ML18138A089
| ML18138A089 | |
| Person / Time | |
|---|---|
| Site: | Surry, North Anna  |
| Issue date: | 03/14/1980 |
| From: | Stallings C VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Harold Denton, Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| 154-022580, 154-22580, NUDOCS 8003180297 | |
| Download: ML18138A089 (4) | |
Text
e VIRGINIA ELECTR.IC AND POWER COMPANY Rrc:HMoND,V:rxo:rNIA 23261 March 14, 1980 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation Attn:
Mr. Darrell G. Eisenhut, Serial No.
154/022580 PO/FHT:baw Docket Nos: 50-280 50-281 50-338 50-339 Acting Director Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D. C.
20555 License Nos: DPR-32 DPR-37 NPF-4 CPPR-78
Dear Mr. Denton:
Primary Coolant System Pressure Isolation Valves North Anna Power Station Units 1 and 2 Surry Power Station Units 1 and 2 In response to your letter concerning LWR primary coolant system in-series check valves isolating the high pressure primary coolant from the low pressure injection system piping, the following information is supplied for North Anna Units 1 and 2:
(1)
The valve configuration for the interface between the high pressure primary coolant system and the low pressure injection system piping consists of two check valves in series with a MOV.
Figure 1, attached, illustrates the valve configuration.
(2)
The first set of parallel check valves (1-SI-83, 86 and 89 in Figure
- 1) immediately downstream from the primary coolant system have been checked.for leakage in the past by a pressure increase method, once per 18 months pursuant to T.S. 4.0.5 and commitments made to NRC Office of Nuclear Regulation via Vepco letter Serial No. 052C dated August 10, 1977.
This method is described below.
(a)
(b)
(c)
The primary system is pressurized to approximately 1000 psig.
The piping downstream of the check valves is depressurized to one half the as-found pressure.
(The last test vented to approximately 60 psig) and the line is isolated by closing the MOV's as shown in Figure 1.
Venting is terminated for 15 minutes and the pressure on the downstream side of the valves is monitored.
e VIRGINIA ELECTRIC AND PowER Co!dPA:-.Y To Mr. Harold R. Denton 2
In the last test performed on North Anna Unit 1 on January 10, 1980, pressures increased 5 to 30 psig indicating a very small leak :rate.
The second set of parallel check valves (l-SI-195, 197, 200 on Figure
- 1) and the MOV's (1890C and D in Figure 1) are checked for leakage by type "C" testing once per 18 months pursuant to T.S. 3.6.1.2.
The last type "C" test was completed on April 24, 1979, with acceptable results.
(3)
The test on the first set of parallel check valves immediately downstream from the primary coolant systems described above will be modified to maintain the downstream pressure at approximately 100 psig by venting during a test period of approximately one hour.
All drainage vented will be collected and the leak rate of each check valve calculated to determine acceptability.
This method has the advantage of directly measuring leakage.
Type "C" testing performed on the other check valves and MOV's is considered adequate proof of integrity.
With regard to Surry Power Station, Units 1 and 2, information concerning
.. periodic testing t9 insure the integrity of primary coolant pressure boundary isolation check valves was forwarded in our letter Serial No. 030/121779, dated February 7, 1980, addressed to the attention of Mr. A. Schwencer.
Our letter was in response to Mr. Schwencer's letter of December 17, 1979, concerning this subject.
If you have any questions or require additional information, please contact this office.
Very truly yours,
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C. M. Stallings Vice President-Power Supply and Production Operations
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CCMMONWEALTH OF VIRGINIA CITY OF RICHMOND
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Before me, a Notary Public, in and for the City and Common-wealth aforesaid, today personally appeared C. M. Stallings, who being duly sworn, made oath and said (1) that he is Vice President-Power Supply and Production Operations, of the Virginia Electric and Power Company, (2) that he is duly authorized to execute and file the foregoing statements in behalf of that Company, and (3) that the statements are true to the best of his knowledge and belief.
Given under my hand and notarial seal this J 7 1/, day of
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- My Commission expires
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