BSEP-94-0482, Forwards Suppl Info Re EDG Reliability Program,As Requested
| ML20078Q401 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 12/12/1994 |
| From: | Lopriore R CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| BSEP-94-0482, BSEP-94-482, NUDOCS 9412220156 | |
| Download: ML20078Q401 (10) | |
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CP&L Caronne Power & Ught Company PO Box 10429 Southport NC 28461 December 12,1994 SERIAL: BSEP 94-0482 United States Nuclear Regulatory Commission ATTENTION: Document Control Desk Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS.1 AND 2 DOCKET NOS. 50-325 & 50-324/ LICENSE NOS. DPR-71 & DPR 62 SUPPLEMENTAL INFORMATION REGARDING BNP EMERGENCY DIESEL GENERATOR REllABILITY PROGRAM Gentlemen:
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By letter dated October 28,1994, the NRC staff requested supplemental information regarding the Emergency Diesel Generator (EDG) Reliability Program at Carolina Power &
Light Company's Brunswick Steam Electric Plant, Units 1 and 2. Enclosure 1 provides the supplementalinformation requested by the NRC staff. Enclosure 2 provides the outage summary update for the emergency diesel generators at the Brunswick Plant, as requested by the NRC staff.
j Please refer any questions regarding this letter to Mr. M. A. Turkal (910) 457-3066.
Sincerely,
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R. P. Lopriore Manager - Regulatory Affairs Brunswick Nuclear Plant KAH/
Enclosures
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Mr. S. D. Ebneter, NRC Regional Administrator, Region 11 Mr. P. D. Milano, NRC/NRR Senior Project Manager Brunswick Mr. C. A. Patterson, NRC Senior Resident inspector - Brunswick The Honorable H. Wells, Chairman - North Carolina Utilities C;mmission l
9412220156 941212 PDR ADOCK 05000324 P
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ENCLOSURE 1 BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 NRC DOCKET NOS. 50-325 & 50-324 OPERATING LICENSE NOS. DPR-71 & DPR-62 RESPONSE TO NRC REQUEST FOR SUPPLEMENTAL INFORMATION EMERGErJCY DIESEL GENERATOR RELIABILITY PROGRAM Backaround On August 31,1994, Carolina Power & Light Company (CP&L) and the NRC staff met to discuss the status of ongoing electrical distribution system (EDS) enhancement projects.
During this meeting, CP&L discussed the actions taken to improve the emergency diesel generator (EDG) reliability at the Brunswick Nuclear Plant (BNP). The NRC staff, by letter dated October 28,1994, has requested supplemental information be provided regarding the EDG preventive maintenance program and the resultant improvement in overall EDG reliability. The NRC staff specifically requested 1) a brief description of the EDG reliability program, and 2) the associated improvements in the maintenance training and in the tooling used on the EDGs, with specific emphasis on the differences from the previous program. Additionally, the NRC staff requested a list summarizing the EDG outages, durations, and causes since the dual unit shutdown in April 1992.
The NRC staff requested that this supplementalinformation be provided within 45 days of the date of the October 28,1994 letter. This enclosure provides the information requested by the NRC staft regarding the BNP EDG reliability program and improvements made in the reliability of the EDGs. Enclosure 2 provides the emergency diesel generator outage summary information requested by the NRC staff.
Prior to 1992, the Brunswick Nuclear Plant did not have an integrated, focused effort for improving the reliability of the emergency diesel generators. Beginning in 1992, an initiative was undertaken to fully understand and address the fundamentalissues involved with the EDG reliability concerns. The reliability improvaments undertaken included 1) completion of significant repairs and upgrades to the EDGs,2) Preventive Maintenance Program improvements, and 3) improvements in maintenance planning and execution.
