ML20028A514
| ML20028A514 | |
| Person / Time | |
|---|---|
| Site: | McGuire  |
| Issue date: | 11/17/1982 |
| From: | Tucker H DUKE POWER CO. |
| To: | Adensam E, Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8211220252 | |
| Download: ML20028A514 (2) | |
Text
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DUKE POWER GOMPANY P.O.190X 33180 oIIARLorrE, N.o. 28242 IIAL H. TUCKEH TELEPHONE vw.m parerne=t (704) 373-4531 November 17, 1982
===-c-Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention:
Ms. E. G. Adensam, Chief Licensing Branch No. 4 Re: McGuire Nuclear Station Docket Nos. 50-369, 50-370
Dear Mr. Denton:
On November 5, 1982 McGuire Unit 1 was shut down after operating for 3 months.
This operating period included 720 hours0.00833 days <br />0.2 hours <br />0.00119 weeks <br />2.7396e-4 months <br /> at power levels between 50 percent and 75 percent. The basis for this period of operation was described in my letter of August 3, 1982.
During this shutdown eddy current testing (ECT) of Rows 47, 48 and 49 in all four steam generators was performed. Additionally, in steam generator A, Row 46 was inspected due tc the fact that more indications were observed in steam generator A.
Based on this ECT examination, a total of six tubes were plugged, five in uteam generator A and one tube in steam generator C.
The tube plugged in steam generator C (R49-C40) had the largest observed wear scar (420 percent) a t. the last inspection and was expected to be plugged during the November outage.
This tube had worn to approximately 40 percent through-wall.
The five tubes plugged in steam generator A all exhibited indications of '"25 per-cent. These tubes were plugged since their projected wear rates would increase the indications to greater than 40 percent through-wall with another operating cycle similar to the August to November cycle just completed. No tubes were plugged in steam generators B and D.
A detailed tube by tube listing of the ECT results is being prepared for sub-mittal to the NRC Staff. This submittal will include Duke Power Company's evaluation of tube wear rates and a proposed program for operation of McGuire above 50 percent power,1f warranted. In the interim we have concluded that the unit can be operated at 50 percent power with no significant steam generator tube wear. This conclusion is based on:
- 1) Results of ECT conducted af ter operation at 50 percent power f
in November 1981, and
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- 2) Results of ECT conducted at Almaraz after 3000 hours0.0347 days <br />0.833 hours <br />0.00496 weeks <br />0.00114 months <br /> at 50 percent i
power In the case of Almaraz, it should be noted that no additional tube degradation was observed after 3000 hours0.0347 days <br />0.833 hours <br />0.00496 weeks <br />0.00114 months <br /> at 50 percent power, since Almaraz had previously 2 821117 P
050003g9 PDR
r Mr. Harold R. Denton, Director November 17, 1982 Page 2 experienced accelerated tube wear and has been operating with worn tubes.
The proposal contained in this letter is similar to that in William O. Parker, Jr.'s i
letter of July 13, 1982.
Mr. Darrell Eisenhut's letter of July 19, 1982 transmitted the Staff's evaluation of this previous proposal. In our view this evaluation is applicable to the current proposed 50 percent power operation.
The current schedule is to have McGuire Unit 1 back on line November 22, 1982.
Therefore, an expedited review of this proposal is requested. Please advise if there are any questions regarding this matter.
Very truly yours, s#~
'c&d k-4 4e.,
Hal B. Tucker GAC/php cc: Senior Resident Inspector McGuire Nuclear Station i
Mr. James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Comnission Region II 101 Marietta Street. Suite 3100 Atlanta, Georgis 30303 l
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