ML20088A501
| ML20088A501 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 04/04/1984 |
| From: | Rybak B COMMONWEALTH EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 8406N, NUDOCS 8404120127 | |
| Download: ML20088A501 (2) | |
Text
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Commonwrith Edison hf O
One First National Plaza. Chicago. litinois C'
Address Reply to Post Office Box 767 Chicago. Illinois 60690 April 4, 1984 Mr. James G. Keppler Regional Administrator U.S. Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137
Subject:
LaSalle County Station Unit 1 Report on Three Month Cable Inspection for Drywell Temperatures NRC Docket No. 50-373 Reference (a):
C. E. Norelius letter to Cordell Reed dated January 13, 1984.
~
Dear Mr. Keppler:
The referenced letter requested that a report be submitted outlining the findings of the visual inspection of the Unit 1 drywell cables and equipment which was to be performed at approximately three j
months after.the Unit 1 restart in January 1984.
The purpose of this letter is to fulfill that request per the following:
i A.
Basis for Drywell Cable Inspections.
5 The basis of the three month inspection was to examine those cables and equipment which had been deemed affected by high temperaturcs in the Unit 1 Drywell prior to November 1984.
The scope of visual inspection was for the cables which had been replaced prior to Unit 1 restart in January of 1984.
Over 90% of those cables were examined.
j Those cables which were replaced all the way back to the drywell penetrations were inspected only at available locations above the 796 foot elevation.
Those that were spliced in Junction Boxes below the 796 foot elevation were inspected at available locations from the splice point up to the instrument.
The inspection of the drywell snubbers was performed under the requirements of the Technical Specification surveillance program.
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f J. G. Keppler April 4, 1984 B.
Findings of Visual Inspection.
All Safety Related cables inspected above the 796 foot elevation were examined in at least two different locations and showed no visible degradation of the cable insulation.
From the sampling of non-safety related cables only three cables showed evidence of heat induced degradation of the insulation.
All three cables go to temperature sensors.
The first sensor monitors the annulus outlet temperature, the second sensor monitors the upper elevation air temperature while the third cable is for stem leakage from a RCIC line.
All three cables are routed thru areas or installed in areas which are considered local hot spots based on the data from the Stations Temperature Monitoring Program.
All other cables inspected in the area of the heat damaged cables were found to be in a satisfactory condition.
All the snubbers which were listed in the December 22, 1983 letter to the Region III Headquarters as being replaced, were visually and functionally inspected and found to be in a satisfactory condition.
C.
Conclusion The snubbers and Safety Related cables inspected do not show heat damage.
The 3 nonsafety related deficiencies are very localized and require a long term solution such as rerouting the cable / sensor or a more heat resistant cables if the sensor can't be relocated.
The deficiencies were repaired and heat shrink added to provide more protection and will be inspected again during the additional inspection required in the referenced letter.
The drywell temperature data continues to show good results of substantially reduced upper level drywell temperatures demonstrating the interim HVAC modification effectiveness.
If there are any questions regarding this matter, please contact i
this office.
Very truly yours, M6
/
B.
bak
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Nuclear Licensing Administrator 1m I
cc:
Region III Inspector - LSCS 8406N
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