ML18029A526
| ML18029A526 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 05/03/1985 |
| From: | Domer J TENNESSEE VALLEY AUTHORITY |
| To: | Vassallo D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8505090311 | |
| Download: ML18029A526 (11) | |
Text
REGULATORY ORMATION DISTRIBUTION SYS M,(RIDS)
ACCESSION NBR;8505090311 DOC ~ DATE: 85/05/03 NOTARIZED; YES DOCKET FACIL:50"259 Browns Ferry Nuclear Power Stations Unit 1~
Tennessee 05000259 AUTH BYNAME AUTHOR AFFILIATION DOMERgJ, ~ A, Tennessee Valley Authority RECIP ~ NAME RECIPIENT AFFILIATION VSSALLO,D,BE Operating Reactors Branch 2
SUBJECT:
Forwrds plans for piping insps~corrective actions 8/or mods, per S31219 order conf,irming util commitments on pipe rack-related issues 8
DE McCloud 850327 ltd DISTRIBUTION CODE:
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OR Submi ttal: General Distribution NOTES:NMSS/FCAF
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1
TENNESSEE VALLEYAUTHORITY CHATTANOOGA, TENNESSEE 3V401 400 Chestnut Street Tower II May 3, 1985 Director of Nuclear Reactor Regulation Attention:
Mr. Domenic B. Vassallo, Chief Operating Reactor Branch No.
2 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C.
20555
Dear Mr. Vassallo:
In the Matter of the Tennessee Valley Authority Docket Nos. 50-259 50-260 50-296 By your letter to H. G. Parris dated December 19,
- 1983, we received an Order confirming TVA commitments on pipe crack related issues for the Br owns Ferry Nuclear Plant unit 1.
That Order required submittal of plans for inspections, corrective actions, and/or modifications of recirculation and/or other reactor coolant pressure boundary piping systemsduring the next refueling outage.
Enclosed are those plans.
The Order required that those plans be submitted at least one'onth before the start of the next refueling outage (cycle 6)'.
As explained in TVA's letter from D. E. McCloud to H. R. Denton dated March 27, 1985, it was decided to keep unit 1
in shutdown until all environmental qualification work required by -10 CFR 50.49 is complete.
This being an early unanticipated shutdown of unit 1, submittal of these plans was projected for early May 1985.
This was discussed with the NRC Browns Ferry Project Manager, R. J. Clark.
If you have any questions, please get in touch with us through the Browns Ferry Project Manager.
Very truly yours, r
Subscribed,ayd sworn to efore me this 8~
day of TENNESSE VALLEY AUTHORITY J.
A. Domer Nuclear Engineer 1985.
Notary Public My Commission Expires Enclosure cc:
See page 2
85050903ii 850503 PDR ADOCK 05000259 i,
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An Equal Opportunity Employer
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Director of Nuclear Reactor Regulation May 3, 1985 cc (Enclosure):
U.S. Nuclear Regulatory Commission Region II ATTN:
Dr. J. Nelson Grace, Regional Administrator 101 Marietta Street;,
NW, Suite 2900 Atlanta, Georgia 30323 Mr. R. J. Clark Browns Ferry Prospect Manager U.S. Nuclear Regulatory Commission 7920 Norfolk Avenue
- Bethesda, Maryland 20814
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Browns Ferry Nuclear Plant Unit 1, Cycle 6 Outage, Plans for Piping Inspections, Corrective Actions, and/or Modifications
SUMMARY
TVA plans.a 100-percent inspection of welds susceptible to IGSCC and further described below.
Following these inspections, structural integrity will be demonstrated analytically or by analysis and corrective action on welds containing indications of cracking.
Welds previously repaired by the weld overlay method have been demonstrated by analysis to be adequate for an additional cycle of operation..
Modification and corrective action for mitigation of IGSCC is being considered by TVA for the purpose of optimizing durations of the cycle 6 and cycle 7 outages.
Figure 1 is a diagram of the cycle 6 logic for the subject activit'ies.
DISCUSSION Examinations TVA will ultrasonically examine all accessible stainless and dissimilar welds greater than or equal to 4 inches in the recirculation, residual heat
- removal, core spray, and reactor water cleanup systems.
Welds with design access limitations which prevent an ultrasonic examination that meets the IGSCC UT procedure will be sur face examined unless the weld is totally inaccessible.
The inaccessible welds are:
~Astern RHR RHR Core Spray Core Spray RWCU Weld ID Flued Head-Pipe Flued Head-Pipe Flued Head-Pipe Flued Head-Pipe Flued Head-Pipe Location Penetration X-13A Penetration X-13B Penetration X-16A Penetration X-16B Penetr ation X-14
~Drawin CE0-2070-C CHM-2070-C CHM-2071-C CHM-2071-C CHM-2073-C The 43 overlayed welds on unit 1 will be examined using our existing ultrasonic procedures and techniques.
TVA is investigating employing some advanced nondestructive examination techniques to increase our capability in this area.
~Anal sls TVA has in hand and is reviewing analyses of 43 welds overlayed during the cycle 5 outage.
These analyses demonstrate structural integrity against limit load collapse and adequate fracture toughness against unstable fracture for two cycles of operation (cycles 6 and 7).
Nine welds containing indications of'racking were returned to service in the "as is" condition by analytical justification.
These welds will be dispositioned following the cycle 6 inspection as appropriate to ensure structural integrity.
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