Reoairs and Uparades Beginning in 1992, the BNP EDGs have received significant repairs and upgrades, including:
e Flex Drive Refurbishment. Dynamically balanced engine flex drive assembly, as necessary, to reduce torsional vibration and increase reliability of the flex drive assembly, engine driven pumps and engine crankshaft.
l Tachometer Dioital Speed Controller Uoorade. Provided more reliable and accurate actuation of speed sensing contact switches which control generator field flashing, generator frequency permissives, and shutdown of starting air.
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'e Crankshaft Power Cylinder Refurbishment. Implemented a program to replace / refurbish main bearings, connecting rod bearings, piston rings, pistons, cylinder heads, and cylinder liners for increased engine reliability and performance. Program completion status is as follows: EDG#1 - 100%,
EDG#2 - 6%, EDG#3 - 50% and EDG#4 - 50%.
Diesel Startina Air Control Air Drvers. Installed high capacity desiccant
'I dryers in the control air system to ensure high quality air to system components to reduce corrosion related problems.
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Rotafoam Rectacement and Enaine Cleanina. Replaced oil laden rotafoam fire barrier around diesel foundation and cleaned oil trough under the engine to reduce potential fire hazards.
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Lube Oil Bvoass Filter Media Uoorade, improved particulate filtration to approximately 0.5 micron to decrease weir and increase reliability of engine bearings and shaft journals.
e Jacket Water Heater Pumo Rebuild and Motor insoections. Resolved repetitive mechanical sealleakage problems, as necessary. Motor inspections are on-going to determine optimal motor bearing lubrication requirements to further ensure reliable operation.
Enaine Governor Refurbishment and Synthetic Oil Substitution. Provided increased governor system reliability through replacement of degrading components. Use of synthetic oil reduces the production of varnish caused by temperature induced oil degradation. Per the governor manufacturer, the major cause of governor malfunctions is dirty oil.
l Fuel Pumo, Iniector and Pumo-to-Iniector Fuel Line Rectacemarlt. Provided improved cylinder pressure balancing through consistent delivery of fuel to each cylinder.
e Enaine Gasket Uoarades. On-going effort to reduce nuisance oilleaks from various gasket covers on the engine implemented the use of improved seal materials (VITON) to increase seat life for critical applications and to enhance engine reliability.
e Generator Brush Riaaina Refurbishment. Corrected several original installation errors and initiated a preventative maintenance route to periodically inspect and clean the brush rigging of accumulated carbon, t
These actions improve generator reliability by significantly reducing the potential of receiving a ground in the generator exciter circuitry.
l Additional significant repairs and upgrades were made to EDG#1 while troubleshooting a wiped cranir : aft main bearing in 1992. Engine repairs / improvements included crankshaft straightenint
' realignment, polishing of crankshaft journals, engine driven jacket water pump realignment, engine driven lube oil pump replacement, and generator stator realignment. Performance of these activities significantly reduced engine driven pump vibration and improved overall engine reliability.
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1 Preventive Maintenance Proaram Imorovements Beginning in 1992, significant improvements were made in the BNP EDG Preventive Mainte.iance Program. These improvements included establishment of an EDC Reliability Program and Nordberg Diesel Owners Group and improvements in training and tooling.
Plant Performance Procedure (PPP)-17, Emergency Diesel Generator Reliability Program, is the controlling procedure for the EDG Reliability Program. The program is intended to ensure EDG reliability is monitored and maintained at, or above the selected Station Blackout (SBO) EDG Reliability Target Level. The procedure specifies EDG Reliability Program elements intended to ensure established station EDG reliability programs are consistent, and EDG performance is monitored in accordance with Regulatory Guide 1.155, " Station Blackout," Regulatory Guide 1.9, Revision 3 (working draft), " Selection, Design, Qualification, Testing, and Reliability of Diesel Generator Units Used as Class 1E Onsite Electric Power Systems at Nuclear Power Plants," and NUMARC 87-00, Appendix D, Revision 1, " Guidelines and Technical Bases for NUMARC Initiatives Addressing Station Blackout at Light Water Reactors,". The procedure also specifies actions to be taken if reliability performance indicators for one or more EDGs meet or exceed station reliability trigger values. The program monitors 18 parameters per EDG. The EDG Reliability Program includes:
o Collection and review of engine trend data, o
Collection and review of fuel oil trend data, e
Vibration spectral analysis, e
Reliability and availability data trending versus established corporate goals.
