ML20054B981
| ML20054B981 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 04/01/1982 |
| From: | Wigginton D Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20054B982 | List: |
| References | |
| NUDOCS 8204190346 | |
| Download: ML20054B981 (5) | |
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- R 01 1962 Docket No. 50-295 d2C1tGD P
LICENSEE: Commonwealth Edison Company t-APR1-41982n 30 ssa:m rumsm FACILITY: Zion Station Unit No. 1 c,
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SU3 JECT:
MEETING
SUMMARY
- STEAM GENERATOR RECOVERY PROGRAM g
4 The licensee and Westinghouse met with the staff on March 25, 1982 to discuss the recovery program of the damaged ID steam generator and the U-bend cracking problem in all the steam generators. An attendance list is attached as Enclosure 1.
The licensee's presentation was made from the information included in Enclosure 2
Photos were taken at 1, 21/2, and 5 power and gave high resolution of the tube ends, tube sheet, and welds. The radiation levels at the tube sheet is 24 R per hour which is causing some problem with the in3pection and repair.
The residence time in the steam generator is 2 to 4 minutes before receiving the quarterly dose limit, therefore,'about 70 people were involved in the inspection and about 100 will be required for the repair.
The tube repair will consist of straightening the tube ends and re-rolling the tube to tube sheet joint. The original rolling was performed at 80 inch ponds and the repair will be done at 120 inch ponds. The repair will allow eddy current test probes to be inserted from the hot side and plugs if eventually required. The tube to tube sheet weld is the structural joint of record. The rolled joint is capable of being the structural member but no credit is taken by Westinghouse or Zion for the rolled joint. Either the weld or rolled joint is code allowable.
f The rolling operation.111 be automatic using an indexing and rolling machine developed by Westinghouse. The rolling is not expected to exceed the allowable thinning of the tube wall or usage factors. This information is covered more thoroughly in Enclosure 3 to this report.
The repair program will consist of required manual repairs, the automatic rolling process, and a minimal manual process if the auto-equipment fatis.
Some 200 of the outer rows will be left as is since the ECT can be done easily from the cold side. The three roller process was chosen to give greater i
control and the most effective use of the jumpers.
l The final inspection will also include high resolution photographs. The staff's concern is that the inspection of record is penetrant testing (PT) and Zion does not propose to repeat this following the repairs. The radiation levels must be considered in any decision to repeat some PT's.
8204190346 820401 PDR ADOCK 05000295 P
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. The licensee has completed the ECT of A, B, and C steam generators and has decided to plug row one tubes after determining that the U-bend cracking problem exists in the Zion steam generators. Zion performed a helium leak test of their steam generators and the results helped to correlate leaks with ECT results. A problem has surfaced at Zion with tubes close to anti-vibration bars (AVB). At least one tube experienced an 80% thru wall indi-cation in one cycle while another tube with 38% at the beginning of the cycle did not experience any further deterioration. Zion will plug any tube with AVB indication over 20% although the plugging limit is 40%. The Zion position is that the availability during the next cycle is assured by plugging the row one tubes, there have been no indications of unacceptable leakage in row two during a single cycle therefore it is best to leave unplugged and gain more experience, and there have been no leaks yet due to AVB problems but Zion will continue to watch. The plugging planned will not effect the LOCA analysis which assumes up to 7% plugged or the thermal degrading which can go up to 14% of the tubes.
The staff's position which was provided to the licensee consisted of three pa rts.
- 1) The licensee will be given approval to continue with the repair program with the understanding that further approval is required for the final inspection. The staff believes some PT is required to reestablish the inspection of record.
- 2) The licenses should submit the results of all the ECT, an evaluation of l
the results, and a basis for assuring the plant can operate in future l
cycles with tube integrity Gjven the U-bend and AVB problems, t
- 3) The effort started earlier with Zion to change their Technical Specif1-cations conditions of primary iodine activity to include the more restrictive of the current or Westinghouse Standard Technical Specifi-cations should be accelerated. This activity level is determined by l
analysis should a tube rupture during operation.
DRIGINAL SIGNED David Wigginton, Project Manager i
Operating Reactors Branch #1 l
Division of Licensing l
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MEETING
SUMMARY
OPERATING REACTORS BRANCH NO. 1 DIVISION OF LICENSING Docket File NRC PDR Local PDR ORB 1 File J. He'temes, AEOD B. Grin,es S. Varga Project Manager OELD OI&E (1)
ACRS (10)
NRC Participants NSIC cc: Licensee with Service List i
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Mr. Louis 0. De1 George Commonwealth Edison Company cc: Robert J. Vollen, Esquire 109 North Dearborn Street Chicago, Illinois 60602 Dr. Cecil Lue-Hing
' Director of Research and Development Metropolitan Sanitary District of Greater Chicago 100 East Erie Street Chicago, Illinois 60611 Zion-Benton Public Library District 2600 Emmaus Avenue Zion, Illinois 60099 Mr. Phillip P. Steptoe Isham, Lincoln and Beale Counselors at Law One First National Plaza 42nd Floor Chicago, Illinois 60603 Susan N. Sekuler, Esquire Assistant Attorney General Environmental Control Division 188 West Randolph Street, Suite 2315 Chicago, Illinois 60601 U. S. Nuclear Regulatory Commission Resident Inspectors Office 105 Shiloh Blvd.
Zion, Illinois 60099 James P. Xeppler Regional Administrator - Region III U. S. Nuclear Regulatory Commission l
799 Roosevelt Road l
Glen Ellyn, Illinois 60137 1
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ZION STEAM GENERATOR MEETING 3/25/82 BETHESDA, MD.
NAME ORGANIZATION D. Wigginton NRR/ ORB #1 W. J. Key NRC RIII Earl J. Brown NRC/AEOD C.Y. Cheng NRC/MTEB K.R. Wichman NRC/DL/0RAB Emmett Murphy NRC/DE/MTEB
- Phil Mathews NRC/DE/CMEB Oran Bertsch W Tampa Hal Keller W WSD John N. Esposito
_ Nuc. Tech. Div.
W A. W. Klein W NTD Robert E. Shannon Commonwealth Edison Joe Reiss Ceco - SNED Frank G. Lentine CECO - Nuclear Licensing Wayne L. Stiede Ceco Asst. VP Nuclear Operations L. D. (. Dell Butterfield CECO - Sta Nuc. Eng. Dept.
Lynn Connor Doc Search Associates /NSAC Gus Lainas NRC/DL T. A. Ippolito NRC/DL
- Part Time h
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