ML20236J668

Responds to NRC Re Violations Noted in Insp Rept 50-412/87-32.Author Concludes That Circumstances Cited in Notice of Violation Do Not Represent Violation of NRC Regulations & Requests Violation Be Withdrawn

ML20236J668
Person / Time
Site:	Beaver Valley
Issue date:	07/24/1987
From:	Sieber J DUQUESNE LIGHT CO.
To:	Johnston W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
2NRC-7-178, NUDOCS 8708060240
Download: ML20236J668 (4)

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2NRC-7-178 July 24, 1987 7V4 DucluesneLight 0,esver Valley No. 2 Unit Project Organization h

Ext.160 Telecopy 4 S.E.G. Building P.O. Box 328 Shippingport, PA 15077 United States Nuclear Regulatory Commission Region I 631 Park Avenue.

. King of Prussia,'PA 19406 ATTN:

Mr. William V-'Johnston, Acting Director Division of Reactor Safety SbBJECT:

Beaver Valley Power Station Unit No. 2 Docket No. 50-412-Inspection Report 50-412/87-32

REFERENCE:

1) Letter dated June 18, 1987. W. V. Johnston' to J. J. Carey Gent'emen:

The above referenced letter transmitted a Notice of Violation as Appendix A. of this letter provides Duquesne Light Company's (DLC) respo :se pursuant to the requirements of 10CFR2.201 and the NRC's Notice of Viol ation.

Based on our review we believe that the circumstances cited in the Notice of Violation do not represent a violation of NRC regulations. The bases for our opinion is included in the response.

DUQUESNE LIGHT COMPANY By hd M,

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J. D. Sieber ce President Nuclear DLC/ijr NR/DLC/IR/8732 Attachment AR/NAR cc: Mr. P. Tam, Project Manager (w/a)

Mr. J. Beall, NRC Sr. Resident inspector (w/a)

Mr. L. Prividy. NRC Resident Inspector (w/c)

INP0 Records Center (w/a)

NRC Document Control Desk (w/a) 870B060240 870724 DR ADOCK 05000412

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Uniter!tStates Nuclear Regulatory Commission Mr. William V. Johnson, Acting Directdr Inspection Report 50-412/87-32 Page 2 q

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J. J. Carey w/ attachments I

w/ attachments C. E. Ewing w/ attachments I

G J. A. Hultz w/ attachments L. R. Knapp t

-- w/ attachments R. J. Druga i

w/ attachments K. D. Grer-w/ attachments

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T. P. No'aan w/ attace. ment s M. J. O'Neill w/attac hments S. C. Fenner w/ attachments

.V C. Richardson (S&W)(5) w/ attachments J. Sutton (S&W) w/ attachments A. A. Dasenbrock, SWEC w/ attachments R. Anstey, SWEC w/ attachments R. Wittschen, SWEC w/ attachments J. M. Grigsby (W) w/ attachments C. Majumdar BV-2-NCD-SEG/ Phase II PUC Audit - w/ attachments l

Distribution PDR-378 (4) w/ attachments Inspection 87-32 File w/ att achments NCD File s

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ATTACHMENT Violation 87-32-03 l

10CFR50, Appendix B, Criterion III requires that measures shall be established to assure that design basis for systems and components to which thi!. appendix applies are correctly translated into drawings, procedures and instructions.

The Beaver Valley Power cable specification 2BVS-828 to the Okonite Company and 2BVS-309 to the Kerite Company states in the Insulation Section, paragraph 2, that the cable thermal properties shall be such as to maintain its critical electrical and physical qualities during the 40 year plant life expectancy when the conductor temperature for normal operation will be 90*C.

This requires measures to be established to prevent the conductor temperature from exceeding the 90*C design limit.

Contrary to the above, on April 15, 1987 inspection procedure for protective wrap IP 12.1 dated March 30,1987 and installation drawings SECO 1.?.3.4-A40 Rev. 11, A-50 Rev. 9, A-52 Rev. 2, did not specify a limit for the maximum

~ number cf layers of the WT65 siltemp material on extended cable wraps to limit the power cable conductor temperature to 90*C during normal operating condi-tions.

This is supported by the Analysis J012241 which indicates that contin-uously operated loads serviced by number 6 triplex power cables wrapped with more than 2 layers of siltemp tape, can increase the coi.ductor temperature beyond 90*C.

This is a Severity Level IV violation.

(SupplementII)

Response

The referenced data furnished to the NRC during inspection 87-32 was based on maximum ampacity assumptions and were not representative of the actual condi-tions at BVPS Unit 2.

All of the temperature curves presented to the reviewer at the May 8th meeting were generated with the assumption that the cable carried the maximum permitted ampacity in the L-tray sections.

For a #6AWG triplex, copper cable, this ampa-city is 73 amps.

Beaver Valley Power Station Unit No. 2 (BVPS-2) cable sizing philosophy (2BVM-42) requires that the cables be sized for 125% of its actual full load current (FLA). A detailed review has been made of all safety related j

1. 6AWG, triplex cable which are siltemp wrapped to determine maximum actual FLA.

This review has shown a maximum actual FLA of 51 amps.

Therefore,1.25 X 51 amps = 64 amps vs. the previously assumed 73 amps.

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Based on the aspect of margin discussed, the most fully loaded #6AWG cable, when carrying its design 125% FLA will not exceed 67*C in the tray section.

If this cable were ' wrapped in the transition section with 3 layers of siltemp i

WT-65 (nominal thickness) for an infinitely long distance, its maximum conduc-tor temperature would not exceed 78'C per ICEA standard S-68-516.

This temper-ature will not degrade the long term performance of +he cable insulation.

The triplex #6AWG cable was selected as being representative of the worst case cable based on test data of temperature versus time plots.

Below is a tabula-tion of durations and maximum jacket temperatures for each cable.

This infor-mation was previously sent to the NRC via 2NRC-5-081 dated June 4,1985.

Heat Rise Duration Max Temp Test Cable LRA (min.)

Jacket of Fault Cable 1

500 MCM 1780 16.8 300*F 2

350 MCM 1579 13.5 360*F 3

4/0 1184 9.5 400*F 4

1. 2 501 8.3 406*F 5

1. 6AWG 315 8.3 850*F Based on these tests, the triplex #6AWG cable had the highest jacket temper-ature, and was selected as being representative of the worst case cable for BVPS-2.

Additional information has been provided via letter 2NRC-7-126 dated May 18, 1987.

In summary, the possibility that the conductor temperature could exceed 90*C appears to be based on the maximum permitted anpacity rather than the actual full load current.

Based on actual full load current, the maximum conductor temperature will not exceed 78'C.

For these reasors, our review of the Viola-tion cited leads us to the conclusion that the circumstances associated with this issue do not represent a Violation.

We t%erefore respectfully request i

that this Notice of Violation be withdrawn.

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