ML20076K745
| ML20076K745 | |
| Person / Time | |
|---|---|
| Site: | Bellefonte  |
| Issue date: | 09/08/1983 |
| From: | Mills L TENNESSEE VALLEY AUTHORITY |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NCR-1889, NCR-2003, NUDOCS 8309150253 | |
| Download: ML20076K745 (3) | |
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TENNESSEE VALLEY AUT140RITY, _
CHATTANOOGA. TENNESSEE 37 f
~.
- 400 Chestnut Street Tower II
'
- GIA BLRD-50-438/82-56 BLRD-50-439/82-50 U.S. Nuclear Regulatory Conunission Region II Attn:
Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Oeorgia 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 THIRD INTERIM REPORT The subject deficiency was initially reported to NRC-0IE Inspector R. V. Crlenjak 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 NCR 2003 has also been reported. Enclosed is our third interim report for NCR 2003 and our final report for NCR 1889. We expect to submit our next report on NCR 2003 by January 20, 1984. The deficiency has also been reported on our Watts Bar Nuclear Plant as NCR 4194R.
Please note that TVA does not now consider NCR 1889 a nonconforming condition adverse to the safe operation of the plant. Therefore, we will amend our records to delete the subject nonconformance as a 10 CFR 50.55(e) item.
If you have any questions concerning this matter, please get in touch with R. H. Shell at FTS 858-2688.
Very truly yours, l
TENNESSEE VALLEY AUTHORITY l
D$ W
)ht.L.M. Mills, Manager Nuclear Licensing l
Enclosure cc:
Mr. Richard C. DeYoung, Director (Enclosure)
Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Records Center (Enclosure)
Institute of Nuclear Power Operations 1100 Circle 75 Parkway, Suite 1500 Atlanta, Georgia 30339 8309150253 830908 EFiCIAI' COPY PDR ADOCK 05000438 ff 1983-TVA SOTH ANNIVERSARY l\\
An Equal Opportunity Employer
ENCLOSURE BELLEFONTE NUCLEAR PLANT UNITS 1 AND 2 SHIELDED POWER CABLE BEND RADIUS DEFICIENCY NCRs 1889 AND 2003 BLRD-50-438/82-56, BLRD-50-439/82-50 10 CFR 50.55(e)
THIRD INTERIM REPORT NCR 1889 Description of Deficiency Some cable tray fittings used at Bellefonte allow bending radii of 8-kV shielded power cables to be less than the minimum required by TVA construction specifications. These specifications require a minimum bending radius of 12 times the cable outside diameter (OD) while the 12-inch radius tray fittings allow the cables to be bent from about 7.4 to 10.7 times cable OD depending on cable size. The design of the plant cable tray system was based on numerous factors; but in some cases, the bending radius required for the largest shielded power cables was not adequately c onsidered. These cables can be used in class 1E systems and the added stress of the tighter bends conceivably could cause premature failure.
Safety Implications The Okonite Company, Collyer Insulated Wire, and Triangle-PWC, Incorporated, furnished medium voltage (8kV and/or 15kV) power cable to Bellefonte. Okonite has furnished thu majority of this cable on contracts 81K5-828088, 79K5-825903, and 79K7-825580. Their letters to TVA dated May 12 and June 7,1983, state that the concern in the minimum installed radius is that the cable shield system does not buckle or separate at the tape overlap. They also state that their shield tape over'ap is 12-1/2 percent minimum, and their calculations show that the 12-inch bend radius will not cause tape separation and, therefore, will not be detrimental to their 8kV medium voltage power cables.
Collyer's 8kV medium voltage power cable manufactured on contract 77KS-822173-3 was transferred to Bellefonte from Watts Bar Nuclear Plant on transfer requisition 828828. Collyer's letter to TVA dated January 24, 1983, with ineir test report No. 83-3, also showed that a bend radius of 12 inches 41.
not be detrimental to their cable.
15kV power cat'.e :
n-used in any Class 1E safety-related circuits at Bellefonte.
Lowe,-
using the same bend criteria as discussed above for 8kV poser cable likewise shows that the 12-inch radius bends will not adversely affect the ability of the 15kV cable furnished by Okonite to provide service over its expected life.
Triangle-PWC furnished 8kV and 15kV power cable on contract 75K7-86150-2. However, this cable has been removed from cable trays in Category I structures, and its further us6 ?rohibited as a corrective action for NCR BLN EEB 8004, which dealt with flame retardancy.
s Therefora, we have datermined that the installation of tha Okonite and Collyce cable in cable tray fittings (such as elbows, tees, and crosses) with 12-inch radii will not adversely affect service ability of the cable and is acceptable for use "as is." No further corrective action is required.
A review was made of design requirements at other TVA nuclear plants, and NCR 4194R was written for a similar condition at Watts Bar. No other violation of TVA bend criteria due to standard cable tray fittings was found at other nuclear plants.
To identify, evaluate and resolve Class 1R cable bend radius problems at Watts Bar and Bellefonte Nuclear Plants, TVA has appointed a task team of representatives from the Divisions of Engineering Design (EN DES) and Construction (CONST). Several problems have been identified at both plants, and NCRs have been written where the installed Class 1E cables do not meet the requirements of TVA Construction Specification G-38.
These p
NCRs are being dispositioned on a case-by-case basis. In some cases, relaxed cable bend radius values have been obtained from the cable manufacturers to allow acceptance of the as-installed configurations. For all future installations, TVA will comply with the established cable bend radius values; or, receive specific relaxation of these values from vendors before cable installation.
Therefore, there are no safety implications to Bellefonte, and TVA no longer consider this NCR to be reportable under the requirements of 10 CFR 50.55(e).
NCR 2003 Description of Deficiency 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-related and nonsafety-related systems throughout the' entire plant.
Interim Progress TVA's Division of Construction (CONST) was requested by the Division of Engineering Design (EN DES) to reevaluate NCR 2003 on the basis of condulet bend radii obtained from the Crouse-Hinds Company. Using the vendor's data, CONST has developed a procedure for doing this reevaluation and will forward the results to EN DES for resolution of the nonconformance.
_ _____.