e Identification and prioritization of EDG improvements / corrective actions.
e Establishment of an EDG Reliability Committee The EDG Reliability Committee has proven to be an effective element in the EDG Reliability Program. The committee is responsible for:
e Review of effectiveness of EDG Reliability Program.
e Review of EDG reliability and performance, Performing a comprehensive review of EDG Reliability Program if the 50 and e
100 demand trigger values are exceeded, and e
Identifying, prioritizing, and f acilitating EDG improvements / corrective
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Support of EDG Reliability Program in any other manner deemed appropriate by plant management.
The Nordberg Diesel Owners Group has been an effective means of resolving parts issues, obtaining engineering reviews for emerging issues, a forum for discussion of failures and sharing experiences, assisting in the shift from a preventive to a predictive maintenance program, and has provided a valuable resource for training engineering and craft personnel.
Training and tooling improvements have played a significant role in the EDG reliability improvements. A qualification card program and/or specialized training were provided to improve engineering and craft skills and efficiency, including:
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'e System engineer certification e
Diesel craft certification e
Nordberg-specific diesel training BETA monitor analysis / diagnostic instruction e
Bearing training e
Voltage regulation training e
Woodward governor training e
Diesel engine analysis training e
Instrument and controls class for mechanics in addition, an exchange program with Duke Power Company and the governor vendor (Woodward) was established to assist in major overhaul activities and provide additional opportunities for training.
Tooling improvements have been made for testing, inspection, and maintenance activities.
Specific tooling-related improvements include:
e Cylinder liner pull-out toole e
Stud tensioning tools e
Lift check and bearing lifting devices e
Cylinder head rebuild stand e
Piston gap and ring compressor tools e
Fuel injector test equipment e
Assignment of a diesel head shop for workspace and special tool control Maintenance Plannina/ Execution Maintenance planning and execution have resulted in reduced backlogs and improved operational performance. These results have been obtained through improvements in both maintenance process and philosophy. Specific improvements include: 1) the integration of a cohesive, focused EDG team consisting of maintenance craft and system and component engineers, 2) improvement in operations work control and shift support for clearances and system operation,3) use of dedicated QC inspectors for EDG outage support, and
- 4) continued planning and execution of preventive and corrective maintenance activities during elective system outage windows.
Summary improvements made in EDG reliability at the Brunswick Nuclear Plant have resulted in increased confidence in EDG maintenance capability within existing LCO times, a 50 percent reduction in the EDG maintenance backlog from 1992, a reliability index above the target value of 97.5% and below trigger values for the last 20,50, and 100 start / load demands, and, with the exceptio:1 of the July,1994 voltage regulator issue, no start or load demand failures since November 1992. These results have been gained through an improvement initiative which addressed the underlying root causes of the EDG reliability issues through 1) the completion of significant repairs and upgrades to the EDGs,2)
Preventive Maintenance Program changes, and 3) improvements in maintenance planning and execution.
