ML20244D519
| ML20244D519 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 06/09/1989 |
| From: | Trevors G NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| CNSS897134, NUDOCS 8906190109 | |
| Download: ML20244D519 (2) | |
Text
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COOPER NUCLEAR ST ATtoN
,,,;. 7,
4 Nebraska Public Power District
- 9'A*c", *"~EWi&^Y^ "'"
________.________.__m CNSS897134 June 9, 1989 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555
Subject:
Containment Purge and Vent Valve Leak Testing Cooper Nuclear Station NRC Docket No. 50-298, DPR-46
Reference:
Letter, G. A. Trevors to NRC, " Containment Purge and Vent Valve Leak Tecting", dated February 19, 1988.
Gentlemen:
As stated in the referenced letter, quarterly local leak rate tests were performed on the containment purge and vent valves at Cooper Nuclear Station.
The results of these leak rate tests and the L impact are shown below. These figures represent the minimum pathway leakage.a TYPE "B" AND "C" 1988 1988 1988 1989 PRIMARY CONTAINMENT AS-LEFT FIRST SECOND AS-FOUND LEAKAGE PATHWAYS LEAKAGE QUARTER QUARTER LEAKACE X-25, Drywell Inlet 0.00 SCFH 0.33 SCFH 0.55 SCFH 3.35 SCFH3 X-26, Drywell Exhaust 8.03 SCFH 69.83 SCFH 72.96 SCFH 0.00 SCFH3 X-205, Torus Inlet 0.29 SCFH 0.18 SCFH 0.14 SCFH 25.81 SCFH X-220, Torus Exhaust 0.18 SCFH 0.69 SCFH 1.57 SCFH 2.38 SCFH Other Penetrations 31.96 SCFH 31.96 SCFH 31.96 SCFH 113.41 SCFH Total (All Type B&C) 40.46 SCFH 102.99 SCFH 107.18 SCFH 144.95 SCFH Per Cent of L 12.8%
32.6%
33.9%
45.9%
a 1.
1988 As-Left from the 1988 Refueling Outage.
2.
1989 As-Found from the 1989 Refueling Outage.
3.
Blank installed to determine actual minimum pathway leakage.
0 8906190109 890609 PDR ADOCK 05000298 P
I Nugicer Regulatory Commission I
- l ' fby 31, 1989 l
Page 2 Af ter the 1989 as-found tests, an inspection of the upstream side of the drywell and torus inlet lines was performed.
Apparently, dirt had blown across the purge inlet valve seats from the ventilating system while de-inerting the containment for the 1989 Refueling Outage.
Subsequent closing of the valves to perform the local leak rate tests damaged the rubber seat rings, causing higher leakage rates than vere recorded for the tests performed during operation.
Sincerely, i
G.
. Trevors Division Manager Nuclear Support GAT:sa cc:
U.S. Nuclear Regulatory Commission Region IV Arl:'ngton, Texas NRC Resident Inspector Cooper Nuclear Station
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