ML20199F925

Ack Receipt of Informing NRC of Steps Taken to Correct Violations Noted in Insp Repts 50-352/98-05 & 50-353/98-05

ML20199F925
Person / Time
Site:	Limerick
Issue date:	01/11/1999
From:	Jimi Yerokun NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:	Rainey G PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
References
50-352-98-05, 50-352-98-5, 50-353-98-05, 50-353-98-5, NUDOCS 9901220092
Download: ML20199F925 (2)

See also: IR 05000352/1998005

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January 11, 1999 1

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Mr. i. Rainey, President

PECO Nuclear

Nuclear Group Headquarters

i Correspondence Control Desk

l P. O. Box 195

Wayne, PA 19087-0195

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SUBJECT: NRC INSPECTION REPORT NO. 50-352/98-05 AND 50-353/98-05- REPLY l

Dear Mr. Rainey:

This letter refers to your September 8,1998 correspondence, in reponse to our

August 7,1998 letter.

Thank you for informing us of the corrective and preventive actions documented in your

letter. These actions will be examined during a future inspectic n of your licensed program.

Your cooperation with us is appreciated.

Sincerely, i

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Jimi T. Yerokun, Acting Chief l

Engineering Programs Branch

Division of Reactor Safety

Docket No. 50-352;50-353

cc:

J. J. Hagan, Vice President, Nuclear Station Support

G. Edwards, Chairman, Nuclear Review Board and Director - Licensing

J. von Suskil, Vice President - Limerick Generating Station

M. P. Gallagher, Plant Manager, Limerick Generating Station

T. Moore, Manager, Experience Assessment

Secretary, Nuclear Committee of the Board

Commonwealth of Pennsylvania

210018 i

9901220092 990111

PDR ADOCK 05000352

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Mr. G. Rainey 2

Distribution:

Region i Docket Room (with concurrencen

W. Lanning, DRS

W. Ruland, DRS

J. Yerokun, DRS

A. Lohmeier, DRS

C. 6%3i LL. DRP

D. Florek, DRP

R. Junod, DRP

NRC Resident inspector

Nuclear Safety information Center (NSIC)

PUBLIC

G. Shear, OEDO

R. Capra, PDl-2 N3R

B. Buckley, PL 1-2, NRR

M. Thadani, PD 1-2, NRR

R. Correia, NRR

M. Campion, ORA

DOCDESK

inspection Program Branch, NRR (IPAS)

DRS File

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DOCUMENT NAME: G:\ PROGRAMS \LOHMElER\ LIM 9805. REP

T4 teceive a copy of this document. Indicate in the box: "C" = Copy without attachment / enclosure "E" = Copy with attachrnent/ enclosure "N" = No

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i OFFICE Rl/DRS fy l ( Rl/DRf,.f3 Rl/DRS IWORA l l

NAME ALohmeier / Q{l CCo; Vgf( ' \ JYerokun @7 M

DATE 01/06/99 U\ 01/[/99 01/sh/99 V N 01/ /99

OFFICIAL RECORD COPY

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PECO NUCLEAR n co c,em ,co ,an,

A Unit of PECO Energy M,x23OO i

sanatoga. PA 19464 0920

610 718 3000 / Faz 610 718 3008 ,

Pager 1800 672 2285 #02 71

Internet address gvonsuskilia'gwco energyenr.,

10 CFR 2.201

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September 8,1998

Docket Nos. 50 352

50-353

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License Nos. NPF-39

NPF-85

U.S. Nuclear Regulatory Commission '

Attn.: Document Control Desk

Washington, DC 20555

SUBJECT: Limerick Generating Station, Units 1 and 2

Reply to a Notice of Violation

NRC Inspection Report 50-352/98-05 and 50-353/98-05

Attached is PECO Nuclear's reply to a Notice of Violation for Limerick Generating Station

(LGS) Unit 1, that was contained in your letter dated August 7,1998. The Notice identified one  !

violation, with two examples, where conditions adverse to quality were not promptly identified

and corrected. The attachment to this letter provides a restatement of the violations followed

by our reply.

If you have any questions or require additional information, please contact us.

Very truly yours,

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$50k

Enclosure

Attachments

cc: H. J. Miller, Administrator, Region I, USNRC w/ attachments

A. L. Burritt, USNRC Senior Resident inspector, LGS "

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Atttchment

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S:ptamb:r 8,1998

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Page 1 of 3

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REPLY TO A NOTICE OF VIOLATION

Restatement of the Violations

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During an NRC inspection conducted between June 1,1998, and June 24,1998, a violation of

NRC requirements was identified. In accordance with the General Statement of Policy arid

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Procedure for NRC Enforcement Actions, NUREG-1600, the violation is listed below:

A. 10 CFR 50, Appendix B, Criterion XVI, requires, in part, that: " Measures shall be

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established to assure that conditions adverse to quality, such as failures, malfunc; ions,

deficiencies, deviations, defective material and equipment and nonconformances . ire

promptly identified and corrected."

l Contrary to the above, the following conditions adverse to qualit, .ce not promptly

l Identified and corrected.

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1.

Defective equipment (an incorrectly wired current transformer) in the supply l

circuit breaker of load center 124B was not identified and corrected, and on l

March 22,1998 the breaker tripped unexpectedly and de-energized all the loads I

supplied by the load center. PECO was aware of potential wiring errors  !

