ML19254F263

Interim Deficiency Rept Re Overpressurization of Containment from Main Steam Line Break.Util,B&W & S&W Investigating Mods to Auxiliary Feedwater Sys to Limit Flow to Broken Steam Generator in Event of Main Steam Line Break

ML19254F263
Person / Time
Site:	North Anna
Issue date:	09/07/1979
From:	Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
References
REF-PT21-79-147-000 NUDOCS 7911070441
Download: ML19254F263 (2)

Text

.

y-

/ cm A tLECTRIC AND POWER COMP ANY, RICMMON D, VIRGINI A 23261 3f 19 AfD . 2 4 September 7, 1979 Mr. James P. O'Reilly, Director Serial No. 724 Office of Inspection & Enforcement PSE&C/WBR:mac: wang U. S. Nuciear Regulatory Commission Region II Docket Nos. 50-404 101 Marietta Street, Suite 3100 50-405 Atlanta, Georgia 30303

Dear Mr. O'Reilly:

On September 4, 1979, a report was made under the provisions of 10CFR50.55(e) concerning overpressurization of the contairment from a main steam line break.

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 Richmond, Virginia 23261 B. Facility, activity, and/or component affected:

North Anna Power Station, Units 3 & 4 C. Name of fim constructing the facility or supplying the component, activity or service:

Stone & Webster Engineering Corporation P. O. Box 2325 Boston, Massachusetts 02107 D. Description of defect, deficiency, or failure to comply:

The original PSAR analyses did not consider the long term blowdown from t main steam line break. Later afialyses show that the long term blowdown will overpressurize the containment.

E. Date of determination of reportability:

September 4, 1979 1'"2 225

• 7 91LO70 b b

'(90/o /

OMYXAL OOPY S

F. Similar components, activities, or services:

None G. Corrective action which has been, is being or will be taken, the individual responsible and the length of time to complete the action:

Vepco, S&W and B&W are investigating modifications to the auxiliary feedwater system to limit auxiliary feedwater flow to the broken steam generator in the. event of a main steam line break.

H. Other infomation:

None Any information not available at this time will be submitted in a follow-up letter as a 30-day renort.

Should you require further ir. formation, p ' ease contact , his office.

Ver- uly ou'rs / /,

- Ul '

C. Brown, Jr.

Senior Vice President - Power Sta io Engine ingandConstruction(

cc: Director, Office of Inspection and Enforcement (3)

/

' " 2 226

.-