ML19326D595
| ML19326D595 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 06/23/1980 |
| From: | Schwencer A Office of Nuclear Reactor Regulation |
| To: | Parris H TENNESSEE VALLEY AUTHORITY |
| References | |
| NUDOCS 8007020722 | |
| Download: ML19326D595 (3) | |
Text
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f*M UNITED STATES
"'t, NUCLEAR REGULATORY COMMISSION
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June 23, 1980
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Docket Nos. 50-327 and 50-328 Mr. H. G. Parris Manager of Power
. Tennessee Valley Authority 500A Chestnut Street, Tower II Chattanooga, Tennessee 37401
Dear Mr. Parris:
SUBJECT:
COMMITMENTS FOR SEQUOYAH, UNITS 1 AND 2 As part of our continuing licensing review of the Sequoyah, Units 1 and 2 application, we find that we need your comitment, within five days of receipt of this letter, to agree to perform the required actions described in the enclosure.
Sincerely,
. Schwencer, Chief Licensing Branch No. 2 Division of Licensing
Enclosure:
As stated cc: See next page r
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80070207A A i
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Mr. H. G. Parris Manager of Power Tennessee Valley Authority 500A Chestnut Street Tower II Chattanooga, Tennessee 37401 cc: Herbert S. Sanger, Jr...Esq.
General Counsel.
Tennessee Valley Authority 400 Comerce Avenue E 11B 33 Knoxville, 'elnessee 37902 Mr. H. N.
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Tennessee s v
'thority 400 Commencs * -
'49A HBB Knoxville, Teni...;<.
37902 Mr. Bob Faas Westinghouse Electric Corporation P. O. Box 355 Pittsburgh, Pennsylvania 15230 Mr. Mark Burzynski Tennessee Valley Authority 400 Chestnut Street Tower II Chattanooga, Tennessee 37401 Mr. J. F. Cox Tennessee Valley Authority 400 Commerce Avenue, W10C131C Knoxville, Tennessee 37902 Resident Inspector /Sequoyah NPS c/o U.S. Nuclear Regulatory Commission P. O. Box 699 Hixson, Tennessee 37343 b
c.
o ENCLOSURE i
COMMITMENTS ON SEQUOYAH, UNITS 1 AND 2 Steam Generator Inspection Ports For some forms of steam generator degradation which have occurred, eddy current testing 'and tube gauging alone~ are not sufficient to' assess and monitor tube support plate degradation. In order to perform adequate assessment and monitoring of these areas, it is necessary to install inspection ports. These ports should be installed just above the upper support plate and between the tubesheet and the lower support plate and in line with the tube lane.
Under the As Low As Reasonably Achievable (ALARA) concept, we have been requesting that all possible steam generator modifications be made before the start of operations in order to minimize personnel exposure. Based upon experience at Surry 1, the ports can be installed in three steam generators at a total personnel exposure of 7.5 man-rem.
On this basis, although installation prior to initial operation is perferable, we have determined that the potential installation exposure following the first cycle of operation is not significant enough to justify the delay of the initial start-up of the plant to permit the installation of inspection ports. However, since seco.!dary side contamination will increase as the operating time increases, we require that these ports be installed prior to start-up after the first refueling.
Row 1 Steam Generator Tubes Experience has shown that the small bend radius of the Row I tubes in the steam generators of Westinghouse design leads to early onset of cracking. At the present time, Westinghouse has committed (letter from T. M. Anderson to R. H. Vollmer, May 12, 1980) to a program to determine the particular susceptibility of Row 1 tubes to cracking.
The program involves removing numerous tubes from the Trojan plant and subjecting them to non-destructive and destructive testing to _
identify the cause of the cracking and to develop a field inspection method capable of detecting potential leaking tubes. The results of this evaluation are expected to be available in October 1980. We will review the program results and decide at that time on the necessity to plug the Row 1 tubes.