ML19276E061
| ML19276E061 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 02/27/1979 |
| From: | Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 024C, 24C, NUDOCS 7903020263 | |
| Download: ML19276E061 (2) | |
Text
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VlHGINI A ELECTRIC AND POWCM COMP ANY. RICHMOND, VIRGINI A 23261 February 27, 1979 Mr. James P. O'Reilly, Director Serial No. 024C Office of Inspection 8' Enforcement PSE&C/LCK:adw:me U. S. Nuclear Regulatory Comission Region II
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Docket No. 50-339 101 Marietta Street, Suite 3100 Atlanta, Georgia '30303
Dear Mr. O'Reilly:
In accordance with 10CFR50.55(e), the NRC, Region II, was notified on January 8, 1979 that the North Anna Unit 2 Axial Power Distribution Monitor-ing System (APDMS) provided by Westinghouse. Electric Corporation does not account for the in-core moveable detector background signal when determining the ar.ial flux shape, Fj(z).
In our previous letter of February 16, 1979, Serial No. 024B we pre-sented our final report on this concern stating that the deficiency would-be corr;cted by implementing administrative procedures requiring the reactor operator'on North Anna Unit 2 to review the flux traces used by the APDMS in order to: characterize' detector background levels and flux amplitude. Also, the APDMS input values would be adjusted in order to conservatively account -
for the effects -of detector background. He explained that'these procedures were currently being followed at North Anna Unit 1.
Following the transmittal of this letter, your Mr. M. S.. Kidd requested this supplemental letter con-cerning the APDMS matter..
It is Vepco's opinion that the proposed administrative procedures in our
. letter of February 16, 1979 satisfactorily resolve all potential safety im-
.p11 cations and as such, the deficiency caused by the APDMS hardware's in-
. ability to account for detector background levels is corrected. However, the
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operations staff at our North Anna pwer station is currently considering the possibility of. alternate methods of lessening the amount of reactor operator intervention necessary to the correct operation of APDMS. The primary method now being considered consists of possible 'APDMS hardware / software modifica-tions.
In any case, the fact remains that all possible safety implications associated with this APDMS problem have been adequately corrected and thus no longer pose a concern,
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N' Mr. James P. O'Reilly 2
4 This letter is to be considered an addition to our final report on this item and no further correspondence is anticipated.
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Very trul
- ours, Sam C. B
, Jr.
Senior Vice President Power Station Engineering and Construction
. cc: Mr. ~ John G. Davis Acting Director Office. of; Inspection & Enforcement Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation
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