ML19317F205
| ML19317F205 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 05/06/1976 |
| From: | Zech G Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8001080920 | |
| Download: ML19317F205 (4) | |
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,m UNITED STATES j
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WASHINGTON, D. C. 20566 e
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DOCKET No.:
50-287 DATE:
May 6, 1976 LICENSEE:
Duke Power Company (DPC)
FACILITY:
Oconee Unit 3 SU4fARY OF MEETING HELD ON APRIL 14, 1976, TO DISCUSS ' DIE RESULTS OF AN INSPECTION OF 'niE REACTOR SURVEILLANCE CAPSULE HOLDER TUBES AT OCONEE UNIT 3 AND THE PROPOSED PLANS FOR OPERATION FOR THE REMAINDER OF CYCLE 1 On April 14, 1976, representativu of Babcock & Wilcox (BGW) and DPC met with the NRC staff to evaluate the extent of damage to the reactor vessel surveillance capsule holder tubes and to determine whether the holder tubes can remain in the Unit 3 reactor vessel for the remainder of Cycle 1 operation.
A list of attendees is enclosed.
Significant discussions / agreements are summarized below.
B6W provided a detailed account of the holi "abe inspection. The locations of internal wear damage were shom and the probable cause identified as flow-induced relative motion between the holder tubes and push rod assemblies within the tubes. On two of the three holder tubes a complete severance of the holder tubes had occurred at the axial location of the second push rod spacer from the top.
In addition, external visual inspections and ultrasonic testing revealed evidence of wear at the journal bearing area located at the bottom of the outer shroud tube. The journal bearing wear had caused the bearing clearance to increase. To restore proper journal bearing support, the licensee rolled out each ho1A r tube in the journal bearing area.
Some spring-back was observed, but net to a significant degree.
The actual stress loadings on the holder tubes (measured during Hot Functional Testing) were shown to be below allowance limits.
In addition, the results of a fatigue evaluation were shown which took into consideration the material condition of the holder tubes.
The staff agreed that the results of the fatigue evaluation showed that, with the loads normally expected, sufficient material integrity remained in the holder tubes to give reasonable assurance that any further degrada-tion would not occur. Of concern, however, was positive identification of the actual wear meahanism. The wear observed at the journal bearing locations indicates that the relative motion between the holder tubes and 8001080 9 g g
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,m 2-May 6, 1976 push rod assemblies may not be the only source of wear. Considering this, further review would be necessary before a decision could be made to allow the holder tubes to remain in the core for the remainder of Cycle 1 operation.
Gary G. Zech, Project Manager Operating Reactors Branch #1 Division of Operating Reactors
Enclosure:
List of Attendees cc: See next page l
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j NRC STAFF MEETING WITH CUKE POWER COMPANY AND BABCOCK & WILCOX April 14, 1976 NRC V. S. Noonan W. J. Ross P. N. Randell 4
J. Strosnider l
G. G. Zech DPC M. S. Tuckman D. C. Holt B8W W. J. Keyworth L. Behn L. A. Creasey C. Pryor
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Meeting Summary for Duke Power May 6, 1976 cc:
Licensee B'. Grimes NRC PDR G. Knighton
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Local PDR B. Youngblood B. Rusche W. Regan E. Case D. Bunch R. Boyd J. Collins R. Heineman W. Kreger V. Stello R. Ballard H. Denton M. Spangler D. Skovholt J. Stepp R. Denise L. Hulman R. DeYoung T. Carter R. Maccary OR PM D. Ross S. Sheppard R. Tedesco R. Fraley, ACRS(16)
K. Goller OISE(3)
D. Eisenhut OELD V. Moore Principal Staff Participants R. Vollmer M. Ernst bec:
T. B. Abernathy, TIC W. Gammill J. R. Buchanan, NSIC P. Collins C. Heltemes R. Houston T. Speis R. Clark l
J. Stol:
K. Kniel O. Parr W. Butler D. Vassallo J. Knight S. Pawlicki I. Sihweil,
P. Check T. Novak Z. Ros: toc:y V. Benaroya G. Lainas T. Ippolito D. Ziemann G. Lear R. Reid L. Shao R. Baer A. Schwencer
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