Vermont Yankee Nuclear Power Plant

Vermont Yankee Nuclear Power Plant
Company type	Nuclear power plant
Industry	Energy
Founded	January 1, 1972; 54 years ago in Vernon, Vermont, United States
Defunct	December 29, 2014
Fate	Shutdown and decommissioned
Headquarters	Brattleboro, Vermont, United States
Area served	Vermont, United States
Products	Electricity generation (nuclear power)
Owner	Entergy Nuclear Vermont Yankee, LLC (since 2002)
Number of employees	600 (2008)

Vermont Yankee was a nuclear generating station located in Vernon, Vermont, operating a boiling water reactor (BWR) designed by General Electric with a capacity of 620 MW. From its commissioning in 1972 until its shutdown on December 29, 2014, the facility provided 71.8% of Vermont’s electricity produced within the state in 2008, fulfilling about 35% of the overall state electricity demand. The plant utilized the Connecticut River as its cooling source.

Initially authorized to function for four decades, the Nuclear Regulatory Commission (NRC) granted a 20-year license extension to Vermont Yankee in 2011. Nonetheless, operational difficulties emerged when Vermont’s state legislature asserted jurisdiction over the plant’s ongoing operation by mandating a state certificate of public good (CPG). Although the legislature denied the renewal in 2010, Entergy successfully overturned this decision through litigation in 2012. In August 2013, Entergy declared that economic considerations would lead to the plant’s closure by late 2014, culminating in its official shutdown on December 29.

Since the 1970s, Vermont Yankee encountered substantial opposition, including demonstrations following the Fukushima disaster in 2011 and during its original license expiration period in 2012. The plant’s initial NRC licensing was also pivotal in the landmark 1978 U.S. Supreme Court ruling Vermont Yankee Nuclear Power Corp. v. Natural Resources Defense Council, Inc., which established important precedents for administrative law related to regulatory processes.

Design and function

Vermont Yankee featured a BWR-4 Boiling water reactor housed within a Mark I containment system. In 2008, it contributed to 71.8% of Vermont’s electricity generation and satisfied 35% of the state’s total power consumption.

Originally designed for an electrical output of 500 MW, upgrades completed by 2006 increased capacity to 620 MW. The reactor produced thermal energy at a rate of 1912 MW, which was converted into electrical power at an efficiency rate of approximately 32%. For context, Vermont’s average residential electricity demand in 2012 was around 239 MW. The nearby Northfield Mountain hydroelectric plant was constructed to complement Vermont Yankee’s consistent base load by utilizing pumped storage to absorb surplus off-peak energy.

The reactor core could hold up to 368 fuel assemblies alongside 89 control rods. Its spent fuel pool had authorization to store as many as 3,353 spent fuel assemblies.

Ownership and operational license

In the landmark Vermont Yankee Nuclear Power Corp. v. Natural Resources Defense Council, Inc. case decided by the United States Supreme Court in 1978, the Vermont Yankee reactor was central to affirming that courts lack authority to impose procedural requirements on the NRC, as such actions exceed judicial review limits.

On July 31, 2002, ownership transferred to Entergy Nuclear Vermont Yankee, LLC (EVY) following acquisition from Vermont Yankee Nuclear Power Corporation (VYNPC) for $180 million. This transaction encompassed the reactor facility, nuclear fuel inventory, real estate assets, decommissioning responsibilities, and trust funds totaling approximately $310 million. Additionally, a decade-long power purchase agreement (PPA) was included whereby three former owners agreed to purchase a share of generated electricity at roughly 4.5 cents per kilowatt-hour.

By May 6, 2006, Vermont Yankee had attained an NRC-approved Extended Power Uprate level of 1,912 MWth—representing a 20% increase over its initial licensed thermal power rating of 1,593 MWth. This enhancement was implemented incrementally to evaluate steam dryer performance according to NRC’s power ascension testing protocols.

As of 2008, about 600 employees worked at Vermont Yankee, including personnel based at its corporate headquarters in Brattleboro, Vermont.

