B18582, Additional Information Regarding Thermo-Lag, Related Ampacity Derating Issues

Additional Information Regarding Thermo-Lag, Related Ampacity Derating Issues

ML020700482
Person / Time
Site:	Millstone
Issue date:	02/22/2002
From:	Price J Dominion Nuclear Connecticut
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
B18582, GL-92-008, TAC M82809, TAC MA3392
Download: ML020700482 (2)

Text

Dominion Nuclear Connecticut, Inc.

Dominion Millstone Power Station Rope Ferry Road Waterford, CT 06385 FEB 2 2 2002 Docket No. 50-336 B18582 RE: GL 92-08 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Millstone Nuclear Power Station, Unit No. 2 Additional Information Regarding Thermo-Lag Related Ampacity Derating Issues In a letter dated February 17, 1999,(1) Northeast Nuclear Energy Company provided an updated response to a Nuclear Regulatory Commission (NRC) Staff request for additional information (RAI) concerning Thermo-Lag related Ampacity Derating issues.(2)

The original response to the RAI was provided on July 11, 1997.(3)

In a recent conference call, the NRC Staff identified certain issues related to the methodology used in determining the adequacy of the cables in raceway Z23HA10

(

Reference:

Millstone Unit No. 2 calculation 96-ENG-10528E2, Rev. 1, "Ampacity Derating due to Thermo-Lag)." The specific issues related to raceway Z23HA10 are as follows:

1) The n' factor is misinterpreted from Neher-McGrath paper equation No. (41).

Value of n' should be 6 in lieu of 3.

2) The analysis for determining temperature drop for cable surface to conductor appears to be incorrect or incomplete. The temperature from cable surface to conductor is not calculated.

3) The model is used for 1/conductor cable instead of 3/C for triplex cable.

(1) R. P. Necci letter to U.S. Nuclear Regulatory Commission, "Millstone Nuclear Power Station, Unit No. 2, Updated Response to Request for Additional Information Regarding Thermo-Lag Related Ampacity Derating Issues (TAC NO.

MA3392),"

dated February 17, 1999.

(2)

P. F. McKee letter to Neil S. Carns, "Request for Additional Information Regarding Thermo Lag Ampacity Derating Issues (TAC NO. M82809)," dated May 13, 1997.

(3) Neil S. Cams letter to U.S. Nuclear Regulatory Commission, "Millstone Nuclear Power Station, Unit No. 2 - Reponse to Request for Additional Information Regarding Thermo-Lag Related Ampacity Derating Issues (TAC NO. M82809)," dated July 11, 1997.

U.S. Nuclear Regulatory Commission B18582/Page 2 The purpose of this letter is to acknowledge the issues and to inform the NRC that the issues have been entered in our Corrective Action Program.

Specifically, Dominion Nuclear Connecticut, Inc., has written a Condition Report (CR-02-00125) to capture the issues and determine further corrective action. It is noted that there are no operability or reportability concerns associated with the issues.

There are no regulatory commitments contained within this letter.

If you should have any questions on (860) 440-2080.

the above, please contact Mr. Ravi Joshi at Very truly yours, DOMINION NUCLEAR CONNECTICUT, INC.

'resident - Millstone Sworn to and subscribed before me this QQ10day of.

2002 NotakY.PPublic My Commission expires o*'o*6LD cc:

H. J. Miller, Region I Administrator J. T. Harrison, NRC Project Manager, Millstone Unit No. 2 NRC Senior Resident Inspector, Millstone Unit No. 2 Lorrie A. Arzamarski Notary Public Commission Expires February 28, 2006