U-601100, Amended Part 21 Rept Re Addl Damage to Div III Diesel Generator Discovered During Implementation of Corrective Actions.Initial Damage Reported on 870729.Reworking of Diesel Generator Complete.Damaged Exciter Leads Replaced

Amended Part 21 Rept Re Addl Damage to Div III Diesel Generator Discovered During Implementation of Corrective Actions.Initial Damage Reported on 870729.Reworking of Diesel Generator Complete.Damaged Exciter Leads Replaced

ML20235A217
Person / Time
Site:	Clinton
Issue date:	12/16/1987
From:	Hall D ILLINOIS POWER CO.
To:	Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
REF-PT21-87-218-000 PT21-87-218, PT21-87-218-000, U-601100, NUDOCS 8801120154
Download: ML20235A217 (4)

Text

- 1 U-601100

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ILLINO/S POWER OOMPANY llP CLINTON POWER STATION. P.O. BOX 678. CLINTON, ILLINOIS 61727

_0RITY ROUTI M December 16, 1987 b l Docket No. 50-461 b t 1

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Mr. A. B. Davis M-Q---9e Regional Administrator /rItc Region III U.S. Nuclear. Regulatory Commission 799 Roosevelt Road' Glen Ellyn, Illinois 60137

Subject:

AMENDED REPORT, 10CFR21 DEFECT 21-87-03: HIGH-PRESSURE CORE SPRAY, DIVISION III DIESEL GENERATOR EXCITER LEADS

Dear Mr. Davis:

On July 29, 1987, Illic.ois Power Licensing and Safety l Department received a Potential 10CFR21 Defect or l

Noncompliance Referral from the Illinois' Power Nuclear-Station Engineering Department concerning damaged High Pressure Core Spray (HPCS), Division III Diesel. Generator

Exciter Leads. Based on an evaluation of this matter, Illinois Power Company (IP) reported a 10CFR21 defect to the Commission by IP Letter U-601030 dated September 8, 1987.

Subsequently, IP notified the Commission of the revised l

scheduled completion date for corrective actions associated with this defect by IP Letter U-601078 dated. November 3, 1987. Letter U-601078 indicated that corrective actions scheduled to be completed during-the Fall Maintenance Outage -

planned for October 1987 were rescheduled to occur during the month of December 1987 due to schedule constraints. The corrective actions were satisfactorily completed on December 9, 1987. The purpose of the following amended 10CFR21 report is to identify _ additional damage.to the Division III Diesel Generator. This damage was discovered during implementation of corrective actions. Illin'ois Power Company is providing the following information to the Commission in accordance with the requirements of 10CFR, Part 21.21(b)(3).

(1) D. P. Hall, Vice President of Illinois Power Company, by means of this report.

(ii) The basic component involved in this reportable defect is the Division III Diesel Generator.

(iii) The Diesel Generator was built by Beloit Power Systems (now Louis-Allis). -

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1 U-601100 e L16-87 (12 - 16 )-LP 1A.120 (iv) The nature o2 the defect involved generator field leads which run through the generator shaft from the field rectifier assembly to the main field.

Diesel Generator exciter lead damage was confirmed at the point where the exciter leads exit the generator shaft. Chafing of the outer sleeve (cotton braid) was visually observed. The root cause of chafing was friction / rubbing by the i movement of the leads with the generator shaft. l This damage to the exciter leads resulted from the l absence of materials such as Room Temperature l Vulcanizing (RTV) to secure the leads in place inside the generator shaft and sharp edges within the shaft.

During replacement of the leads, additional damage to the exciter leads was identified. At the  ;

interfacing surfaces of the generator fan and the j pole-piece, the exciter lead was crushed and the protective tape and insulation damaged. This condition was identified at three fan to i pole-piece locations and appears to have occurred as a result of dislocating the lead during machine ,

i assembly.

IP has reviewed and evaluated the findings associated with the investigation of the defect / deficiency and has concluded that the matter represents a condition adverse to the safety of operation of the Clinton Power Station.

If this defect / deficiency had gone uncorrected, it could have resulted in failure of the Division III Diesel Generator and loss of the HPCS System ,

during an accident condition. These events could 1 affect the integrity and safe shutdown of the reactor. On this basis, the matter was evaluated to be reportable under the provisions of 10CFR21. .

(v) IP was notified of a potential defect / deficiency l in a letter received on July 23, 1987, from Energy j Systems, a Division of Pelham, Inc. 1 (vi) The Division III Diesel Generator is the only generator at the Clinton Power Station built by 1 Beloit Power Systems. The Division I & II Diesel Generators were built by Ideal Electric and have a '

different design.

(vii) On August 11, 1987, General Electric (supplier of  ;

the Division III Diesel Generator) inspected the l exciter leads and confirmed that damage existed at I the point where the exciter leads exit the generator shaft. Following the inspection, in a l l

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l meeting between IP, General Electric, and Stewart ,

l & Stevenson, it was agreed that IP would perform a j temporary repair of the damaged portion of the exciter leads. This decision was reached based on a discussion that similar repairs have been i successfully performed on generators of this type I at Illinois Power's fossil power plants, and by Stewart & Stevenson at commercial diesel power plants. The temporary repair on the exciter lead was completed on August 13, 1987, under Temporary Modification 87-130. The temporary modification was evaluated by the Nuclear Station Engineering '

Department to be adequate for continued operation of the Division III Diesel Generator until the 1 replacement of the exciter leads during the month l of December 1987.

General Electric provided a support to Illinois Power in performing the j necessary repair work under General Electric's q Nuclear Steam Supply System (NSSS) Warranty program.

1 General Electric issued Field Deviation Disposition Request LH1-4153 which provided a detailed rework plan to replace the damaged leads.

Rework of the Diesel Generator commenced on December 1, 1987 and was satisfactorily completed on December 9, 1987. All damaged exciter leads in the Division III Diesel Generator were replaced.

(viii) Letters of notification concerning this potential defecc/ deficiency were sent to purchasers /

licensees by Energy Systems Division on behalf of Beloit Power Systems.

Our evaluation of this reportable defect is available for your review at our offices. I trust this letter i provides sufficient information for your review and J assessment of this reportable defect. 1 i

Sincerely yours,

-~-~.

/

. . Hall Vice President j 1

1 RSF/ckc I

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U-601100

.- L16-87 (12-16 )-LP 1A.120 cc: USNRC Resident Office, V-690 Director of Inspection and Enforcement (3 copies)

NRC Clinton Licensing Project Manager INPO Records Center Illinois Department of Nuclear Safety Energy Systems Division l

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