ML20092E013
| ML20092E013 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 09/11/1995 |
| From: | Denton R BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-90-05, GL-90-5, NUDOCS 9509150004 | |
| Download: ML20092E013 (3) | |
Text
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Ro:ERT E. DENToN B ltimore Gas and Electric Company Calvert Cliffs Nuclear Power Plant Vice President 1650 Calvert Cliffs Parkway Nuclear Energy Lusby, Maryland 20657 410 586 2200 Ext.4455 Local 410 260-4455 Baltimore l
September 11,1995
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U. S. Nuclear Regulatory Commission l
Washington, DC 20555 ATTENTION:
Document Control Desk f
i
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit No.1; Docket No. 50-317 Supplemental Information; Request for Temporary Relief from ASME Boiler &
Pressure Vessel Code Section XI Requirement IAW-5250 REI'ERENCES:
(a)
Letter from Mr. R. E. Denton (BGE) to NRC Document Control Desk, dated March 23,1995, Request for Temporary Relief from ASME B&PV l
Code Section XI Requirement IAW-5250 l
(b)
Letter from Mr. R. E. Denton (BGE) to NRC Document Control Desk, l
dated August 8,1995, same subject During the ultrasonic inspection of the leaking half-coupling on the Saltwater System discharge header, we discovered that the flaw on the half-coupling had degraded. Because of the continued degradation of the flaw, we want to have the option to install a temporary non-Code repair on the half-coupling in accordance with Generic Letter 90-05. %crefore, we amend our previous request for Code relief (References a and b) l to allow the use of a temporary non-Code repair on the affected component.
_DEj_CRIPTION E
A descnption of the leaking half-coupling was provided in Reference (a). The additional degradation was discover x1 by the team performing the follow-up ultrasonic examination of the saltwater pipe in the area of the half coupling. %e half-coupling now has a visible through-wall hole at the location of the presious flaw. He flow of water from the hole has not changed substantially because as the flaw has continued to degrade, the resultant hole has become clogged with biological growth.
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Document Control Desk September 11,1995 Page 2 In order to prevent leakage into the service water room from the continued degradation of the half-coupling, we plan to install a rubber lined pipe clamp around the flawed portion of the half-coupling (see ) should the leakage significantly increase. The clamp will have no affect on the structural integrity of the 36" saltwater pipe, and is a reversible leakage limiting device.
EVALUATION We provided the analyses required by Generic Letter 90-05 in Reference (b). The proposed pipe clamp will not affect the resu' ; of any of those analyses.
AUGMENTED INSPECTION In accordance with the guidance in Generic Letter 90-05, five other half-coupling locations believed to be I
susceptible to the same degradation mechanism will be selected and will be visually examined at the time l
we install the pipe clamp. In the meantime, we are performing periodic walkdowns of the system which would identify serious degradation in similar locations.
SCIIEDULE We have not installed the pipe clamp on the half coupling because there is little leakage from the flaw.
Ilowever, we plan to install it if the leakage from the flaw significantly increases. Because biological growth at the flaw location is a contributing factor, we are uncertain when the pipe clamp might be needed.
Therefore, we request approval ofits use as soon as possible.
Should you have questions regarding this matter, we will be pleased to discuss them with you.
Very truly yours, psn V '
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CilC/ PSF / dim i
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cc:
D. A. Brune, Esquire R. E. Denton J. E. Silberg, Esquire Vice President - Nuclear Energy L. B. hiarsh, NRC D. G. hicDonald, Jr., NRC T. T. hf artin, NRC P. R. Wilson, NRC R. I. Niclean, DNR J. II. Walter, PSC
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