ML20086K227

Final Deficiency Rept Re Shielded Power Cable Bend Radius. Initially Reported on 820806.Conduits Being Reworked in Compliance W/Expected 840420 Completion Date.Cable 2KE-ECA5- 86-B Will Be Reworked & Grommet Installed by 840420

ML20086K227
Person / Time
Site:	Bellefonte
Issue date:	01/19/1984
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
NUDOCS 8401260359
Download: ML20086K227 (3)

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.v g TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 37401

, 400 Chestnut,S et Tower II BLRD-50-438/82-56

%4gh January 19, 1984 BLRD-50-439/82-50 U.S. Nuclear Regulatory Commission Region II Attn: Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30303

Dear Mr. O'Reilly:

BELLEFONTE NUCLEAR PLANT UNIT 1 - SHIELDED POWER CABLE BEND RADIUS DEFICIENCY - BLRD-50-438/82-56, BLRD-50-439/82 FINAL REPORT The subject deficiency was initially reported to NRC-0IE Inspector R. V. Celenjak on August 6,1982 in accordance with 10 CFR 50.55(e) as NCR 1889. This was followed by our interim reports dated September 7 and December 20, 1982. Since that time, related NCRs 2003, 2372, and 2490 have also been reported. Our final report for NCR 1889 was submitted on September 8,1983 Enclosed is our final report for NCRs 2003, 2372, and 2490.

If you have any questions concerning this matter, please get in touch with R. H. Shell at FTS 858-2688.

Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mills, Manager Nuclear Licensing Enclosure ',

cc: Mr. Richard C. DeYoung, Director (Enclosure)

Office of Inspection and Enforcement i U.S. Nuclear Regulatory Commission >

Washington, D.C. 20555 ,

Records Center (Enclosure) l Institute of Nuclear Power Operations l 1100 circle 75 Parkway, Suite 1500 l Atlanta, Georgia 30339 s

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8401260359 840119 C PDR ADOCK 05000438 +

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An Equal Opportunity Employer j I

• ENCLOSURE

.. t BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 SHIELDED POWER CABLE BEND RADIUS DEFICIENCY NCRs 2003, 2372, AND 2490 BLRD-50-438/82-56, BLRD-50-439/82-50 10 CFR 50.55(e)

FINAL REPORT Description of Deficiency NCR 2003 Minimum bend radii of cables were exceeded when routed in exposed conduit runs containing Crouse-Hinds form 7 condulets. Cables are installed in exposed conduits for safety-rezated and nonsafety-related systems throughout the entire plant. The cause of this deficiency is the failure by TVA to give proper consideration to bend radius requirements for electrical cable installation.

NCR 2372 During an inspection of cable bend radii in medium voltage switchgear, three cables were identified as exceeding cable bend requirements. The cause of this deficiency is the failure by TVA to give proper consideration to bend radius requirements for electrical cable installation. ,

NCR 2490 Low voltage power cables OVC-ECA4-130-A and OVC-ECA4-140-B which are to be terminated in Class 1E motor control center (MCC) equipment 1EI-EMCC-61-A and 1EI-EMCC-66-B cannot be terminated without violating their minimum bending radius. The cause of this deficiency is the failure by TVA to give proper consideration to bend radius requirements for electrical cable installation.

Safety Implications - All NCRs 6 Bending the subject power cables to a value more severe than specified would add stresses to the cables which could cause premature failure.

Failure of cables which provide control to safety-related equipment would, in turn, adversely affect the safety of operations of the plant.

Corrective Action NCR 2003 From information received from cable vendors along with a review of cable bending radius requirements in Insulated Cable Engineers Association (ICEA) standards, TVA's Division of Engineering Design (EN DES) approved Electrical Design Standard DS-E12.1.5 on September 20, 1983, which includes relaxed values for installing insulated cables. This design standard was

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distributed on Ssptember 20, 1983. DS-E12.1.5 d:ccribss the minimus i bending radii for pulling c blo during in;tallntion and for training cabla * .-

after pulling. This design standard supersedes section 3 0 of DS-E13.1.2 R0 and Table 3 2.1.2-1 of TVA Construction Specification G-38, revision 3 A specification revision notice, SRN-G-38-2 was issued on October 26, 1983, to revise G-38; Table 3 2.1.2-1 is deleted in this revision and DS-E12.1.5 is mferenced for minimum bending radius requirements.

