ML19093A974
| ML19093A974 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 11/22/1977 |
| From: | Stallings C Virginia Electric & Power Co (VEPCO) |
| To: | Case E, Reid R Office of Nuclear Reactor Regulation |
| References | |
| Download: ML19093A974 (2) | |
Text
,-
Mr. Edson G. Case, Acting Director Nuclear Reactor Regulation Serial No. 528 PO&M/TAP:dgt Docket Nos. 50-280 U. S. Nuclear Regulatory Commission Washington, D. C.
20555 50...:281 Attention:
Mr. Robert W. Reid, Chief Operating Reactors Branch 4 License Nos. DPR-32 DPR-37
Dear Mr. Case:
On November 18, 1977, Surry Unit No. 2 was shutdown due to a primary to secondary leak slightly greater than 0.3 gpm in "A" steam generator.
After shutdown "B" and "C" steam generators were hydrotested and no tube leakage was found.
The only tube *leaking in "A" steam generator was R5-C26.
This tube did not pass a 0.650 inch probe in March of 1977 and is now in the re-gion of predicted strain of greater than 15% and does not pass a 0.540 probe.
A review of the records from the September 1977 outage found this tube was scheduled to be inspected but was not.
To assure that additional tubes were not missed, the following reviews of past data were made:
- 1)
For all tubes which did not pass the 0.650 probe during the March 1977 inspection, the data was reviewed to assure that they were inspected in September 1977.
This consisted of 190 tubes in A, 123 tubes in B, and 108 tubes in C.
The results of this review showed that the Row 5 Col. 26 tube of A was the only scheduled tube not inspected in September.
2).
A sampling of data sheets versus strip chart results was done to monitor the accuracy of the data sheets.
This consists of.15% of the tubes inspected in A, 12% in Band 15% in C.
There were no differences found between the data sheets and the strip chart records.
The results of the above reviews give a high assurance that no further scheduled tubes were missed.
To improve the ititure accuracy of our steam generator inspection program: any tube which does not pass a 0.650 probe will be probed at all future scheduled inspections; the tubes which are part of the gauging program will be re-checked at the end of the program by comparing strip *charts with data sheets.
During the shutdown, the following tubes surrounding the leaker were gauged and all passed a 0.650 probe:
e Vrn.sINIA ELECTRIC AND POWER COMPANY TO
- Hr. Edson G. Case Page 2 Row 6 Col. 26 7
26 4
27 5
27 6
.27 7
- 27 4
28 5
- 28.
6 28 7
28 The following tubes in "A" steam generator were plugged in accordance with the criteria stated in our letter of September 30, 1977:
Row 5 Col. 26 Row 6, 7 Col. 26 Row 4,5,6 Col. 27
- leaker and would not pass*a 0.540 probe two tubes beyond any tube in col. 15~79 which does not pass a 0.540 probe tubes surrounding a leaker The following.tubes were plugged in 11C" steam generator since they were missed during the September 1977 out.age:
Row 38 34 33 33 Col.. 73 73 75
.77 We request that operation of Surry Unit No. 2 be permitted in accordance with the order of October 8, 1977.
Thee health or safety of the public will not be adversely affected as the safety evaluation for the order remains valid.
cc: Mr. JamesP. O'Reilly Very truly yours,*
Z/J. )JI), v&tft~~
C. M. Stallings Vice President-Power Supply and Production Operations I
I J