ML20062M510
| ML20062M510 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 12/11/1981 |
| From: | Rausch T COMMONWEALTH EDISON CO. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0619, RTR-NUREG-619 NUDOCS 8112170271 | |
| Download: ML20062M510 (2) | |
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'1. Commonwealth Edison l
) one First NationJl Plan C,hjcago.pnots d
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7 Address Reply to: Post Oifice Box 767
,- Chicago Illinois 60690
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December 11, 1981-
. -Q lP 62[jf((i S
Mr. Darrell G. Eisenhut, Director 0602 g IO8lah,gg '
Division of Licensing g
U.S. Nuclear Regulatory Commiasion
-e u Washington, DC 20555 N,5kbN Q
sE7 I
Subject:
Quad Cities Station Unit 2 N
Control Rod Drive (CRD)
Return line Isolation Associated with NUREG 0619 NRC Docket No. 50-265 References (a):
R. F. Janecek letter to D. G.
Eisenhut dated February 23, 1981.
(b):
T.
A.
Ippolito letter to L. O.
DelGeorge dated November 2, 1981.
(c):
T. J. Rausch letter to D. G.
Eisenhut dated November 15, 1981.
Dear Mr. Eisenhut:
In Reference (a), Commonwealth Edison committed to close the two isolation valves on the Quad Cities Unit 2 CRD return line (if leak testing proved that no cold water had been reaching the nozzle) and install a tell-tale-drain line between the two valves.
Reference (b) acknowledged our position and requested that we inform the NRC within 30 days of letter receipt if we do not initiate leak-detection concurrent with the double-valve isolation this present outage.
As we indicated in Reference (c), leak testing performed th.is outage on the 2-301-74 valve resulted in no leakage at a 25 psig test pressure (normal DP is approximately 10 psid).
Operation-ally, an -open tell-tale drain is not desirable because this will result in a differential pressure across the isolation valves of 1000 psig or more.
These valves are not designed to be leak-tight at these DP valves.-
Should an open tell-tale drain be installed, leakage past 2-301-94 would result in Reactor water going directly to Radwaste.
This is not desirable.
Leakage past 2-301-74 and 2-301-94' would result in unwanted water inputs to Radwaste requiring processing.
This is not a proper means to effect a program of
. reduced inputs to Radwaste reduced solid and liquid effluents from 8112170271 81121'E
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PDR AbOCK 05000265 K gj j P
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D. G. Eisenhut December 11, 1981 Radwaste.
Investigations were performed to use the local pressure indicator located between the two valves.
No conclusions could be derived based on the readings that this instrument would provide.
Any permarent and complicated modification to provide quantified leakage data would necessitate many engineering, design, procurement and installation manhours.
Our outage schedule does not allow for this.
Because of the above concerns, a tell-tale drain will not be installed on the CRD return line this outage.
Both valves, 2-301-74 and 2-301-94 shall be locked closed, however, and admini-strative and procedural controls are in place to prevent their opening during normal plant operation.
In order to further assure that cold water flow did not reach the CRO return nozzle during normal operation, a leakage test will be performed on the isolation valves each refueling outage.
Should both valves be found to not be leak-tight, then the CRD return nozzle would again be dye penetrant tested (and repaired if necessary).
This commitment will provide an equal or greater margin of safety tr.an our previous position, and was discussed with the NRC Quad Cities Project Manager on December 3, 1981.
We have initiated an engineering investigation of an alternate leax detection method utilizing thermocouples.
At the time we employ any suitable on-line leak detection method, we will discontinue future refueling outage valve leakage tests unless leakage is suspected.
Please address any questions you may have concerning this matter to this of fice.
One (1) signed original and thirty-nine (39) copies of this transmittal are provided for your use.
Very truly yours, h
u ah Go Thomas J. Rausch Nuclear Licensing Administrator Boiling Water Reactors cc:
Region III Inspector - Quad Cities im 3032N