Also, from examinat'ons of conduit bodies performed by Bellefonte site '

personnel, the minimum training radius of cables incide conduit bodies was established . This information was transmitted to EN DES for incorporation into Electrical Design Standard DS-E13.6.2 "Use of conduit Bodies in Conduit Systems" which was issued on November 15, 1983 A TVA Office of Engineering Design and Construction task force was formed July 1, 1983, to identify,' evaluate, and resolve cable bend radius problems at Watts Bar (WBN) and Bellefonte (BLN) Nuclear Plants. As part of the task team's effort, a computer program, utilizing vendor's condulet bend radius data, was run on conduits containing Class 1E cables in an effort to determine areas where bend radius problems might exist. From a walkdown of suspect conduits, only 24 contained condulets that have cables installed to less than the training values of Electrical Design Standard DS-E12.1.5; these are identified in Bellefonte Nuclear Project Quality Control Investigation Reports 36988, 36989. and 36990. TVA's Division of Construction (CONST) has connitted to reworking the 24 conduits to bring the cables installed therein into compliance with the minimum bending radii of DS-212.1.5 with an expected completion date of April 20, 1984. No drawing revisions are necessary as a result of this rework.

NCR 2372 The three cables under the scope of this NCR were supplied on Bellefonte transfer requisition 828828 and were originally furnished by Collyer Insulated Wire on Watts Bar Nuc'. ear Plant contract 77K5-822173-3.

Collyer's January 24, 1983, letter submitted cable test results (Report No.

83-3) for tests performed on a cable. sample (500 MCM, 8-KV, type EPSJ 1/C cable) furnished on the above contract. In testing a sample cable of smaller than normal bend radius, Collyer found no results to indicate a shorter cable life than if the cable had been trained at the normal bending radius. The Collyer also indicated that a bend radius of 8.0 times the O.D. of the cable or greater is acceptable. The cables listed in this NCR '

(2/0 AWG, 8 KV, type EPSJ, 1/C cables) are of the same construction as the test sample. Since the three cables have a smaller 0.D. than the test sample and are, therefore, more flexible, we have determined that their minimum bend radius is relaxed to 9.1 inches (based on 8.0 times the cable 0.D.).

t Based on the above test data compared to the installed cable bend radius, we have determined the following:

1. Cables 2KE-ECAS-60-A and 2KE-ECAS-73-B have an installed bending radius of 9.25 inches. Therefore, these cables are acceptable as installed.

1. 2. Cable 2KE-ECAS-86-B his an installed c bls bend radius of 5 3 inchno occuring whsre it entcrs switchgrar compartment 2EG-EMVS-12F-B from the wire gutter. From an enginee..ng evaluation of the cable design and the minimal amount of rework that is necessary at the stitchgear, the serviceability of the. reworked cable will not be adversely affected, provided the normal construction functional tests have been met following the rework. Therefore, this cable shall be reworked to obtain the minimum 9.1-inch or better bending radius, according to established procedures. .

Appropriate design drawing (s) have been revised to modify the cable raceway so this cable can be reworked under algineering change notice (ECN) 2386. Rework will be completed by April 20, 1984.

Cable bend radius values are specified in No. G-38. The values vary according to the type of insulation and the outside diameter of the cable.

NCRs have been written where the installed Class 1E cables do not meet the specified requirements, and they are being dispositioned on a case-by-case basis. In somes cases, relaxed cable bend radius values have been obtained from the cable manufacturers to allow acceptance of the as-installed configurations.

NCR 2490 ,

Since the identification of several cable bend radius deficiencies, TVA has relaxed its overly-conservative cable bend radius requirements. By relaxing these requirements, the cables under the scope of this nonconformance repdrt (NCR) can be properly resolved with the addition of a 2-inch hole being cut in the central divider of the MCC compartments. An appropriately sized grommet will be installed to protect the cable. This work will be completed by April 20, 1984.

Action to Prevent Recurrence - All NCRs To prevent recurrence in future installations, instructions have been included in Specification Revision Notice SRN-G-38-2, section 3.2.1.6 which direct CONST to verify that cables can be installed and terminated without violating the minimum bend radius criteria of Construction Specification G-38 before performing the work. Further, they have been directed to resolve all identified cab.le bend problems through coordination with the appropriate design organization.

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