ML20247L221
| ML20247L221 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 09/14/1989 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 89-646, NUDOCS 8909220158 | |
| Download: ML20247L221 (2) | |
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VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 Septanber 14, 1989 U.S. Nuclear Regulatory Commission Serial No.:
89-646 Attention: Document Control Desk NL/JBL Washington, D.C. 20555 Docket Nos.: 50-338 50-339 License Nos.: NPF-4 NPF-7 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 IHot TEMPERATURE REDUCTION PROGRAM AND TECHNICAL SPECIFICATION REPORTING REQUIREMENTS FOR THE CORE SURVEILLANCE REPORT Virginia Electric and Power Company is pursuing implementation of a Reactor Coolant System T ot temperature reduction for both North Anna Units 1 and 2.
T ot H
H temperature reduction is a key part of our program to extend the life of the North Anna steam generators. The reduced hot leg temperature reduces the potential for initiation and propagation of primary water stress corrosion cracking (PWSCC) of the steam generator tubes. We currently plan to implement the T ot temperature reduction H
program for North Anna Unit 1 by November 17,1989, and Unit 2 by November 3, 1989.
Implementation of the T ot emperature reduction program requires that nuclear core H t design calculations be modified. Specifically, the Relaxed Power Distribution Control calculations must be revised to support reduced teniperature operation for the remainder of the current North Anna operating cycles. These analyses will result in revised N(z) functions for normal operation of both Un'its.
North Anna Unit 1 began its eighth cycle of operation on July 16,1989 with the N(z) function for normal operation as described in the Core Surveillance Report submitted by lettcr April 28,1989. Likewise, North Anna Unit 2 began its seventh cycle of i
operation on May 9,1989 with the N(z) function for normal operation as described in Revision 1 of the Core Surveillance Report submitted dated May 22,1989. As stated above, the N(z) function for normal operation will change as a result of this temperature reduction program. Therefore, the Core Surveillance Reports for North Anna Units 1 and 2 mus.t be revised to reflect these new operating limits.
Technical Specification 6.9.1.7 requires that changes to the N(z) function for normal o,neration, as provided in the Core Surveillance Report, be submitted to the NRC sixty day prior to this inf.;rmation becoming effective.
However, the Technical e909220158 89o914 ADOI PDR ADOcK 05000338 FDL g
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e Specification provides for an alternate submittal date with NRC written approval.
Because of our commitment to maintaining steam generator tube integrity and associated concerns of PWSCC, we are interested in taking advantage of the THot temperature reduction program as soon as possible. Therefore, in accordance with this Teclinical Specification provision, we request the sixty day advance submittal requirement of Technical Specification 6.9.1.7 be waived by the NRC, and alternately, we propose to submit the revised Core Surveillance Reports by October 20,1989.
Based on our preliminary assessment of these required calculational changes, no core alterations nor physical changes to plant systems are expected. The preliminary assessment also indicates that no Technical Specifications changes will be required.
Should you have any questions, please contact us at your earliest convenience.
Very truly yours, 5 ob W. L. Stewart Senior Vice President - Power cc:
U. S. Nuclear Regulatory Commission 101 Marietta Street, N.W.
Suite 2900 Atlanta, GA 30323 Mr. J. L. Caldwell NRC Senior Resident inspector North Anna Power Station h