ML17325A924

Responds to NRC 880823 Ltr Re Violations Noted in Insp Repts 50-315/88-16 & 50-316/88-18.Corrective Actions:Procedures Revised to Require Each Shift to Log Ground Voltage Indications When Ground Exists

ML17325A924
Person / Time
Site:	Cook
Issue date:	09/21/1988
From:	Alexich M INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	Davis A NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
AEP:NRC:1060G, NUDOCS 8809290056
Download: ML17325A924 (6)

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.~SSZON NBR:8809290056 DOC.DATE: 88/09/21 NOTARIZED: NO DOCKET FACZL:50-315 Donald C. Cook Nuclear Power Plant, Unit 1, Indiana S 05000315 50-316 Donald C. Cook Nuclear Power Plant, Unit 2, Indiana a 05000316 UTH.NAME AUTHOR AFFILIATION XICH,M.P. Indiana Michigan Power Co. (formerly Indiana & Michigan Ele CZP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

SUBJECT:

Re'sponds to 50-315/88-16 NRC 880823 ltr re violations noted in Insp 50-316/88-18.Corrective actions:

Repts DISTRIBUTION CODE: IE01D COPIES RECEIVED:LTR TITLE: General (50 Dkt)-Insp Rept/Notice of

/ ENCL / SIZE:

Violation Response NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ZD CODE/NAME LTTR ENCL PD3-1 PD 1 1 STANG,J 2 2 INTERNAL: AEOD 1 DEDRO 1 1 NRR MORISSEAUiD 1 NRR/DLPQ/PEB 11 1 1 NRR/DLPQ/QAB 10 1 NRR/DOEA DIR 11 1 1 NRR/DREP/EPB 10 1 NRR/DREP/RPB 10 2 2 NRR/DRIS DIR 9A 1 NRR/PMAS/ILRB12 1 1 NUDOCS-ABSTRACT 1 OE LIEBERMANiJ 1 1 OGC/HDS1 1 'EG FILE 02 1 1 RES/DSIR DEPY 1 ILE 01 1 1 E AL: LPDR 1 1 NRC PDR 1 1 NSIC 1 1 TOTAL NUMBER OF COPIES REQUIRED: LTTR 23 ENCL 23

indiana Michigan Power Company P.O. Box 16631 Cofumbus, OH 43216 INDIANA NlCHIGAN POWER AEP:NRC:1060G Donald C. Cook Nuclear Plant Units 1 and 2 Docket Nos. 50-315 and 50-316 License Nos. DPR-58 and DPR-74 NRC INSPECTION REPORT NOS. 50-315/88016 (DRS)

AND 50-316/88018 (DRS)

U.S. Nuclear Regulatory Commission Document Control Desk Washington, D. C. 20555 Attn: A. B. Davis September 21, 1988

Dear Mr. Davis:

This letter is in response to Mr. J. J. Harrison's letter dated August 23, 1988, that forwarded the report on the routine safety inspection conducted by members of your staff. This inspection was conducted from July 11-15, 18-22, 27 and August 8, 1988, on activities at the Donald C. Cook Nuclear Plant Units 1 and 2. The Notice of Violation attached to Mr. Harrison's letter identified one violation. This violation is addressed in the attachment to this letter.

This document has been prepared following Corporate procedures which incorporate a reasonable set of controls to ensure its accuracy and completeness prior to signature by the undersigned.

Sincerely, M. P. Al ich Vice Pre ident MPA/eh Attachment cc: D. H. Williams, Jr.

W. G. Smith, Jr. - Bridgman R. C. Callen G. Bruchmann G ~ Charnoff NRC Resident Inspector - Bridgman 8809290056 8809'21 PDR ADQCy, 05000315 G

to AEP:NRC:1060G Page 1 RESPONSE TO NRC INSPECTION REPORT 50-315/88016; 50-316/88018 Violation "10 CFR 50, Appendix B, Criterion XVI, as implemented by the D. C.

Cook Operations Quality Assurance Program, Section 1.7.16, requires that conditions adverse to quality be promptly corrected and action taken to preclude repetition of significant conditions adverse to quality.

Contrary to the above, a negative DC ground has existed on the Unit: 1 250 VDC normally ungrounded "CD" battery since January 2, 1988. Action taken to preclude repetition was incomplete in that a comprehensive technical evaluation was not prepared to assure that the margin of safety had not been reduced for continued operations of'afety-related equipment."

Corrective Action Taken and Results Achieved At 0500 on 12/18/87, a ground was annunciated for the 250 VDC Bus CD. At that time the operators commenced actions to locate the ground in accordance with procedure 1-OHP 4021,082.012 "Location 250 VDC Grounds." The actions that were allowed with the unit at power were completed, but were unsuccessful in locating the ground. Since the ground on one polarity presented no operational problem, it was decided to continue power operation with the intent of 1ocating and repairing the ground when the unit was shut down for other reasons. This was considered acceptable since the ungrounded 250 VDC system was designed to allow continued operation with a ground, on one polarity and due to the design of the ground detection circuitry, which limits ground fault current to approximately 49 milliamps.

During a one-day outage on March 26, 1988, additional attempts were made to locate the ground, however these attempts were unsuccessful.

On July 28, 1988, during inspection activities for routine safety inspection 50-315/88016 and 50-316/88018, the inspector raised concern over the lack of a documented safety evaluation specifically for continued plant operation with a single polarity ground on the CD bus of the 250 VDC system. In response to this concern a safety evaluation was completed on August 4, 1988, This evaluation documented the position that a single pole ground would not adversely affect the operability of electrical equipment nor to hEP:bRC:10600 Page 2 preclude continued safe operation of the plant. in response to a subsequent HRC inquiry, it was also confirmed that, if a second ground were to result in a blown fuse, the operators would be alerted to the inoperability status cf vital equipment via annunciators or indicating lights.

The unit was shut down on September 7, 1988, due to excessive RCS leakage. After t'no shutdown, testing was done and a g-ound was found on a feedwater heater level s~itch. The level switch was subsequently repaired to =emove the ground.

Corrective Action to be Taken to Avoid Further Violati.ons Procedure OHP 4021.082.012 in both units was revised on August 10, 1988, to require each shift to log ground voltage indications when a ground exists, and to require the writing of a condition report if the ground exists for more than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. These procedure changes will ensure that a ground problem is closely monitored and that appropriate reviews and corrective action are accomplished.

Date When Full Com liance Will Be Achieved Full compliance was achieved on August 10, 1988, when Procedure OHP 4021.082.012 was revised to ensure that a ground problem is closely monitored and that appropriate reviews and corrective action are accomplished.

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