ML20004B413

Final Deficiency Rept,Originally Reported on 800313,re Cable Damaged During Cable Pulling.Caused by Polypropylene Rope Used in Installation Process.Damaged Cable Replaced. Info Bulletin Modifying Installation Practices Released

ML20004B413
Person / Time
Site:	Grand Gulf
Issue date:	05/19/1981
From:	Mcgaughy J MISSISSIPPI POWER & LIGHT CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
10CFR-050.55E, 10CFR-50.55E, AECM-81-172, NUDOCS 8105280202
Download: ML20004B413 (4)

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A MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi E m e nag P. O. B O X 16 4 0. J A C K S O N, MIS SIS SlP PI 3 9 2 0 5 JAMES P. McGAUGHY, JR.

AsalSTANT VICE PRf 5sOEnf May 19, 1981 i Office of Inspection & Enforcement U. S. Nuclear Regulatory Commission I l

Region 11 '

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l 101 Marietta Street, N.W. c .. ,

Suite 3100 (, '"SE 2 7 I381 h Q l Atlanta, Georgia 30303 "A g -

Attention: Mr. J. P. O'Reilly, Director /

SUBJECT:

Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 5 16/417 File 0260/155 /15526 l PRD-80/05, Fi 1 Report, Cable Damage During Rope Pulling AECM-81/172 On March 13, 1980, Mississippi Power & Light Company notified Mr. F.

I Cantrell, of your office, of a Potentially Reportable Deficiency (PRD) at the l Grand Gulf Nuclear Station (GGNS) construction site. The deficiency concerns l rope burn damage to cables in conduit. This deficiency was previously determined reportable under 10CFR50.55(e) in our letter to you dated February 20, 1981. This deficiency is not reportable under 10CFR21 as these cables had not been turned over to MP&L.

l l During investigation into this deficiency, it, was noted that the insulation and/or jacket on some of the cables had been nicked or cut, etc.

apparently during installation. This dar.sge appeared to be minor, but will be investigated to determine if it could adversely affect the performance of the cables or the safe operation of the,auclear power plant over its lifetime.

The decision was made to confine PRD-80/03 only to the damage caused by rope burns and to initiate another investigation into other types of construction damage. This deficiency will be addressed as 'RD-81/25. This letter will serve to notify you of this PRD. We expect to complete our final report on PRD-81/25, Construction Damage to Cables, by November 15, 1981.

Attached is our final report on PRD-80/05, Cable Damage During Rope 3 Pulling.

Yours truly, / /

I J. P. McGaughy, Jr.

M R280gch Member Middie South utilities System S

1. AECM-81/172 Mr. J. P. O'Reilly NRC Page 2 KDS:st 1 Attachment ec: Mr. N. L. Stampley Mr. R. B. McGehee Mr. T. B. Conner-Mr. Victor Stello, Director Office of Inspection & Enforcement i U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. G. B. Taylor South Miss. Electric Power Association P. O. Box 1589 Hattiesburg, MS 39401 i

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Attachment to AECM-Il/172 Page 1 of 2 FINAL REPORT FOR PRD-80/05 I. Description of the Deficiency Cable damage was sustained during the cable pulling process. Two constructor Nonconformance Reports (NCRs) have documented this condition in three noted cases of cable damage. In both cases, the damaged cables are associated with Z51, the Control Room HVAC System. The condition originally was noted when all cables were removed from two conduits to allow the pulling of an additional cable into that conduit. The initial findings have indicated that the cables were damaged by the polypropylene pulling rope. The nature of damage rangas from jacket chafing to insulation cut through to the conductor.

This deficiency is applicable only to Unit 1. The deficiency does not apply to the NSSS supplier.

To determine the extent of the damage, our constructor undertook an extensive and comprehensive testing program. The total number of safety related conduits was reviewed. Conduits with a very small probability of installation damage to the cables were not included in the evaluation.

A total of 277 conduits susceptible to rope burn damage to the cables were analyzed. Forty seven (47) of these conduits had the cables removed and visually inspected. Four (4) of these cables were found to have rope burn damage. ,

The physical parameters of the remaining 230 conduits were analyzed as to potential for installation damage to the cables. Twenty (20) " worst case" conduits were selected. These conduits were filled with Poly Water and the cables were High Potential tested. Of a total of 141 cables in these conduits, eleven (11) failed the High Potential test.

Three (3) of the cables failed the test because of rope burn damage.

The other test failures were 'ue d to other causes.

A cucond group of twenty (20)' " worst case" conduits was then selected.

l The same testing procedure that was performed on the first group was then performed on this group. No cables failed the High Potential test "oecause of rop ' burn damage. Since all remaining cenduits have physical configurations which have less potential for damage than the tested conduits, our constructor assumed that all damaged cables had been l located and that no further testing was necessary.

A total of ten (10) cables with rope burn damage were identified. These t

cables apply to numerous systems. At least eight (8) other cables l

failed the High Potential test because of known construction damage or l ,

because of unknown causes.

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Attachment to AECM-81/172 Page 2 of 2 The cause of the deficiency was the cable installation process which used a pe17 propylene pull rope to pull in "new" cables over existing cables alre ady in a conduit.

II. Analysis of Safety Implications Because of tha generic implications of the deficiency, and because of its applicability to numerous systems, it has been determined that this condition, had it gone undetected, could have adversely affected the safety of operations over the lifetime of the plant, and as such, is reportable under 10CFR50.55(e).

The cables had not been turned over to MP&L for acceptance, so this condition is not reportable under 10CFR21.

III. Corrective Actions Taken All identified cables damaged due to rope burn have been replaced.

To preclude recurrence of this deficiency, the Project Field Engineer

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issued an Information Bulletin modifying cable installation practices.

A training session was conducted for responsible Field Engineers to identify the problem and to provide instructions for the modified pulling practices. This bulletin precludes the use of polypropylene pulling rope.

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