ML19263D745
| ML19263D745 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 04/06/1979 |
| From: | Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 230, NUDOCS 7904130214 | |
| Download: ML19263D745 (2) | |
Text
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VIRGINI A ELECTRIC AND POWER COMP ANY, RICHMOND, VIRGIN A 23261 April 6,1979 Mr. James P. O'Reilly, D'irector Serial No. 230 Office of Inspection & Enforcement PSE&C/MLM:adw:mc U. S. Nuclear Regulatory Commission Region II Docket No. 50-339 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303
Dear Sir:
On April 4, 1979, a report was made under the provisions of 10CFR50.55(e) concerning a deficiency in the analysis of the departure from nucleate boiling ratio (DNBR) following a single rod drop.
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 & 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 Exceed DNBR Design Limit Following Single Rod Drop C.
Name of firm constructing the facility or supplying the component, activity or service:
Westinghouse Electric Corporation P. O. Box 355 Pittsburgh, Pennsylvar,ia 25230 D.
Description of defect, deficiency, or failure to comply:
In the event of a single dropped rod, the automatic rod control system responds to the indicated power reduction by withdrawing the control rods to restore the steady state power le 9 If a dropped rod is near the automatic rod control sys%n se.. or, the sensor will perceive a greater power reduction than representative for the core and attempt to overcompensate on the subsequent centrol bank withdrawal.
The potent.ial resulting power overshoot could result in calculated violation of the plant DNBR limit.
790413 0 c2/ f
Mr. James P. O'Reilly ssecT wo.
2 VIRGINIA ELECTRIC AND POWER COMPANY TO E.
Date of determination of reportability:
April 3, 1979 F.
Similar components, activities, or services:
North Anna Unit 1 G.
Corrective action what has been, is being or will be taken, and indi-vidual responsible and the length of time to complate the action:
Westinghouse is presently performing the required analysis for the single rod drop event. Westinghouse plans to meet with the appropriate members of the NRC staff to review their recent findings concerning this deficiency and to determine a reasonable course of action to update the safety analyses for this event on a plant-by-plant basis.
H.
Other infomation:
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, pl ase contac this office
]/-
Very ly our, /
I-t
[
am. Brov, Jr.
Vic President - Power St tion En neering and Construc ion lete:
Director, Office of Inspection and Enforcement (3)
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