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ENCLOSURE 2 BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 NRC DOCKET NOS. 50-325 & 50 324 OPERATING LICENSE NOS. DPR-71 & DPR-62 RESPONSE TO NRC REQUEST FOR SUPPLEMENTAL INFORMATION EMERGENCY DIESEL GENERATOR RELIABILITY PROGRAM OUTAGE
SUMMARY
DATA EMERGENCY DIESEL GENERATOR NUMBER 1
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OUT OF SERVICE REACTOR STATUS OUT OF SERVICE OUTAGE CODE START DATE (AT POWER OR DURATION SHUTDOWN)
(HRS) 6/29/92 SHUTDOWN 267.4 C
7/13/92 SHUTDOWN 144.5 P/C 8/4/92 SHUTDOWN 8.9 P/C 9/17/92 SHUTDOWN 2495.8 P/C 11/13/93 SHUTDOWN 13.15 C
12/6/93 SHUTDOWN 16.18 P/C 1/21/94 SHUTDOWN 9.13 P/C 8/15/94 AT POWER 41.68 P/C OUTAGE CODES:
P - Preventive Maintenance C - Corrective Maintenance T - Test I
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l EMERGENCY DIESEL GENERATOR NUMBER 2
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OUT OF SERVICE REACTOR STATUS OUT OF SERVICE OUTAGE CODE START DATE (AT POWER OR DURATION SHUTDOWN)
(HRS) 8/19/92 SHUTDOWN 297.8 P/C 2/8/93 SHUTDOWN 138,4 P/C 5/3/93 SHUTDOWN 87.4 P!C 6/23/93 SHUTDOWN 107.4 P/C 7/31/93 SHUTDOWN 2.9 P/C 8/1/93 SHUTDOWN 98.75 P/C 10/20/93 SHUTDOWN 25.3 P/C 12/13/93 SHUTDOWN 18.25 P/C 7/9/94 AT POWER 17.45 C
7/18/94 AT POWER 13.83 C
8/22/94 AT POWER 15.42 P/C i
OUTAGE CODES:
P - Preventive Maintenance C - Corrective Maintenance l
T - Test i
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1 EMERGENCY DIESEL GENERATOR NUM8ER 3 OUT OF SERVICE REACTOR STATUS OUT OF SERVICE OUTAGE CODE START DATE (AT POWER OR DURATION SHUTDOWN)
(HRS) 7/17/92 SHUTDOWN 258.65 P/C 9/6/92 SHUTDOWN 151.35 P/C 1/21/93 SHUTDOWN 342.23 P/C 3/1/93 SHUTDOWN 3.39 P/C 4/1/93 SHUTDOWN 14.35 P/C 9/27/93 AT POWER 13.62 P/C 10/25/93 AT POWER 21.2 P/C 11/11/93 AT POWER O.9 C
4/11/94 SHUTDOWN 77.58 P/C 4/27/94 SHUTDOWN 190.68 P/C 8/29/94 AT POWER 13.43 P/C OUTAGE CODES:
P - Preventive Maintenance C - Corrective Maintenance T - Test E2-3 l
EMERGENCY DIESEL GENERATOR NUMBER 4 OUT OF SERVICE REACTOR STATUS OUT OF SERVICE OUTAGE CODE START DATE (AT POWER OR DURATION SHUTDOWN)
(HRS) 11/4/92 SHUTDOWN 21.2 C
11/30/92 SHUTDOWN 685.9 P/C 1/2/93 SHUTDOWN 393.7 P/C 8/9/93 AT POWER 6.25 P/C 11/11/93 AT POWER 1.98 C
11/12/93 AT POWER 2.7 C
11/29/93 AT POWER 17.35 P/C 3/21/94 AT POWER 5.48 C
4/19/94 SHUTDOWN 110.67 P/C OUTAGE CODES:
P - Preventive Maintenance C - Corrective Maintenance T - Test I
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ENCLOSURE 3 BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND 2 NRC DOCKET NOS. 50-325 & 50-324 OPERATING LICENS5i NOS. DPR-71 & DPR-62 LIST OF REGULATORY COMMITMENTS The following table identifies those actions committed to by Carolina Power & Light Company in this document. Any other actions discussed in the submittal represent intended or planned actions by Carolina Posver & Light Company. These actions are ~
described to the NRC for the staff's information and are not regulatory commitments.
l Please notify the Manager-Regulatory Affairs at the Brunswick Nuclear Plant of any questions regarding this document or any associated regulatory commitments, i
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Committed Commitment date or l
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