ML19332C401
| ML19332C401 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 11/21/1989 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 89-480A, NUDOCS 8911280077 | |
| Download: ML19332C401 (2) | |
Text
0 ha 1
4 s
<p
..c. N'
-VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 q.
.i November 21, 1989
- U. S. Nuclear Regulatory Commission Serial No.
89 480A Attn: Document Control Desk NO/TAH:Jmj
. Washington, D. C. 20555 Dockat Nos. 50-338 50-339L License Nos. NPF-4 i
. NPF-7 Gentlemen:
._.n VIRGINIA ELECTRIC - AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 and 2 i
TECHNICAL SPECIFICATION CHANGE REQUEST T.S. 3/4-7.6 - FLOOD PROTECTION SUPPLEMENTAL INFORMATION On. October 13,' 1989;(Serial.No. 89 480), Virginia Electric and Power Company
. requested an amendment in the form of changes to the Technical Specifications of.the -
' Operating Licenses No,' NPF-4 and NPF-7 for North Anna Power Station Units 1 and 2.
The proposed changes modify Action Statement 3-7.6 and Surveillance Requirement 4-7.6 regarding. Flood Protection.
4 L
- Thel NRC North Anna Project Manager recently requested additional information.
concerning the design of the flood control dyke and the impact of rain water accumulation L
within the area onclosed by the dyko on safety related equipment. We have provided the -
requested information below.
The flood control dyke is of earthen construction to the west of the Unit 2 Turbine Building.
The dyke creates a " bowl" which will accumulate precipitation. To allow for drainage of L
this accumulation, a pipe has been installed through the dyke. This pipe has a manual L
' valve, which ls operated from within the enclosed bowl area, and an in-series check valve. 'To ensure that water will not enter the bowl area and then the Turbine Building j
during flooding of the main reservoir. the valve in the pipe must be closed during extreme rainfall conditions. The check valve provides redundant isolation.
Q12eoo77e91121
' 0 ADOCK 05ooo338
'p' PDC
I After the valve has been closed, rain falling directly into the bowl area and runoff from the
- Turbine and Service Building roofs will accumulate in the bowl. This has been calculated
.to accumulate to the point where it will enter the Turbine Building basement and fill to a
. maximum elevation of 256 ft. Since the safety related equipment, that could be affected by flooding from the Turbine Building, is protected to an ~ elevation of 257 ft, by flood -
)
barriers at the doorways, flooding is not a safety concern. In addition, there are three non-safety grade pumps in each of the three Turbine Building sumps. Each of these pumps has a flow capacity of 1300 gpm with a discharge head of 57 feet.
If'you have further questions or require additional information, please contact us-immediately.-
Very truly yours, W. L. Stewart Senior Vice President - Nuclear cc: U. S. Nuclear Regulatory Commission 101 Marietta Street, N.W.
Suite 2900 Atlanta, Georgia 30323 Mr. J. L. Caldwell NRC Senior Resident inspector North Anna Power Station Commission Department of Health Room 400-109 Governor Street Richmond, Virginia 23219
_ _