ML20054B810

Expresses Concern W/Accuracy of Sections of NUREG-0886, Steam Generator Tube Experience, Including Table 1 Re Operating Experience W/Pwr Steam Generators Through Nov 1981 & Paragraph 3.3.1 Re Recent plant-specific Problems

ML20054B810
Person / Time
Site:	Farley
Issue date:	04/12/1982
From:	Clayton F ALABAMA POWER CO.
To:	Stolz J Office of Nuclear Reactor Regulation
References
RTR-NUREG-0886, RTR-NUREG-886 NT-82-2099, NUDOCS 8204190220
Download: ML20054B810 (3)

Text

Milling Addrns Alabama Power Company 600 North 18th Street Post Office Box 2641 Birmmgham, Alabama 35291 Telephone 205 783-6081 F. L. Clayton, Jr. b

$n"tEEgNoT"' Alabama Power NT-82-2099 a soam eu mc snmm Docket Nos. 50-348 , 9 50-364 4 9'

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April 12, 1982 -

App 3 7 E 157 - ,

Director of Nuclear Reactor Regulation <

y V. S. Nuclear Regulatory Commission - (cc v Washington, D. C. 20555 Attn: Mr. John F. Stolz Joseph M. Farley Nuclear Plant - Unit Nos.1 & 2 Steam Generator Tube Experience as referenced in NUREG-0886 Gentlemen:

We have reviewed your recently issued NUREG-0886 entitled " Steam Gen-erator Tube Experience". During our review, several areas of concern were identified. The following is a discussion of our concerns.

1. Table 1, Operating experience with Westinghouse PWR steam gen-erators through November 1981, pages 18 and 19.

a. Farley 1 is listed as having had eight leaking tubes and eight plugged tubes. Only six tube leaks have occurred. All leakage was below Tech-nical Specification requirements. The leaking tubes were located by hydrostatic testing, and were subsequently plugged. Two other tubes which were examined by eddy current testing (ET) were found to have recordable indications. The in-dications could not be characterized from the evaluation of test data and, although no tube leakage had occurred, the tubes were plugged to prevent future problems.

Farley 1 is also noted in the report as having ex-perienced primary side stress corrosion cracking (SCC) in small radius U-bends. In March 1979, all steam generator C row 1 tubes and various other tubes were examined by ET. The defect in one tube l (which was previously identified as a leaker) was l located at the hot leg side transition from the straight tube length into the U-bend on the first .Op row. All tubes examined, exclusive of the leaker, i

9204190220 820412 1' h O PDR ADOCK 05000348 P PDR

J. M. Farley Nuclear Plant - Unit Nos.1 & 2 Steam Generator Tube Experience as referenced in NUREG-0886 April 12, 1982 Page 2 showed no sign of tube wall degradation, thinning or denting. In December 1980, all steam generator B row I tubes (exclusive of the three tubes which were previously plugged) and row 2 tubes and various other tubes were examined by ET. No indi-cations were found. Of the six leaking tubes (three in steam generator B and three in steam generator C), one tube U-bend defect was found by ET, one leaking tube was examined by ET with no recordable indications found, and four tubes were not examined by ET at the time of leak detection.

Neither the ET results to date nor any other qualitative examination data indicate that Farley 1 has a generic problem with primary side stress corrosion cracking.

b. Farley 2 is listed as having had five leaking tubes and five plugged tubes. Of the five plugged tubes, two tubes were plugged at the Westinghouse factory, and two tubes were plugged during con- -

struction. Therefore, these tubes never leaked.

The leakage rate in the ona remaining tube was be-low Technical Specification requirements. The tube was plugged during initial startup to prevent any future problems.

2. Paragraph 3.3.1, Recent Plant-Specific Problems, Westinghouse Steam Generators, Farley Units 1 and 2, page 24.

a. The statement " Unit 1 previously experienced small, U-bend leaks (below the plant Technical Specification limit) in Row 1 tubes in March,1979 and December,1980" is misleading in that, as men-tioned in paragraph 1.a., only one leaking tube was characterized (in March,1979) as having a U-bend type defect. All Row 1 tubes and Row 2 and 3 tubes adjacent to the leaking tube were examined.

Exclusive of the leaker, all tubes examined showed no sign of tube wall degradation, thinning or denting. The leaking tube found in December,1980 was a Row 1 tube, however the defect was not characterized.

b. In reference te Unit 2, the statement is made that a tube leak in June,1981 "may have been caused by a hacksaw blade which was dropped into the general area while upper inspection ports were being in-

J. M. Farley Nuclear Plant - Unit Nos. 1 & 2 Steam Generator Tube Experience as refere ed in NUREG-0886 April 12, 1982 Page 3 stalled in the steam generators". This statement is incorrect. The hacksaw blade was dropped during the steam generator moisture carryover modification, which was performed during con-struction. Furthermore, the hacksaw blade was located and removed in February,1980.

Two tubes were nicked during the installation of upper inspection ports in the same steam gen-erator. To prevent future problems, these two tubes were plugged and the upper U-bend portions of the tubes were removed. As previously mentioned in paragraph 1.b., this corrective action was taken during construction; therefore these tubes never leaked.

If you have any questions, please advise.

Yours truly, hk V (/ h - ii F.L.21ayton,/Jr.

U l STB:bs cc: Mr. R. A. Thomas I Mr. G. F. Trowbridge Mr. J. P. O'Reilly Mr. E. A. Reeves

, Mr. W. H. Bradford l

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