ML20031A053
| ML20031A053 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 09/11/1981 |
| From: | Delgeorge L COMMONWEALTH EDISON CO. |
| To: | Schwencer A Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8109180334 | |
| Download: ML20031A053 (2) | |
Text
L.,. -
n'N Commonwealth Elson
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na September ll i 1981 4, A
W Mr.
A. Schwencar, Chief L3 censing Branch 2 Division of Licensing U.S. Nuclear Regulatory Commission Washington, DC 20555 Subiect:
LaSalle County Station Unit 1 and 2 Electrical Separation Review NRC Docket Nos. 50-373/374
Dear Mr. Schwencer:
The purpose of this letter is to document a ver'al u
commitment made in a telephone conference with Mr.
A.
Bournia of your staff on September 4, 1981 related to the LaSalle County electrical separation review.
As you are aware, Commonwealth Edison has submitted in the discussion of RG 1.75 in Appendix B of the FSAR a justification of the separation criteria employed at LaSalle County.
It is our understanding that with limited exception that discussion resolved the NRC Staff's concerns.
The exceptions involve the separation existing between nonsafety related cable pans and safety-related cable pans in general plant areas.
Specifically, the issue is whether the separation existing at LaSalle County is adequate to prevent damage to safety-related cables as a result of faults induced in the nonsafety pans.
In order to resolve this concern, Commonwealth Edison provided the Staff with color-coded drawings showing every location in the plant where the separation was less than that proposed in RG 1.75.
Those limited instances of potential interaction were argued
- o have no safety impact due to the fact that in no instance could a fault in r single nonsafety related pan induce a failure affecting redundant safety-related equipment.
Furthermore, in Reference (1),
Commonwealth Edison demonstrated by reference to testing performed for the NRC that the postulated fault induced damage was unlikely to occur for configurations similar to those at LaSalle County due to the general use of solid bottom cable pans and IEEE-383 cable in both safety and nonsafety related cable applications.
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PDR ADOCK 05000373 7'
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L. However, in order to provide the NRC Staff further justification for the adequacy of the LaSalle County design, Commonwealth Edison shall perform a test of the most limiting pan configuration (s) to validate the conclusion that faults induced in nonsafety related cable will not propogate-to or by heat effects induce the failure of adjacent safety-related cable.
In the event this testing failed to validate the Commonwealth Edison position, modlfications will be made as necessary to provide adequate separation or thermal insulation will be installed to prevent thermal damage from prooogating between nonsafety and safety related pans.
If determined to be required, these modifications will be scheduled for completion prior to startup after-the first refueling outage on LaSalle County Unit 1.
In addition, a copy of the testing i
program will be submitted to your Staff for review prior to start of j
testing.
It is our understanding that this program for resolution is judged by the NRC Staff to adequately resolve the open issue now outstanding on the LaSalle County Unit 1 docket.
If there are any further questions in this regard, please direct them to this affice.
.Very truly yours, L.
O. DelGeorg Director of Nuclear Licensing cc:
NRC Resident Inspector - LSCS I
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