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Vermont Yankee Nuclear Power Plant
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Vermont Yankee is a General Electric boiling water reactor (BWR) type nuclear power plant currently owned by Entergy Nuclear. It is located in the town of Vernon, Vermont and generates 620 megawatts (MWe) of electricity. The plant began commercial operations in 1972. It provides Vermont with nearly three fourths (73%) of its electrical generating capacity
prior to the 2006 uprate and meets 35% of the overall energy requirements of the state.
The nuclear plant uses the adjacent Connecticut River for condenser cooling water.
company employs 600 people at this location.
Working with the regulatory agencies, the company has compiled $100 million for possible decommissioning.
In 2002, the company signed a 10-year agreement with the state to provide one-third of Vermont's electrical requirements at about 5 cents per kilowatt-hour.
uly 31, 2002, Entergy Nuclear Vermont Yankee, LLC (ENVY) purchased Vermont Yankee from Vermont Yankee Nuclear Power Corporation for $180 million.
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Encyclopedia
Vermont Yankee is a General Electric boiling water reactor (BWR) type nuclear power plant currently owned by Entergy Nuclear. It is located in the town of Vernon, Vermont and generates 620 megawatts (MWe) of electricity. The plant began commercial operations in 1972. It provides Vermont with nearly three fourths (73%) of its electrical generating capacity
prior to the 2006 uprate and meets 35% of the overall energy requirements of the state.
The nuclear plant uses the adjacent Connecticut River for condenser cooling water.
Operations
The company employs 600 people at this location.
Working with the regulatory agencies, the company has compiled $100 million for possible decommissioning.
In 2002, the company signed a 10-year agreement with the state to provide one-third of Vermont's electrical requirements at about 5 cents per kilowatt-hour.
Ownership and Operational License
On July 31, 2002, Entergy Nuclear Vermont Yankee, LLC (ENVY) purchased Vermont Yankee from Vermont Yankee Nuclear Power Corporation for $180 million. Entergy received the reactor complex, nuclear fuel, inventories, and related real estate. The liability to decommission the plant, as well as related decommissioning trust funds of approximately $310 million, was also transferred to Entergy. The acquisition included a 10-year power purchase agreement (PPA) under which three of the former owners will buy a portion of the electricity produced by the reactor, which is longer than term remaining for the current operating license for the plant, which expires on March 21, 2012.
In 1978, the Vermont Yankee reactor was the subject of Vermont Yankee Nuclear Power Corp. v. Natural Resources Defense Council, Inc., an important United States Supreme Court administrative law case which ruled that courts cannot impose procedures upon the NRC as this exceeds their power of judicial review.
As a result of an NRC approved Extended Power Uprate (EPU), Vermont Yankee achieved its new rated power of 1912 MWth (120% of its original licensed thermal power of 1593 MWth) on May 6, 2006. The power increase was delayed at several plateaus to take data on the reactor's steam dryer in accordance with the NRC imposed power ascension test plan.
Dry Cask Storage
Due to delays opening Yucca Mountain spent nuclear fuel repository by the federal government for long term storage of spent nuclear fuel, Vermont Yankee's spent fuel pool contents are nearing capacity. Entergy Nuclear has gained approval for enough dry cask storage to allow continued operation beyond the existing reactor operating license expiry date in 2012. Loading spent fuel into transportable dry fuel storage casks is also a step toward sending it to the central federal repository when it opens. Most of the spent fuel will continue to be stored underwater in the spent fuel pool.
ENVY began its first dry cask storage campaign in May, 2008. The first fully loaded cask was inadvertently lowered to the refueling floor from a height of about , after successfully being raised from the spent fuel pool. The failure is attributed to a breaking relay in the rated overhead crane. The crane was last tested for any weight greater than 70% of the total fully loaded cask in 1975. In August, 2008, Vermont Yankee successfully completed the first dry storage campaign with the transfer of the fifth cask from the reactor building to the storage pad, each loaded with 68 spent fuel assemblies. The casks are moved from the reactor building to a storage pad located above the 500 year flood plain of the Connecticut River using a large specially designed cask moving machine.
Closure/Extension Planning
Entergy Nuclear Vermont Yankee applied to the Nuclear Regulatory Commission for a license extension of 20 years on 27 January, 2006. A decision on this extension is likely in 2009.
Cooling Tower Collapse
On August 22 2007, the fourth cell of Vermont Yankee's three story west cooling tower collapsed. A large amount of cooling water flowed out of the tower's damaged pipe line following the collapse until operators were able to isolate the tower. The spilled water was collected in the same concrete basin below the towers that is used when the towers are functioning properly. Operators immediately reduced reactor power to 30% capacity following the event.
The spilled cooling water was part of the non-radioactive circulating water system which draws from the Connecticut River. The collapse was an industrial safety event and did not threaten the integrity of the reactor or release any radiation into the environment. The plant's primary source of condenser cooling water is the river itself. The cooling towers are used to further cool the condenser cooling water at times when the river is not cold enough to absorb the plant's rejected heat and meet the environmental discharge permit. The NRC has stated that the remaining cooling tower is enough to allow the plant to return to full capacity at any time, however up until September 16, 2007 the reactor operated at 50% power.
The cause of the collapse was found to be corrosion / rotting of lumber due to carbon steel bolts. Also dry rot was found in some beams. A beam failed and caused the cell to sag which caused the main pipe to begin leaking water. This water collected and the extreme extra weight from this large amount of extra water caused other beams to fail. Entergy admitted that although the inspection process was superior to the recommendations made by the cooling tower design/construction company it was inadequate. The remote robotic cameras being used to perform inspections were not able to reach the areas where the rot was the most prevalent. Because of this failure both towers had complete inspections performed based on the information learned from the failure. Entergy has asserted that future inspections will be much more stringent in order to guarantee no further problems in the future.
Controversy
The partial collapse of the cooling tower and a reactor scram in 2007 have each been traced to shortcomings in the maintenance of equipment, and both have raised questions about the reliability of the power station
In March 2008 the Governor stated that, before the State of Vermont is in a position to consider a license extension for Vermont Yankee, a comprehensive reliability and safety assessment of the power station should be conducted.
Also in March 2008, a state Senate committee advised that it wanted the Legislature to appoint a panel that would oversee an independent review of the Vermont Yankee nuclear power plant. Entergy Nuclear, which owns the plant, has said the review is unnecessary.
Anti-nuclear groups have said that the proposal doesn't go far enough. There have been protests in relation to continued operation of the plant.
Official inspection
The Nuclear Regulatory Commission performed a tri-annual inspection July-August 2008. It found three "minor faults." An Associated Press report said that it had won "high marks." An anti-nuclear spokesman expressed dissatisfaction with the inspection.
Plans for dismantling
The plant's owner plans to dismantle it in 2067 regardless of the decision on the 20-year relicensing in 2012. The expected cost then would be $875 million.
See also
- Nuclear power in the United States
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