ML20086K254
| ML20086K254 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 12/28/1983 |
| From: | Kemper J PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| SDR-107, NUDOCS 8401260372 | |
| Download: ML20086K254 (3) | |
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PHILADELPHIA ELECTRIC' COM PANY 2301 MARKET STREET P.O. BOX 8699 PHILADELPHIA. PA.19101 JOHN S. KEMPER DEC 281983 m..m.m m ENGINEE RtNG AND RESE ARCH Mr. Thomas E. Murley, Director United States Nuclear Regulatory Commission Office of Inspection and Enforcement, Region 1 631 Park Avenue King of Prussia, PA 19406
SUBJECT:
Significant Deficiency Report #107 I
Interim Report on Defective Agastat Relays Limerick Generating Station, Units 1 and 2 NRC Construction Permits Nos. CFPR-106 & 107
REFERENCE:
Telecon of November 29, 1983 P. K. Pavlides (PECo) to Walter Baunack (USNRC)
FILE:
QUAL 2-10-2 (SDR #107)
Dear Mr. Murley:
The reference telecon notified the USNRC of a potential 10CFR50.55e reportable condition.
This letter is provided as an interim report concerning the misoperation of Agastat GP relays at the Limerick Generating Station.
This problem is currently under investigation.
The defective Agastat GP relays at Limerick are undergoing analysis and testing by Philadelphia Electric Company.
We will be able to report the cause of this deficiency upon completion of this analysis.
It is expected that this investigation will be corapleted and our report submitted to you by March 30, 1984.
Sincerely,
$5Nf
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Attachment Copy to: Director of Inspection and Enforcement United States Nuclear Regulatory Commission Washington, DC 20555 S. K. Chaudhary, Resident NRC Inspector (Limerick)
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J' Limerick Generating Station Units 1 and 2 Significant Deficiency Report #107 Defective Agastat Relays Interim Report December 28, 1983 1.0 Introduction This report is intended as an interim report concerning a potential deficiency in the Agastat GP relays at the Limerick Generating Station (LGS).
The USNRC was notified of this potential 10CFR50.55e reportable condition in a telecon, dated November 29, 1983.
2.0 Description of Problem During pre-operational testing of the Residual Heat Removal (RHR) and Core Spray systems at LGS, several Agastat GP relays misoperated.
When the relay was de-energized, the normally closed contacts of these relays failed to close.
The cause of this malfunction is under investigation.
The failure has occurred in four (4) relays out of several hundred tested.
3.0 Analysis of Relay Failure The manufacturer of the Agastat relays, the Amerace Corporation, was contacted for their explanation.
According to Amerace, there was a manufacturing problem with relays produced between 1975 anc*.cagust, 1977.
The relays were shipped before the plastic bases had sufiicient time to " cure".
During post-shipment curing, the relay base was drawn towards the magnetic core assembly.
This shcrtened the gap between the movable contact arm retainer and the contact divider, thereby preventing closure of the contacts.
The manufacturer's term for this condition is known as " Post-Mold Plastic Shrinkage".
Philadelphia Electric is
' currently testing the defective relays to determine the exact cause of the failures observed.
4.0 Safety Implications The defective Agastat GP relays were discovered during pre-operational testing of the RHR and Core Spray systems at LGS.
A defective relay could adversely affect the operation of safety related equipment in these systems and other systems in which Agastat GP relays are provided.
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-5.0 Corrective Action The Agastat GP relays at LGS will be tested and inspected to determine: (1) the exact cause of relay misoperation; (2) if the relay is defective or improperly adjusted; and (3) if all of the Agastat GP relays at LGS have the potential for this problem.
The cause (s) of this deficiency will be determined upon completion of this analysis.
We expect to complete this investigation and submit our report by March 30, 1984.
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