ML082700569
| ML082700569 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 09/25/2008 |
| From: | Collins S Region 1 Administrator |
| To: | O'Brien D State of VT, Dept of Public Service |
| Barkley R, RGN-1/DRP/PB7, 610-337-5065 | |
| Shared Package | |
| ML082700566 | List: |
| References | |
| Download: ML082700569 (3) | |
Text
September 25, 2008 David OBrien, Commissioner Vermont Department of Public Service 112 State Street, Drawer 20 Montpelier, VT 05620-2601
Dear Commissioner OBrien:
I am responding to your letter to me, dated September 19, 2008, in which you expressed concern with the recent leak in Vermont Yankees east, non-safety related, cooling tower. On September 16, 2008, Entergy identified a leak from a slip joint in the distribution header in Cell 1-3 caused by the loss of some packing material. While addressing the leak, Entergy identified degradation, such as cracks and bending, in six wooden support columns internal to the cooling tower. Entergy evaluated the degradation and replaced the columns, as necessary.
In July 2008, Entergy identified a leak in the east cooling tower that occurred when the supply header, which carries the water, sagged after the underlying horizontal support beam broke.
That leak was the result of structural damage, which could have had a generic implication for the safety-related cooling tower cell 2-1, or the seismic cell 2-2 in the west cooling tower. An NRC Special Inspection Team (SIT) is evaluating the licensees conclusion that the issue did not affect the safety-related or seismic cells, and is evaluating the adequacy of the licensees corrective actions from the August 2007 event, for assurance that the safety-related tower cell is adequately inspected and maintained.
We understand the Department of Public Services interest in the maintenance and reliability of Vermont Yankee, and that the State is evaluating the cooling tower issues as part of its Comprehensive Reliability Assessment. The NRC is independently reviewing this most recent leak associated with the non-safety portions of the cooling tower to ensure it does not have any applicability to the safety-related or seismic cells, nor reflect on licensee performance in maintaining plant equipment in the non-nuclear portions of the plant. We are evaluating encompassing the conclusions and findings of our review of the most recent issues with the east cooling tower in the ongoing special inspection.
The NRC monitors the issues experienced with the non-safety portions of the cooling towers as these issues result in unplanned plant downpowers with little warning. One of the performance indicators monitored by the NRC is unplanned power changes greater than 20% per 7,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> of plant operation. If this performance indicator is exceeded due to downpowers caused by problems experienced by the cooling towers, additional NRC inspection of the facility will be required. This performance indicator is currently in the green band through the 2nd quarter of 2008; the performance indicator for the current quarter will be calculated and published late next month. Information on the current status of this performance indicator is enclosed.
Commissioner OBrien 2
Given the level of stakeholder interest in Vermont Yankee, we are evaluating the best way to inform public officials and members of the public regarding this matter. We will promptly keep you informed of other planned discussions regarding Vermont Yankee.
Should you have any further questions in this matter, please contact Marjorie McLaughlin of my staff at (610) 337-5240.
Sincerely,
/RA/
Samuel J. Collins Regional Administrator
Enclosure:
Unplanned Power Change Performance Indicator for Vermont Yankee
Commissioner OBrien 2
Given the level of stakeholder interest in Vermont Yankee, we are evaluating the best way to inform public officials and members of the public regarding this matter. We will promptly keep you informed of other planned discussions regarding Vermont Yankee.
Should you have any further questions in this matter, please contact Marjorie McLaughlin of my staff at (610) 337-5240.
Sincerely,
/RA/
Samuel J. Collins Regional Administrator
Enclosure:
Unplanned Power Change Performance Indicator for Vermont Yankee SUNSI Review Complete: RSB1 (Reviewers Initials)
DOCUMENT NAME: G:\\ORA\\BARKLEY\\O'Brien Letter September 2008.doc After declaring this document An Official Agency Record it will be released to the Public.
To receive a copy of this document, indicate in the box: "C" = Copy without attachment/enclosure "E" = Copy with attachment/enclosure "N" = No copy ML082700566 (Adams Pkg) ML082700569 (Adams Letter) ML082700823 (Adams Encl)
OFFICE RI/ORA RI/DRP RI/SLO RI/ORA NAME RBarkley DLew M McLaughlin SCollins DATE 09/25/08 09/25/08 09/25/08 09/25/08 OFFICIAL RECORD COPY