ML20153D700
| ML20153D700 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 08/29/1988 |
| From: | Hairston W ALABAMA POWER CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML17201Q496 | List: |
| References | |
| IEB-88-002, IEB-88-2, NUDOCS 8809060016 | |
| Download: ML20153D700 (3) | |
Text
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,[ I Alathna Power Cornpany a
600 North 18th Stree' Post Offce Box 2641 Birmingham. Alabama 352914400 Telephone 205 250-1837 W. G. Hairston,Ill Senior Vice President AlabamaPower August 29, 1988 Docket Nos. 50-348 50-364 P
U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Vashington, DC 20555 Gerstlemen t l
J. M. Farley Nuclear Plant - Units 1 and 2 Rapidly Propagating Fatigue Cracks in Steam Generator Tubes - NRC Bulletin No. 88-02 By letter dated March 23, 1988, Alabama Power Company submitted a written report detailing the status of its compliance with the provisions of NRC Bulletin No. 88-02.
Since results oc reviews of eddy current data for evidence of denting at top support plate intersections vere not available at that time, Alabama Power Company implemented a I
program for enhanced primary to secondary leak rate monitoring.
A copy of the program was enclosed with the written report.
The March 23, 1988 letter also discussed Alabama Pover Company's l
alternate approach to address the denting reviev and flov analysis l
issues.
Using that approach, Vestinghouse, the steam generator supplier, specified potentially susceptible tubes, which vere then r
reviewed for evidence of denting, as defined in the bulletin. This reviev was performed on an expedited basis that vould allow for corrective actions to be taken during the refueling outage, which was upcoming for Unit 1 at that time. The preliminary results of that expedited review revcaled that no corrective actions vere necessary for Unit I steam generators.
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- 0 gg Vestinghinuse has nov completed the review for denting on tubes in both b
Farley units determined to be potentially susceptible and has concluded
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that: "Essentially all tubes were found to have top tube support plate l
8 corrosion plus magnetite in the crevice which corresponds to the NRC
.og definition of "denting" in NRC Bulletin No. 88-02.
None of the tubes in ag Farley 1 vere found to have deformation due to denting.
Some of the t
'o tubes in Farley 2... have possible, but questionable, tube
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deformation." Listings of the tubes which were evaluated and those with os questionable deformation are provided in the enclosed analysis report.
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U. S. Nuclear Regulatory Commission August 29, 1988 Page 2
'lhere denting was found, the bulletin requested an analysis be conducted with an assessment of stability ratios (including flow peaking effects) for the most limiting tube locations to assess the potential for rapidly propagating fatigue cracks. The stability ratios derived from the analysis should be directly comparable to that for the tu';e which ruptured at North Anna. The analysis should also assess the depth of penetration of each antivibration bar (AVB). The bulletin also requested that a detailed description of the analysis and its results be submitted for NRC Staff review and approval prior to the next 2cheduled restart from a refueling outage.
Vestinghouse has completed the anal"sis requested by the bulletin and determined there are no potentially susceptible tubes in either Farley unit and: "No tubes require corrective action to minimize the likelihood of a fatigue induced tube rupture even if tube denting deformation should occur in the future."
The Vestinghouse analysis report is hereby submitted for NRC Staff approval.
Provided as an Enclosure to this report are three proprietary copies of the Joseph H. Farley Units 1 and 2 Evaluation for Tube Vibration Induced Fatigue report (VCAP-11875) and a non-proprietary version of the same report (VCAP-11876).
In accordance with 10CFR2.790, Alabama Power Company is requesting that the proprietary version of the enclosed report (VCAP-11875) be withheld in whole from public disclosure.
Provided vitL the Enclosure to this letter is an affidavit executed by Mr. R. A. Viesemann, Manager, Regulatory and Legislative Affairs for Vestinghouse Corporation. This affidavit contains the information discussed in 10CFR2.790.b.4.
The next refueling outage (Unit 2 sixth) is scheduled to start Harch 24, 1989; therefore, NRC Staff approval is requested by February 10, 1989.
This analysis assesses both Parley units and approval c' the analysis report vill be considered to apply to both units.
Alabama Power Company enclosed a copy of the program for enhanced monitoring of primary to secondary leakage with the March 23, 1988 report. This program omitted the allovance of grace for the frequency of various analyses.
Alabama Pover Company hereby revises that program to shov a grace period of 2 25 percent applicable to each analysis included in the program. This program for enhanced monitoring of primary to secondary leakage vill be terminated when NRC approval of the enclosed analysis is received.
Alabama Power Company also committed in the report to performing, at a future date, a reviev, on a sampling basis, of top support plate intersections to determine the extent of any evidence of denting vhich may be present. As the Vestinghouse review has determined that virtually all intersections evaluated had evidence of corrosion plus magnetite in the crevice, there is no need to evaluate the other tubes for evidence of denting. Alabama Pover Company hereby withdravs that commitment.
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e U. S. Nuclear R0dulatory Commission August 29, 1988 Page 3
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In summary, the enclosed analysis report concludes that, although evidence of denting was found, there are no tubes in either Farley unit potentirlly susceptible to the rapidly propagating fatigue cracking mechanist identified at North Anna.
The enclosed report is considered to be proprietary and an application for withholding from public disclosure is enclosed also.
If there are any questions, please advise.
Respectfully submitted, ALABAMA POVER COMPANY j
W.).lWW V. G. Hairston, III VGH,III/RSF: dst-\\i t
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Enclosure cci Mr. L. B. Long SVORN TO AND SUBSCRIBED BEFORE ME j
Dr. J. N. Grace
/Ek,1988 Mr. E. A. Reever.
THI )
DAY 0 Mr. V. H. Bradford iotaryPq)c My Commission Expires ff'$2 f"fdk i
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