ML19260D281
| ML19260D281 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 01/16/1980 |
| From: | Rooney V Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8002080255 | |
| Download: ML19260D281 (5) | |
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?r 3,,(. 8 January 16, 1980 Docktt No. 50-271 LICENSEE: Yankee Atomic Electric Company FACILITY: Vermont Yankee Nuclear Power Corporation MEETING HELD ON DECEMBER 11, 1979 TO DISCUSS VY FUEL HISTORY AND WATER R00 WEAR On December 11, 1979 representatives of Vermont Yankee Nuclear Power Corporation, Yankee Atomic Electric Company, and General Electric Company met with the NRC staff in Bethesda, Maryland. Attachment A lists attendees.
There was a discussion of the operational history of Vermont Yankee fuel including recent hot lab examination results. The information discussed is contained in a proprietary letter from J. Charnley of General Electric to F. Coffman of the NRC dated December 11, 1979. General Electric was requested to provide a nonproprietary version of this letter.
The water rod lower end plug wear observed on Vermont Yankee fuel assemblies was also discussed. The Division of Operating Reactors has prepared a draft information notice for use by the Division of Inspection and Enforce-ment. This draft information notice, which suninarizes the discussions at the meeting of December 11, is included as Attachment B.
lj' Vernon L. Rooney, Project Manager Operating Reactors Branch #3 Division of Operating Reactors
Enclosures:
As stated 1938 188 f
800gogn 2W
Yankee Atomic Electric Company I
e cc:
Ms. J. M. Abbey John R. Stanton, Director Vemont Yankee Nuclear Power Radiation Control Agency j
Corporation Hazen Drive 77 Grove Street Concord, New Hampshire 03301 Rutland, Vemont 05701 John W. Stevens Mr. Donald E. Vandenburgh, Conservation Society of Vice President Southern Vermont Vemont Yankee Nuclear Power P. O. Box 256 Corporation Townshend, Vermont 05353 Turnpike Road, Route 9 Westboro, Massachusetts 01581 Dr. Mars Longley, Director Occupational & dadiological Health John A. Ritsher, Esouire 10 Baldwin Street Ropes & Gray Montpelier, Vermont 05602 225 Franklin Street Boston, Massachusetts 02110 New England Coalition on Nuclear Pollution Laurie Burt Hill and Dale Farm Assistant Attorney, Genera' West Hill - Faraway Road Environmental Protection Division Putney, Vemont 05346 Attorney General's Office One Ashburton Place, 19th Floor Public Service Board Boston Massachusetts 02108 State of Vemont 120 State Street Richard E. Ayres, Esauire Montpelier, Vement 05602 Natural Resources Defense Counsel 917 15th Street, N. W.
W. F. Conway, Plant Superintendent Washington, D. C.
20005 Vemont Yankee Nuclear Power Corporation Honorable M. Jerome Diamond P. O. Box 157 Attorney General Vernon, Vemont 05354 State of Vemont 109 State Street Mr. Charles Sheketoff Pavilion Office Building Assistant Director Montpelier, Vemont 05602 Vemont Public Interest Research Group, Inc.
Anthony Z. Roisman 26 State Street Natural Resources Defense Council Montpelier, Vemont 05602 917 15th Street, N. W.
Washington, D. C.
20005 Brooks Memorial Library 224 Main Street Mr. J. E. Griffin, President Brattleboro, Vemont 05301 Vermont Yankee Nuclear Power Corporation Mr. Robert L. Smith i
77 Grove Street Licensing Engineer i
Rutland, Vemont 05701 I
Vermont Yankee Nuclear Power Corporation 25 Research Drive
/
Westborough, MA 01581 1938 189
Attachment A LIST OF ATTENDEES GENERAL ELECTRIC R. English C. Richards R. Engel W. Tamai J. Charnley VT. YANKEE NUCLEAR POWER CORP.
S. Jefferson YANKEE ATOMIC ELECTRIC COMPANY R. Smith NRC C. DeBevec B. Raymond D. Bessette M. Mendonca R. Riggs V. Rooney E
1938 190
ATTACHMENT Recomendations by DOR on Infomation Notice for 8x8R Water Rad Lower End Plug Wear On October 3,1979, Vemont Yankee Nuclear Power Corporation reported (LER-79-25/IP) observance of lower end plug wear on the water rods of 8x8R demonstration fuel assenblies. These observations were obtained during re-fueling outage inspections. Subsequent to the initial LER, the Licensee issued LER 79-25/IT on October 17, 1979. LER 79-25/IT provided more detailed descriptions of the probable cause and corrective action associated with this event.
The lower end plug wear was isolated to the water rods of the 8x8R fuel as semblies. The cause of the wear was attributed to flow excitation of the water rods by coolant cross flow within the lower tie plate flow volume The repetitive contact of the Zircaloy lower end plug with the stainless steel lower tie plate resulted in preferential wear of the softer Zircaloy end plug. No significant wear was observed in the lower tie plate.
To provide in-reactor experience on the modification proposed to mitigate lower end plug wear, the Licensee will include fourmodified 8x8R fuel bundles in their upcoming cycle of operations. The primary modification consists of using two capture water rods with shorter lower end plugs to eliminate the flow-induced excitation. Two of these fuel assenblies were previously irradiated. Vermont Yankee Nuclear Power Corporation plans to perfonn sur-veillance on these four modified bundles at the next refueling outage.
The surveillance will confim the efficacy of the modifications and the currently estimated rate of wear.
Based on evaluation of the lower end plug wear rates, and the absence of any indicated rotational movement of the water rods with worn lower end plugs, GE and the Licensee have concluded that no additional corrective action is warranted at this time.
To support this conclusion, on December 11, 1979, the Licensee and General Electric Company (GE) presented detailed status of their evaluations and analyses of this condition to the NRC staff. As a result of the infomation provided in the December 11, 1979 meeting, the staff agreed with the conclusion that no additional corrective action is warranted at this time.
The staff requested that GE document and fomally submit proprietary, and non-proprietary versions of their evaluations and analysis. In addition, the staff requested the Licensee to submit a supplement to the earlier LER's considering the potential for loose parts.
To provide additional confimatory evidence supporting the findings by GE and the Licensee, GE will develop a surveillance program specifically addressed at inspections for wear of the lower end plugs. When this program is developed, GE will propose the program to the NRC staff. BWR Licensees are encouraged to support a GE surveillance program.
1938 191
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