ML20248F945
| ML20248F945 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 03/28/1989 |
| From: | Leitch G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Murley T Office of Nuclear Reactor Regulation |
| References | |
| REF-PT21-89-028-000 PT21-89-028-000, PT21-89-28, NUDOCS 8904130266 | |
| Download: ML20248F945 (3) | |
Text
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c PHILADELPHIA ELECTRIC COMPANY _
. LIMERICK GENERATING STATION P. O. BOX A
. S AN ATOG A, PENNSYLV ANI A 19464 (215) 3274 200, EXT. 3000
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March 28, 1989 6......................
Docket'No. 50-352 License No. NPF-39 1
Dr. Thomas.E. Murley, Director
'I Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission l
Washington, D.C.
20555 l
SUBJECT:
Limerick Generating Station, Unit 1 10CFR21 Notification Control and Current Limit Boards
-for C&D: Power Systems _ Safeguard Battery Chargers
Dear Dr. Murley:
In accordance with 10CFR21, the following information is
~
being'provided in regard to'the latest revision of replacement circuit boards for safeguard battery chargers which do not' enable the chargers to provide required output current and voltage, l
Background
j On February 4, 1989, six new control boards and one new current limit board were. installed in Unit 1 Division II Charger 1BlD103 as part of preventive maintenance.
Circuit boards are replaced every five years based on a recommendation from'an
' independent testingJ1aboratory.
With the new circuit boards installed, it was not possible to obtain the proper float voltage
_i adjustment or current limit adjustment, nor was it possible to satisfactorily complete the battery surveillance test, which requires the charger to provide 300 amps output over an eight hour time period.
The maximum current output the charger was-able to supply was 250 amps.
Due to this problem, Maintenance reinstalled the original circgit boards, which restored the battery charger to an operable status.
C&D Power Systems were immediately notified and requested to supply the station with an expeditious response to'the parts discrepancy.
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On~ February'9, 1989, a deportability evaluation of this
. condition was initiated. 'On March 23, 1989, this evaluation
'l determined that the deviation was reportable in accordance with L10CFR21 as a defect.
It has also been determined 1that this condition does not exist on Unit 2.
.(
Specific Information l.
Name of individuals informing the Commission:
Verbal notification was to J. Linville, USNRC, on March.23, 1989 by J. W. Gallagher, Vice President, Nuclear Services Department.
2.
Identification of firm supplying the con".nent:
C&D. Power Systems
)
3043 Walton Rd.
Plymouth Meeting, PA 19462 l
3.
Identification of basic components which fails to comply:
i Control Board Part No.: MBC-1971-2-E Current Limit Board Part No.: MBC-1970-1-E-Both circuit boards are designed for use in Unit 1 battery chargers Model No. ARR 130K300.
1 4.
Nature of defect and safety hazard which could be created:
With the latest revision of the circuit boards installed, the battery charger current may be insufficient to supply station loads and restore the batteries to the fully charged state within the required eight hour time period.
However, this condition would become evident during surveillance testing as it was in this case with the 1BlD103 charger.
5.
The number and location of all components in use at the facility (Unit 1):
t In researching this concern, we have determined that the problem previously occurred in 1987.
On July 29, 1987, one (l? control board and one (1) current limit board were installed in Unit 1 l
Division I charger lAlD103 due to failure of the original board at that time.
In order to make the replac ment boards work, C&D power systems was contacied and a field change was made to the resistance of the charger circuit.
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Paga 3 The 1 AID 103 charger successfully passed its surveillance test at that-time and satisfied
' technical' specifications.
However, under Station practices, this-change should have been documented.
We are currently investigating the cause of this breakdown in configuration tracking.
6.
Corrective actions:
C&D Power Systems has now-provided. instructions 1 to change out a 600 ohm fixed resistor with a 500 ohm variable' resistor in the. charger circuitry to resolve the current and voltage adjustment.
A modification will be made to. install this 500 ohm resistor in all applicable safeguard battery chargers.-
Unit 2 battery chargers are.not affected, because they were manufactured at a later-date than the Unit 1 chargers and were supplied
.with a 500 ohm resistor.
7.
Advice to purchasers or licensees:
At'this time we'cannot provide any advice related to this defect since we have no information regarding the extent of the problem.
The foregoing information is as complete as we know the facts at this time.
We will provide more information on this equipment as appropriate following completion of our investigation into all aspects of the board replacement problems and their correction.
Should'you require any additional information, please do not hesitate to contact us.
Sincere Yl cc:
W. T. Russell, Administrator, Region I, USNRC T. J. Kenny, USNRC Senior Resident Inspector, LGS-1 l
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