Cooling water

The Vermont Yankee facility obtained its cooling water from the Connecticut River to support two primary systems: the circulating water system, which dissipated heat from the main condenser during electricity generation, and the service water system, responsible for cooling auxiliary equipment and managing decay heat during shutdowns or emergency conditions.

Electricity production

**Annual Generation (**MWh) at Vermont Yankee Nuclear Power Plant
Year	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Total Annual Output
2001	391,996	355,360	357,555	328,187	129,478	372,189	379,097	371,824	365,191	384,957	378,276	357,010	4,171,120
2002	392,352	343,305	349,713	338,459	209,953	372,559	372,809	365,720	349,961	93,192	380,204	394,389	3,962,616
2003	394,170	343,479	393,094	380,067	387,278	368,768	370,028	377,983	308,413	353,639	378,082	389,151	4,444,152
2004	392,688	366,832	391,126	36,007	319,916	209,343	287,777	367,658	360,891	376,536	368,682	380,564	3,858,020
2005	365,760	344,961	380,316	327,910	378,106	358,865	326,287	360,452	352,417	265,384	227,835	383,254	4,071,547
2006	383,337	343,081	400,542	420,472	440,374	445,119	455,681	441,760	432,747	462,863	415,434	465,113	5,106,523
2007	463,654 ... [table continues similarly through 2014] ...
2015													0

Closure and license extension efforts

On January 27, 2006 Entergy Vermont Yankee submitted an application to the Nuclear Regulatory Commission (NRC) seeking a 20-year extension of its operating license. However in early 2010 the Vermont State Senate voted 26 to 4 to prevent the Vermont Public Service Board from reviewing any proposals for continued operation of the plant.

The NRC concluded its review process on March 10, 2011 and subsequently granted the license renewal on March 21 of that year. This extended Vermont Yankee's authorization to operate until March 21, 2032.

Despite this federal approval on April 14th 2011 Entergy initiated legal action against Vermont in an effort to maintain plant operations following the state Senate’s opposition. On August 14th 2013 a U.S. Court of Appeals decision upheld Vermont Yankee’s ability to keep running based on federal preemption under the Atomic Energy Act of 1946 concerning safety oversight.

Nevertheless on August 28th 2013 Entergy announced plans to shut down and begin decommissioning by late 2014 citing economic challenges including competition from cheaper natural gas power sources. The plant ceased generating electricity at precisely 12:12 pm EST on December 29th 2014. By January 12th 2015 all nuclear fuel had been transferred into the spent fuel pool and by August 2018 remaining spent fuel assemblies were relocated into dry cask storage.

In December 2014 Entergy filed its Post Shutdown Decommissioning Report estimating total dismantling costs at approximately $1.24 billion. This figure contrasted with $665 million accumulated during four decades of operation. The company intends to finance the funding gap through outside borrowing.

On September 28th 2016 Entergy conducted an auction selling over one thousand pieces of equipment from the Brattleboro site. Notably two cooling towers were demolished in July 2019 representing a significant step forward in the decommissioning process.

2007

The plant's steam condenser was cooled using water sourced from the nearby Connecticut River, which remained separate from the reactor system and contained no radioactive material. When river temperatures surpassed environmental permit thresholds, cooling towers were employed to reduce water temperature before discharge. In 2007, the fourth segment of the west cooling tower collapsed, releasing non-radioactive cooling water. This industrial incident did not compromise the reactor’s safety or result in any radiation release. The Nuclear Regulatory Commission (NRC) verified that sufficient cooling capacity remained to maintain full operation; however, the reactor operated at half power until September 16, 2007.

Investigation revealed the collapse stemmed from corrosion in steel bolts combined with decayed wood. In response, Entergy pledged to implement more rigorous inspection protocols to avoid similar incidents in the future.

