ML19263B951
| ML19263B951 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 01/11/1979 |
| From: | Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 024, 24, NUDOCS 7901250186 | |
| Download: ML19263B951 (2) | |
Text
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7 99 Vepco January ll', 1979
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Mr. James P. O'Reilly, Director Serial No. 024 Office of Inspection & Enforcement PSE&C/LCK,j r. :bep/mc U. S. Nuclear Regulatory Corm 11ssion DocketNoh-339-)
Region II 101 Marietta Street, Suite 3100 Atlanta. Georgia 30303
Dear Sir:
On January 8,1979, a report was made under the provisions of 10CFR50.55(e) concerning a possible deficiency in the calculation of the axial flux shape Fj(z) by the APDMS hardware for North Anna Unit 2.
In accordance with the reporting requirements of 10CFR21, the following information is submitted:
A.
Name and address of reporting individual:
- Mr. E. A. Baum, Executive Manager Licensing and Quality Assurance Virginia Electric and Power Company P. O. Box 26666 Richmond, Virginia 23261 B.
Facility, activity, and/or component affected:
North Anna Power Station, Unit 2 Axial Power Distribution Mor.itoring System (APDMS)
C.
Name of firm constructing the facility or supplying the component, activity or service.
Westinghouse Electric Corporation Water Reactor Divisions P. O. Box 355 Pittsburg, Pennsylvania 15230 D.
Description of defect, deficiency, or failure to comply:
Vepco has determined that the Axial Power Distribution Monitoring System ( APDMS) does not properly account for the in-core mo teable detector background signal when determining the axial flux snape, Fj(z).
Since APDMS does not subtract the background signal from the measured flux signal, it has been determined from a review of North Anna Unit 1 flux map data that the value calculated by APDMS for the peak of the axial flux shape has been in error by as much as 0.4 percent.
However, the calculation of Fj(z) is only non-conservative for values greater than 1.0.
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VWGNA (MCTRIC AND POWf R COVPA**Y T O NI. James P. O'Reilly 5" E " " - 2 E.
Date of determination of reportability:
January 8,1979 F.
Similar components, activities or services:
North Anna Power Station, Unit 1 G.
Corrective action which has been, is being or will be taken, the indi-vidual responsible and the length of time to complete the action:
The equipment is not yet operational.
A permanent solution is currently being discussed in-house and with Westinghouse.
H.
Other inforTriation:
None Any information not available at this time will be submitted in a follow-up letter as a 30-day report.
Should you require further information, please contact this office.
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