2 test, while loaded to the safety bus, the bus supply breaker tripped and de-energized one train of the 4160v safety bus. This trip resulted in loss of thermal barrier heat exchanger cooling for two reactor coolant pumps (RCPs) and loss of seal cooling for all three reactor coolant pumps. In the absence of any systematic priority determination, the operators resolved to establish seal injection when 120 alarms were lit in the control room. The seal injection was established in less than three minutes, and the loss of all RCP cooling was not recognized by the operators until 15 minutes into the event. The annunciator response procedure for loss of seal injection would have directed the operator to trip the reactor immediately and the RCPs in two minutes with a concurrent loss of thermal barrier heat exchanger cooling. Operation of the RCPs without cooling could have led to a RCP seal LOCA. The de-energized safety bus disabled two battery chargers that supported two instrument channels of the safety grade dc buses. The licensee lacked procedures to recover the 4160v safety bus from abnormal conditions which partially influenced the bus recovery time of two hours. The batteries for the two instrument channels continued to deplete from the operational loads during these two hours. A subsequent equalizing charge for two hours brought one of the batteries only to the technical specification allowable value. Continued degradation of the dc buses could have hindered 4160v safety bus recovery. Two days before the electrical event, service water cooling to EDG #2 was significantly degraded (below its design basis value) after a chemical treatment was applied to prevent macro biological fouling (bio-fouling). After the plant had been shutdown, a second chemical treatment of the service water system resulted in the rapid degradation of service water flow to EDG #1. It was later revealed that a fortuitous personnel error was the only reason the initial chemical treatment did not affect both EDGs simultaneously. The licensee's bio-fouling treatment program had the potential to cause a common mode failure of all on-site emergency AC power. A later licensee calculation concluded that the actual flow was sufficient for heat removal for the river water temperatures that existed at the time. The Beaver Valley #2 design that disabled both of the RCP cooling systems HEADQUARTERS MORNING REPORT PAGE 6 NOVEMBER 1, 1999 MR Number: H-99-0095 (cont.) on loss of one safety bus, exposed the vulnerability for a seal LOCA on two RCPs. Lack of operator training to identify time critical duties increased the duration of the vulnerability for a seal failure. A critical safety bus with a full train of emergency core cooling systems remained unavailable for more than two hours during this plant transient. The licensee has estimated a conditional core damage probability of 2.8E-6 based on the conclusion that the emergency diesel generators remained operable. Contact: Thomas Koshy, REXB 301-415-1176 Email:_ @nrc.gov>
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Page Last Reviewed/Updated Wednesday, March 24, 2021