2008

Following the cooling tower failure, Vermont Governor Jim Douglas raised concerns regarding the plant’s dependability. In March 2008, a State Senate committee advised establishing an independent panel to evaluate the plant’s reliability. This panel delivered an overall favorable report; Public Service Commissioner David O'Brien affirmed there were no operational or safety grounds to mandate plant closure.

During a routine triannual inspection conducted by the Nuclear Regulatory Commission between July and August 2008, three minor issues were identified. An Associated Press article highlighted that the plant received commendable evaluations.

2009

During May 2009 reliability hearings before the Public Service Board (PSB), Vermont Yankee’s vice-president of operations expressed skepticism about the presence of radioactively contaminated underground piping but committed to verifying and providing clarification. By October 2009, Arnold Gundersen, serving on a special oversight committee appointed by the Vermont General Assembly, confirmed that radioactive contamination had indeed been detected in underground pipes. Entergy later characterized the earlier statement as a "miscommunication." On June 4, 2010, Vermont Public Radio reported Entergy Nuclear would bear legal costs arising from providing inaccurate information.

2010

In January 2010, the Vermont Department of Health announced detection of tritium—a radioactive isotope of hydrogen—in groundwater from a monitoring well sampled the previous November. Initial measurements were below EPA drinking water standards but increased by mid-January to 20,000 picocuries per liter (pCi/L), reaching federal limits. The NRC allocated additional resources to address these concerns and anticipated identifying the leak source within weeks.

By February 4, 2010, samples from a newly installed monitoring well revealed tritium concentrations around 775,000 pCi/L—more than 37 times above federal limits—while an underground vault sample measured 2.7 million pCi/L. The leak was traced on February 14 to steam pipes located within the Advanced Off-Gas pipe tunnel; subsequent repairs halted further leakage.

Testing performed by health departments in Vermont and New Hampshire on river and potable water sources detected no tritium presence.

During this probe, elevated levels of cesium-137 were discovered in soil near the facility—ranging from three to ten times normal background—but contamination was confined to approximately 150 cubic feet of soil with no health risk or migration potential. This cesium likely originated from defective fuel assemblies predating 2001.

On May 20, 2010, the NRC issued a report concluding that Entergy-Vermont Yankee had adequately assessed contaminated groundwater in terms of public safety and complied fully with regulatory standards; no violations or significant findings were noted.

In early November 2010, a water leak caused by a faulty weld led to a precautionary four-day shutdown for pipe repairs. A company representative indicated that earlier detection might have allowed repairs without necessitating shutdown.

Also in 2010, Vermont Electric Power Company (VELCO) constructed the Vernon Substation on Vermont Yankee’s property as a new primary transmission hub connecting a new 345 kV line to Central Vermont under its Southern Loop initiative. The existing Entergy-owned substation was outdated and unable to support additional lines or transformers. The Vernon Substation introduced a second 345 kV to 115 kV transformer for redundancy and enhanced offsite power reliability. Four transmission lines that previously connected directly to Vermont Yankee’s substation were rerouted to Vernon Substation, which is linked back via three tie-lines capable of transmitting the plant’s full output.

2011

During the week of January 17, 2011, tritium was found at a concentration of 9,200 picocuries per liter—below the federal threshold for reporting—approximately 150 to 200 feet north of the location where it had been detected the previous year. Bill Irwin, the radiological chief at Vermont Health Department, alongside Vermont Yankee spokesperson Larry Smith, indicated that the origin of the leak remained unidentified. Both Irwin and Governor Peter Shumlin voiced their concerns regarding this discovery.

2012

On January 19, 2012, Judge J. Garvan Murtha determined that Vermont lacked the authority to mandate the shutdown of Vermont Yankee, since state laws concerning radiological safety are under the exclusive jurisdiction of the Nuclear Regulatory Commission (NRC). Additionally, the judge prohibited the state from compelling Entergy to sell electricity to local utilities at discounted rates as a prerequisite for continued plant operation.

