ML20052C108

Interim Deficiency Rept Re Improper Application of Emergency Diesel Generator Current Transformers Mfg by Westinghouse. Replacement of Transformers Expected by 821130

ML20052C108
Person / Time
Site:	Washington Public Power Supply System
Issue date:	04/02/1982
From:	Root R WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Faulkenberry R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
10CFR-050.55E, 10CFR-50.55E, NUDOCS 8205040375
Download: ML20052C108 (3)

Text

Docket Nos. 50 l+60/513 l

50.55(e) Report Washington Public Power Supply System P.O. Box 968 3000GeorgeWashingtonWay Richland, Washington 99352 (509)372-5000 April 2,1982 Ej G0-1 0119

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Nuclear Regulatory Commission g

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M 1450 Maria Lane, Suite 210 N

Walnut Creek, California 94596 g_

Attention:

Mr. R. H.'Faulkenberry 1_

f, 3.lIl Chief, Reactor Construction 4

Projects Branch 1JO

Subject:

NUCLEAR PROJECTS 1 AND 4

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DOCKET N05. 50-460 AND 50-513 p

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REPORTABLE CONDITION 10CFR50.55(e)

EMERGENCYDIESELGENERATORCURRENTTRANSF0i{RSdy;

Reference:

1)

Telecon ME Rodin, Supply System to J

PP Narbut dated November 13, 1981 3

2)

G0-1-81-417, DW Mazur to RH Faulkenberry dated December 15, 1981.

In reference 1) the Supply System informed your office of a reportable deficie icy under 10CFR50.55(e) and reference 2) was an interim report on the subject condition.

Attachment "A" includes a statement of the identified condition and a brief description of our planned and ongoing actions to correct the identified deficiency. As you will see in our discussion under Corrective Action, we have selected a supplier for the defective current transformer; however, we are still unable to provide a firm date by which all actions including installation of the new current transformer will be completed.

Therefore, the Supply System will continue to provide your office with interim status reports on a quarterly basis.

If you havegquestions or desire further information, please advise, e

R. W. Root Acting Program Director RWR:MER:Im Attachment cc: CR Bryant BPA/399 EW Edwards /860 V. Mani/897 V. Stello, Director of Inspection, NRC A. Toth, NRC

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8205040375 820402 f

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o ATTACHMENT A WNP-1/4 DOCKET N05. 50-460 AND 50-513 REPORTABLE CONDITION PER 10CDR50.55(e)

EMERGENCY DIESEL GENERATOR CURRENT TRANSFORMERS BACKGROUND The Supply System purchased Emergency Diesel Generators, two per plant, from Transamerica Delaval. The electrical generation equipment portion of the package was subcontracted to Parsons Peebles - Electric Products, Inc., who in turn subcontracted a portion of their scope of work to Portec, Inc. Parson Peebles has reported under the requirements of 10CFR50 Part 21, a deficiency associated with specific current transformers, which are described in detail under " Description of the Deficiency", which were used in the manufacturing of the Emergency Diesel Generators.

The equipment involved in this report was designed, manufactured, and tested by Portec, Inc., Electric Products Controls Division; Highland, Illinois 62244, during the period from 1975 to 1979.

Following receipt of the 10CFR part 21 notification from Transamerica Delaval, Supply System Contract 53, it was determined that this deficiency was reportable under the requirements of 10CFR50.55(e).

DESCRIPTION OF THE DEFICIENCY The design deficiency consists of an improper application of Westinghouse Type ECT current transformer, Part No. 7524A68G16, in the paralleling circuit of the static exciter voltage regulatory system.

As presently applied, this transformer will operate outside of its rated temperature rangt. whenevertheambiegttemperatureatitslocationinthegenerator control panel exceeds 30 C.

While no immediate malfunction of the equip-ment will result from such operation, the transformer will age thermally at an excessive rate leading to its premature failure at around 14% of its normal life expectancy.

1 SAFETY IMPLICATIONS Although parallel operation of the Class lE design generator systems is not included amoung the postulated functions during the DBE, it is routine-ly performed as a part of mandatory exercises of the safety related systems (Regulatory Guide 1.108) during which the current transformer failure would result in a loss of the systems capability to share the reactive load. However, a potential hazard exists that a severe thermal degradation of this transformer may go unnoticed, its failure impending, when the paralleling circuit is inactive. Since the current transformer cannot be de-energized, it remains under load at all times when the generator is loaded.

Thus, its thermal degradation progresses even when its secon-dary winding output is short circuited and the paralleling deactivated.

Ultimately, the current transformer failure may result in a failure of the diesel generator system to fulfill its Class IE mission due to a line to ground fault, in the worst case, or it may cause different levels of degradation of adjacent components of the Class IE circuits.

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i CORRECTIVE ACTION The Supply System and UE&C Engineering both ' agree with the Parsons Peebles recommendation that the Westinghouse current transformers be replaced by an interchangeable current transformer manufactured by Norlake Manufacturing Company of Elyria, Ohio.- The Norlake current transformer model CD 1408 has been selected to replace the Westinghouse

- current transformer and is currently undergoing qualification testing.

Completion of the qualification testing, procurement and installation of the replacement parts is expected to be completed by November 30, 1982..

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