ML19326E191
| ML19326E191 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 07/25/1980 |
| From: | Sylvia B VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Harold Denton, Youngblood B Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8007280423 | |
| Download: ML19326E191 (2) | |
Text
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A VInorNrA EE.ECTRIC AND Pownu COMPANY Hrcumown,VrmorwzA 20262 July 25, 1980 Mr. Harold R. Denton, Director Serial No. 641 Office of Nuclear Reactor Regulation N0/FHT:ms Atta:
Mr. B. Joe Youngblood, Chief Docket No. 50-339 Licensing Branch 1 License No. NPF-7 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C.
20555
Dear Mr. Denton:
PERIODIC LEAK TESTING OF PRESSURE ISOLATION VALVES NORTH ANNA POWER STATION UNIT NO. 2 In response to a request from members of your staff, we are providing the attached additional information on the above subject.
If you have any questions or require additional information, please contact this office.
Very truly yours, O
V B. R. Sylvia Manager - Nuclear Operations and Maintenance Attachment ec:
Mr. James P. O'Reilly Office of laspection and Enforcement Region II Atlanta, Georgia 30303 8maso123 g
Attschm:nt NORTH ANNA UNIT 2 Wc ~ have completed a preliminary review of the SER Supplement entitled
" Periodic Leak Testing of Pressure Isolation Valves."
Our response to the suggested comitments are as follows:
1.
The systems which have the subject design configurations include high head and low head safety injection, safety injection accumulators, and the RHR system.
a.
We agree to a leakage limit of 1 gpm for testing of the pressure isolation valves in the high head and low head safety injection systems.
b.
In the case of the accumulators, leakage past the accumulator pressure isolation valves would result in an increase in accumulator level which would be alarmed and rapidly identified by the control i
room operator.
The leakage test system configuration tests the accumulator check valves at reduced differential pressure. We will leakage limit equivalent to 1 gpm per valve at normal commit to a RCS pressure.
This leakage limit will be sufficient to quickly identify any signif4. cant deterioration in valve seating capability.
c.
The RHR system has two pressure interfaces, inlet from the RCS and return to the RCS.
These valves do not have leak test connections presently installed.
For the RHR inlet valves, 2 MOV's in series, leaksge estimates will be obtained by an RCS leakage measurement at reduced differential pressure while alternately exposing each of the inlet MOV's to the differential pressure.
This method will provide a leakage estimate adequate' to determine if any significaut valve deterioration has occurred.
We commit to a leakage limit of 5 gpm per valve which is consistent with the RCS leakage measurement capabilities at reduced pressure.
The RHR return valves, two MOV's in parallel, will be tested at reduced pressure using the accumulator as the pressure source.
The leakage limit for these valves will also be 5 gpm per valve which is sufficient to identify any significant valve deterioration.
We will install test connections on the RHR inlet and return valves prior to start up of Unit 2 from the first refueling outage. This i
will enable us to perform more accurate leak rate measurements.
j l
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d.
We commit to categorizing the RHR valves as Category A.
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