ML20011A003

Final Deficiency Rept Re Potential Loss of Solid Metallic Grounding of Flexible Conduit,Originally Reported on 801210. Ground Wires Will Be Installed from Flexible Conduits to Ground Bus.Also Reportable Under Part 21

ML20011A003
Person / Time
Site:	Grand Gulf
Issue date:	09/29/1981
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
REF-PT21-80 10CFR-050.55E, 10CFR-50-55E, 10CFR-50.55E, AECM-81-371, NUDOCS 8110060346
Download: ML20011A003 (6)

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• " ' " ' *C I MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi P. O. B O X 1640. J A C K S O N, MIS SIS SIP PI 3 9 2 0 5 "E[cEd'd"

• September 29, 1981 Gffice of Inspection & Enforcement s' y\e' (1 g U. S. Nuclear Regulatory Commission f If[ ,j-Region II '

101 Marietta Street, N.W. I' gOI '7

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Suite 3100 Atlanta, Georgia 30303

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\% N Attention: Mr. J. P. O'Reilly, Director -

~[jx ,,W, >f ..y \ j Dear Mr. O'Reillyi

SUBJECT:

Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 50-416/417 File 0260/15525/15526 PRD-80/70 Final Report Flexible Conduit Grounding AECM-81/371

References:

1) AECM-81/27, 1/9/81

2) AECM-81/112, 3/19/81

3) AECM-81/302, 8/31/81 On December 10, 1980, Mississippi Power & Light Company notified Mr. P.

K. Van Doorn, of your office, of a Potentially Reportable Deficiency (PRD) at the Grand Gulf Nuclear Station (GGNS) construction site. The deficiency con-cerns the potential loss of solid metallic grounding of the flexible conduit used by our NSSS supplier in the Power Generation Control Complex (PGCC) equipment.

We have determined that this deficiency, had it remained uncorrected, would be a substantial safety hazard and is reportable under the provisions of 10CFR50.55(e) and 10CFR21.

Attached is our final reput giving specific details.

Yours truly bf y J. P. McGaughy, Jr.

KDS:dr ATTACHMENT I Elk cc: See page 2 /

8110060346 810929 PDR ADOCK 05000 S

Mr. J. P. O'Reilly MCM-81/371 NRC Page 2 1

cc: Mr. N. L. Staapley

Mr. R. B. McGehee i Mr. T. B. ' Conner Mr. Victor Stallo, Director Office of Inspection & Enforcement

U. S. Nuclear Regulatory Commission -

Washington, D.C. 20555 Mr.. G. B. Taylor South Miss. Electric Power Association P. O. Box 1589 Hatt.iesburg, MS 39401

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bec: Mr. D. C. Lucken' Mr. J. Leatherman ,

Dr. D. C. Gibbs Manager of BWR-6 Licensir.g Mr. J. N. Ward General Electric Company Mr. J. P. McGaughy, Jr. 175 Curtner Avenue Mr. J. D. Heaton San Jose, Ca. 95125 ,

Mr. R. S. Trickovic Mr. J. W. Yelverton

Mr. L. F. Dale Mr. D. M. Houston Mr. C. K. McCoy U. S. Nuclear Regulatory Commission Mr. T. H. Cloninger Division of Licensing Mr. R. A. Ambrosino Washington, D. C. 20555 i Mr. R. C. Fron Mr. G. B. Rogers Mr. S. H. Hobbs Mr. J. Matore Mr. L. E. Ruhland U. S. Nuclear Regulatory Commission Mr. D. L. Hunt Division of Licensing Mr. A. G. Wagner Washington, D. C. 20555 Mr. P. A. Taylor PRD File .

