ML17201M348
| ML17201M348 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities, 05000000 |
| Issue date: | 02/01/1989 |
| From: | Miller H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Reed C COMMONWEALTH EDISON CO. |
| Shared Package | |
| ML17201M381 | List: |
| References | |
| NUDOCS 8902070074 | |
| Download: ML17201M348 (2) | |
Text
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Docket Nos. 50-237, 50-249 50-254, and 50-265 Commonwealth Edison Company ATTN:
Mr. Cordell Reed Senior Vice President Post Office Box 767 Chicago, IL 60690 Gentlemen:
FEB l 1989
SUBJECT:
ENVIRONMENTAL QUALIFICATION OF BUTYL RUBBER INSULATED CABLE AT DRESDEN UNITS 2 AND 3, AND QUAD CITIES UNITS 1 AND 2
References:
(a) Letter from H. J. Miller to Cordell Reed, dated July 6, 1988.
(b)
Letter from H. E. Bliss to A. B. Davis, dated August 5, 1988.
(c) Letter from I. M. Johnson to A. B. Davis, dated September 22, 1988.
In reference letter (a), the NRC indicated that the similarity analyses between the Wyle Laboratories tested 5KV butyl rubber cables and the 600 volt cables did not fully meet the DOR Guidelines and therefore, Environmental Qualification (EQ) had not been adequately established for the 600 volt cables.
Commonwealth Edison Company provided their position regarding the qualification of the 600 volt butyl rubber cables in reference (b), and agreed to implement an augmented surveillance program to monitor the condition of the cables.
In Reference (c),
Commonwealth Edison Company submitted the augmented surveillance program to the NRC.
The NRC's concerns regarding the butyl rubber cable installed at both Dresden and Quad Cities Stations were focused on two distinct issues. First, whether the similarity analyses between the Wyle tested 5KV cables and the 600 volt cables met the DOR Guidelines; and second, the potential for cable degradation via butyl reversion (dependent upon radiation dose rate and thermal oxidation rates).
As we indicated in Reference (a), the second issue is outside the scope of the DOR Guidelines.
The NRC has completed its review of the first issue.
Based on our review of your referenced submittals, we have concluded that the butyl rubber cables installed at Dresden and Quad Cities are qualified for their specific applications in accordance with the DOR Guidelines.
We have no further questions regarding this issue.
In regards to the second issue, your proposed augmented surveillance program does not resolve our concerns regarding butyl rubber cable degradation via butyl reversion.
However, we feel that potential degradation could be monitored provided that certain enhancements were included in your program.
8902070074 890201 PDR ADOCK 05000237 p
Commonwealth Edison Company 2
FEB 1 1989 Therefore, we are proposing that you augment your surveillance program with the enhancements or similar enhancements described in the attachment to this letter.
Unfortunately, little industry or research testing has been conducted regarding butyl rubber reversion, thereby limiting the available knowledge base.
The NRC intends to obtain samples of butyl rubber cable to allow such testing.
Licensees utilizing butyl rubber cable in their facilities in other than mild environments will be encouraged to assist the NRC in resolving this issue by providing samples of butyl rubber cables.
We believe that this is an instance in which a joint industry an.d NRC effort is appropriate to provide a solution to a technical issue.
Should you have any questions regarding this matter, please contact Mr. J. J. Harrison (312/790-5635) or Mr. Ron Gardner of my staff (312/790-5524).
Attachment:
P.roposed Enhancements~Augmented Surveillance Program cc w/attachment:
H. Bliss, Nuclear Licensing Manager J. Eenigenburg, Plant Manager, Dresden R. L. Bax,-Station Manager, Quad Cities DCD/DCB (RIDS)
Licensing Fee Management Branch Resident Inspector, RIII Richard Hubbard J. W. Mccaffrey, Chief, Public Utilities Division RIII
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Gautam 02/ I /89 RI II G~vtner 02/ I /89 Sincerely,
.. '.QRiGIN:AL SIGNED.B.Y. HUBERT J.. MILLER lrl....
H. J. Miller, Director Division of Reactor Safety
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