2013

On June 7, 2013, Entergy received approval from Vermont's Public Service Board via a Certificate of Public Good to install an external diesel generator intended to replace a hydroelectric tie line as the backup power source in case of a station blackout. This independent generator would activate solely if the primary emergency generators failed, supplying power to control room instruments and emergency cooling system components without depending on plant cooling water.

On August 27, 2013, Entergy announced plans to cease operations at Vermont Yankee by the end of 2014. The decision was attributed to depressed energy prices caused by increased shale gas production combined with elevated operational expenses.

Protests and politics

In 1971, Esther Poneck spearheaded opposition through the New England Coalition on Nuclear Pollution against constructing Vermont Yankee. Throughout the 1970s and 1980s, numerous anti-nuclear demonstrations targeted the plant, frequently attempting to obstruct access. Notable recent protests include:

January 2006: Approximately 100 anti-nuclear advocates gathered at Entergy Nuclear’s entrance; eleven individuals were arrested for trespassing.
April 2009: Around 150 protesters marched in Montpelier urging legislators to endorse renewable energy initiatives and shut down Vermont Yankee; their efforts were supported by 12,000 signatures.
January 2010: A coalition of roughly 175 activists undertook a 126-mile walk from Brattleboro to Montpelier opposing the plant’s relicensing.

In February 2010, the Vermont Senate voted 26 to 4 against permitting the Public Service Board to re-certify Vermont Yankee beyond its 2012 license expiration. This decision cited concerns including radioactive tritium leaks, deceptive testimony from plant officials, a cooling tower failure in 2007, among other issues. Some local businesses expressed unease about the absence of a definitive plan to replace the plant’s electricity generation. IBM, Vermont’s largest private employer and electricity consumer, stressed the importance of adopting more intelligent energy strategies. Larry Reilly, president of Central Vermont Public Service Corp., stated in 2011 that he was unconcerned about potential closure due to sufficient alternative power availability. An analysis by the University of Vermont projected that retail electricity rates would increase modestly—by just over three percent—if Vermont Yankee were to close.

Former Governor Peter Shumlin was a vocal critic of Vermont Yankee. Just two days after his November 2010 election victory, Entergy sought potential buyers for the facility but withdrew it from sale consideration by March 2011.

Following the Fukushima nuclear disaster in March 2011, approximately 600 individuals protested outside Vermont Yankee. On March 22, after the NRC extended Vermont Yankee’s operating license, Vermont’s congressional delegation—Senators Patrick Leahy and Bernie Sanders along with Representative Peter Welch—issued a joint statement condemning the NRC’s decision and underscoring parallels between Vermont Yankee and Fukushima reactors.

In March 2012, over 130 protesters were arrested at Vermont Yankee’s corporate headquarters on its first day operating beyond its original license expiration. In March 2013, more than 500 demonstrators marched through downtown Brattleboro calling for the plant’s closure.

Seismic risk

According to assessments by the Nuclear Regulatory Commission, the likelihood of an earthquake occurring that could inflict core damage at Vermont Yankee is approximately 8.1 in a million annually, equating to one event every 123,000 years. This evaluation is grounded in data from a 2008 USGS survey combined with a 2010 NRC analysis.

Surrounding population

The NRC establishes two distinct emergency planning zones for nuclear facilities: a 10-mile radius plume exposure pathway zone designed to address airborne radioactive hazards, and a broader 50-mile ingestion pathway zone focused on the risk of consuming contaminated food and beverages.

In 2010, the population residing within the 10-mile radius of Vermont Yankee was recorded at 35,284 individuals, reflecting a 1.4% growth since 2000. The number of residents within the 50-mile zone reached 1,533,472, marking a 2.9% increase over the same period. Nearby urban centers include Brattleboro, VT (6 miles away), Keene, NH (16 miles), Fitchburg, MA (38 miles), as well as Greenfield and Northampton in Massachusetts.

Starting in April 2016, coinciding with decommissioning activities, the designated emergency planning zone was scaled back to encompass only the plant’s immediate site boundaries.

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