File. Mr. Bruce J. Cochran Cochran Consulting Company P.O. Box 270503 Tampa, Florida 33688

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. Att:chment to AECM-81/371 Pega 1 cf 3 r

FINAL REPORT FOR PRD-80/70 Reportable Under 10CFR50.55(e) and 10CFR Part 21

1. Name and address of the individual...infor0?ng the commission:

T. E. Reaves, Jr.

Manager of Quality Assurance ,

P.O. Box 1640 Jackson, Mississippi 39205 Notification of Part 21 applicability made to Mr. J. P. O'Reilly, NRC, Region II by letter AECM-81/371, September 29, 1981. The deficiency was also reported to the NRC under 10CFR21 by General Electric in their letter dated December 8,1980.

2. Identification of the facility...which...contains a defect:

Grand Gulf Nuclear Station (GGNS) Units 1 and 2 Port Gibson, Mississippi 39150

3. Identification of the fire... supplying the basic component which ... con-tains a defect:

Supplied to Grand Gulf by the Genecel Electric Company, San Jose, California.

4. Nature of the defect...and the safety hazard which...could be created by such defect...:

A. Description of the Deficiency The flexible conduit contained in Power Generation Control Complex (PGCC) equipment, designed and supplied by General Electric, has a potential loss,of solid metallic grounding at the termination cab-inet and/or the panel.

In the termination cabinet installations, the conduit la firmly attached with a locking ring to a termination module, which is an acceptable gropnd connection. However, the termination module is ultimately mounted on a painted (high electrical resistance) sur-face. No procedure had been issued by the manufseturer, to insure that the paint was removed from the panel surfaces before termina-tion modules were meunted, or to check that the termination module

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made a low-resistance connection to the panel steel.

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Attachment to AECM-81/371

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B. Analysis of Safety Implications In the NSSS this could affect the Reactor Protection System, the Nuclear Steam Supply Shutoff System and the Neutron Monitoring System. This applies to both Unit I and Unit 2.

One of the purposes of the flexible conduit is to provide a low resistance path to gruond under certain short-circuit conditions.

This insures that upsi. ream fuses will melt and thereby prevent " hot shorts" which have the potential for preventing the completion of a protective function (de-energizing various circuits). There is the potential of loss of solid metallic grounding of the flexible con- ' '

duit either at the termination cabinet or at the panel. This has the potential for preventing operation of fail-safe logic associated with the Reactor Protection System.

5. The date on which the information of such defect....was obtained.

Mississippi Power and Light received informat'. ;n of the defect oC December 31, 1980. We reported the deficiency to Mr. P. K. Van Doorn of your office an a Potestially Reportable Deficiency on that date. Since that date MP&L has filed three (3) interim reports to inform the Commis-sion of the progresa and status of the resolution of this deficiency. An evaluation for Part 21 has been completed and the MP&L " Responsible Officer," Mr. J. P. McGa2ghy, Jr., has been notified.

6. In the case of the basic component...the number and location of all such components.

The termination modules that have the potential for improper grounding are installed in the Power Generation Control Complex at the GGNS site.

We do not have knowledge of the location of defective equipment located other than at GCMS. -

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7. Tne corrective action which has been taken....the name of the individual

... responsible for the action; and the length of time that has been ...

taken to complete the action.

(a) Corrective Actions Taken

, General Electric has issued FDI-WATP for Unit 1 and FDI WBNY for Unit 2. Ground wires will be installed from the flexible conduits to a ground bus. This will ensure a low resistance path to ground.

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. 5 Attachment to AECM-81/371 s' Peg 2 3 cf 3 (b) Responsible Individual G. B. Rogers, Jr.

Site Manager Mississippi Power and Light Company.

(c) Length of Time to Complete Actions The problem war identified on Dec u ber 31, 1980. General Electric issued Field Disposition Instructions WATP for Unit 1 and WBNY for

, Unit 2 on June 25, 1981 for the work. to be performed at the GGNS site. Unit L work is scheduled to be completed by October 21, 1981. Rework on Unit 2 will be complete before fuel load of the tanit.

8. Any advice related to the dnfact....that has been, is beir.g, or will be given to purchasers or licensees:

As the deficiency did not originate with MP&L, we have no advice to offer.

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