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affecting the circuit breakers used at Limerick since November 1996 based on

industry operating experience. PECO had failed to revise the pendic

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calibration procedure, which could have identified the incorrectly wired current .

i transformers and prevented the event.

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2. Deficiencies (age-related failures) in Agastat relays in three panels (OA, OB,

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and OC-C124) were not identified and corrected. Due to higher panel

temperatures, the continued use of these Agastat relays beyond their

appropriate service life led to higher age-related failures, including the l

April 4,1998, event in which the B train of the control room emergency fresh air  ;

supply (CREFAS) system did not actuate. On June 19,1998, several such  !

relays remained in service, considerabiy beyond their calculated service lives.

This is a Severity Level IV Violation (Supplement 1).

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Attachment I

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Dock;t Nos. 50-352 and 50-353

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Sept:mb;r 8,1998

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Reply to Violation A

AoQsion of the Violation

PECO Energy acknowledges the violation.

Reaso s for the Violations

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Both ext uples cited in the violation were caused by untimely completion of corrective actions

for self-ic antified problems.

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The reason for example (1) of the violation, as stated in Licensee Event Report 1-98-005, Rev.

0, for Limerick Generating Station (LGS), Unit 1, is described below.

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The 124B load cen'er tripped due to improper wiring of the current transformer (CT)

circuit for one of the load center feeder breaker's protective re!ays. This improper

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i configuration causec' the feeder breaker (124B-62) to trip prematurely under normal l

plant loading. The improperty wired CT circuit was supplied in that configuration by the

manufacturer, however, station calibration procedures were less than adequate to

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!dentity this situation. An Operating Experience item, related to CT configuration l

causing a premature creaker trip, was reviewed in November 1996, determined to be

app!!c.able, and the procedure revision action item was created. The CT configuration  !

issue m3 reviewed again in 1997 when the vendor issued a 10CFR Part 21 notice for l

the same concem. The target breaker calibration procedure had not been revised

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when it was used during breaker maintenance four days prior to this event.

The reason for example (2) was work prioritization such that the review of Agastat relay service

conditions and the planned relay replacements in the OA,08, and OC-C124 panels were not

completed in a timely manner. The OA, Otl, and OC-C124 panels are designated as a mild

environment in design documents. Relay replacement dates were therefore established, using

PECON procedures, commensurate with the safety significance of the relays and the expected

service environment. In 1997, failure data indicated that the service environment in the OA,  !

08, and OC-C124 p anels may be contributing to a higher than expected failure rate. A service

environment and relay failure study was initiated for the subject panels and other panels. This

resulted in a recommendation that Agastat relays be established as a Maintenance Rule

Program (a)(1) system. Corrective actionT were initiated that included accelerated

replacement of certain relays, including specific relays in the OA, 08, and OC-C124 panels.

The data analysis re.vealed that the higher than expected Agastat relay failure rate in these

panels was caused by localized heating effects. The majority of relays that failed were either

at the top of the prnel (highest temperature in the panel) or were near energized instrument

power supplies.

Corrective Actions Taken and Results Achieved

The corrective actions for the load center breaker issue (example (1)) are described in LER 1-

98-005. An Engineering analysis was ccmpleted on March 26,1998, that determined that

there was no adverse impact on t5e operability of load center breakers susceptible to the same

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Dockst Nos. 50-352 and 50-353

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Page 3 of 3

' CT configuration concern. The load center breaker calibration procedure (M-C-700-230) was

revised on April 4,1998. No additionalload center breaker trips, due to CT configuration, have

occurred sirice March 22,1998.

Completed corrective actions for the Agastat relay issues (example (2)) are described below.

To date,85 % of the Unit 1 and Common (oldest) Agastat relays in the subject panels (OA,08,

and OC-C124) have been replaced. All of the remaining normally energized relays (including

Unit 2) are scheduled for replacement prior to the end of 1998. An Engineering analysis was

completed on August 4,1998, and documented the acceptability of continued use of Agastat

relays in the OA, OB, and OC-C124 panels up to the time of their scheduled replacement.

Engineering has evaluated the status of th'e Limerick Agastat relay failure analysis and

replacement program, including an assessment of the technicalissues raised during the June

1998 NRC inspection. Corrective actions include appropriately adjusting relay replacement 4

due dates and frequencies, maximizing the planning and execution effort for all relays, and I

applying lessons leamed to the Unit 2 panels with normally energized relays. Engineering

provided a presentation to station management in August,1998 on the status of the Agastat

relay evaluation and replacement program.

Corrective Actions to Avoid Future Noncompliance

As of August 28,1998, all but three (3) load center breakers had been tested with the revised

test. The remaining three (3) are scheduled to be completed by December 1,1998.

Agastat relay failures and service life estimates are being tracked and evaluated on an

ongoing basis and the relays are replaced on an ongoing basis. The results of the in-plant

data analysis are being incorporated into the Preventive Maintenance program for each Q-

listed Agastat relay. Expected service lives are being adjusted based on service environment

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' effects, such as localized heating. The Agastat relay system Maintenance Rute Program (a)(1)

action plan will be used to restore performance to (a)(2) status.

pate When Full Compliance was Achieved

Full compliance was achieved on August 4,1998, when Engineering analyses were completed

that supported continued operation in light of the identified load center breaker CT

configuration and Agastat relay service life issues.

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