ML19210B257

Deficiency Rept Re Discrepancies Between Physical Cable Count & Cable Tray Loading Summary Quantities.Seven of 20 Safeguard Cable Trays Randomly Selected Did Not Agree W/ Summary.Caused by Revised Pull Clips W/Routing Change

ML19210B257
Person / Time
Site:	Three Mile Island
Issue date:	12/12/1973
From:	Creitz W METROPOLITAN EDISON CO.
To:
Shared Package
ML19210B256	List: ML19210B257
References
NUDOCS 7911040211
Download: ML19210B257 (3)

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POST OFFICE BOX 542 READING, PENNSYLVANI A 19603 TELEPHONE 215 - 929 3501 December 12, 1973 Dr. D. F. Knuth, Director Directorate of Regulatory Operations Office of Reputation U. S. Atomic Energy Commission Washington, D. C. 20545 Daar Dr. Knuth:

Subject:

Three Mile Island Nuclear Station Unit #1 Docket No. 50-289 Physical Cable Count vs. Cable Tray Summary Quantities The AEC was notilied via telecon on November 12, 1973 of a situation which may be considered reportable under 10CFR 50.55 (e) (1) (iii),

" Conditions of Construction Permits". This relates to discrepancies noted by GPU personnel between physical cable count and the cable tray loading summary quantities.

DESCRIPTION OF INCIDENT An audit was performed by GPU personnel to verify the physical count of cables in safeguard cable trays utilizing the cable tray loading summary. Twenty safeguard cable trays were selected at random and physical cable counts were made at specific coordinates. The physical cable count was identical to the cable tray loading summary quantities for 13 safeguard cable trays. However, seven safeguard cable trays did not agree with the summary. A summary of the audit findings and the corrective action are shown in the attached table.

EVALUATION The discrepancy for audit findings #1, #2, and #3 (cable trays 834, 933 and 830) was caused by issuance of revised pull slips, having a routing change, after the non-safeguard cables had been pulled. Since the cables were pulled, field personnel filed the revised pull slip without repulling the cable. Therefore the cable tray loading summary indicated the latest pull slip routing while the installation was to the previous

.ull slip routing. An analysis indicated that the circuits *can remain

installed.

Accordingly, a check was made in the field of all pull slips which were revised for a routing change. It was found that 258 circuits out of approximately 17,500 circuits were in this category. Of the 258 cir-cuits, a total of 91 circuits have been verified a gje0h& Sit 3eroutins 1585 i17 2//

Dr. D. F. Knuth, Director December 12, 1973 design criteria with the present installation. The remaining 167 circuits are still being investigated.

Audit finding #4 (cable tray 142) is still under investigation to resolve the differences between the physical count of non-safeguard cables and the tray loading summary. A physical count of all safe-guard circuits in this cable tray confirms that this count corresponds with the safeguard circuits in the tray loading summary quantity.

A recount of cable tray 136 (audit finding #5) confirmed that the physical cable count corresponded with the tray loading summary quantity. Two circuits were tied against the side of the tray and were not counted during the original audit.

Audit finding #6 (cable tray 167) investigation indicated one non-safeguard circuit (RB-146) was routed into the wrong underground duct. However, this did not affect the physical count of tray 167.

Further investigation revealed that the dropout of a non-safeguard circuit (CBE-1006) was not located as identified on the conduit drawing. Therefore, the circuit was not included in the physical cable count for this tray. An engineering design request is being issued to update pull slips.

Audit finding 7 (cable tray 166) investigation revealed that the cok-puter routing program identified 48 circuits to exit at a dummy point while in fact the circuits dropped out at various points (near the dummy point). When these circuits were taken into account, the physical cable count corresponded to the tray loading summary.

Audit finding #8 (cable tray 830) investigation indicated that this cable tray loading had not been updated for percent fill. The per-cent fill was updated from 5.2% to 22%.

ANALYSIS OF THE SAFETY IMPLICATIONS All engineered safeguard circuits investigated to date have met the routing design criteria and the Safety Analysis Report commitments.

CORRECTIVE ACTION To minimize the recurrence of revised pull slips not being returned because the circuits have already been pulled, existing procedures are being reemphasized to both design and field personnel.

The investigation is continuing in order to resolve the aforementioned outstanding items. When it is completed, a final report will be sub-mitted to you.

Sincerely,,/ 1585 118 0/?7&r~

W. M. CREITZ President WMC:cq

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