Vermont Yankee Nuclear Power Plant Tritium Incident

Tatyanna Dadabbo
April 19, 2017

Submitted as coursework for PH241, Stanford University, Winter 2017

Brief History

Fig. 1: The Vermont Yankee Nuclear Power Plant in Vernon, Vermont. (Source: Wikimedia Commons)

The Vermont Yankee Nuclear Power Plant was ranted a permit to be built by the Nuclear Regulatory Commission in 1967 and began operating in 1972. [1] Vermont Yankee is a boiling water reactor type nuclear power plant. It is located in Vernon, Vermont on the banks of the Connecticut River in the southeast Vermont (see Fig. 1). It generated 620 megawatts of electricity, which provided for thirty percent of the state's electricity requirements. [2] Vermont Yankee Nuclear Power Plant was bought in 2002 by New Orleans-based Entergy Corporation. An amendment made in 2006 gave the state the final say authority to grant or deny permission if Entergy sought a plant operations extension past the 40 year federal license of plant operations. [3]

Upon taking over Vermont Nuclear in 2002, Entergy's intention was to file a renewal of the plant license that would extend the scheduled closing date of March 2012. The Nuclear Regulatory Commission is responsible for nuclear power plant license extensions, but Entergy also decided to seek out a permit from the Vermont Public Service Board. The Vermont Public Service Board is the state agency in charge of regulating electric utilities. With this decision, Entergy agreed to state oversight during the license renewal process. Entergy filed for the 20-year license extension with the NRC in 2006 and in 2008 filed a license extension request with the Vermont Public Service board. After arduous processes both licenses extensions were granted. [2]

2010 Tritium Incident

In 2010, a tritium leak in the underground pipes was found in the Vermont Yankee Nuclear Power Plant. Tritium is a radioactive isotope of hydrogen and is occasionally created in nuclear reactors when neutrons are absorbed by control rods containing nuclear fission in the reactor. In the case of Vermont Yankee the tritium was able to combine with oxygen in the coolant water producing "tritiated water". This type of water is corrosive and is able to leak through piping in the ground. Although the owner of the plant, Energy Corporation, originally denied the tritium leak, in January of 2010, they admitted that the pipes carrying this "tritiated water" exist and also admitted to a previous tritium leak in 2005. The source of this 2005 leak has yet to be found by Vermont Yankee engineers.

The NRC stated that this tritium leak did not pose any risks to human health and no samples from drinking water wells were found to have detectable amounts of tritium. Although this tritium leak had no health and safety risks, this incident did have a large impact on the future of the Vermont Yankee nuclear power plant. In light of this incident, Vermont's Senate voted in favor of closing down the plant 26-4 when the plant's operating license was set to expire in 2012. This decision made it unlikely that the company's application to the NRC would be approved for a 20-year license renewal. [4]

Decommissioning and Vermont Nuclear Today

Unfortunately, in August of 2013, Entergy announced that it would be retiring the Vermont Yankee Power Plant in late 2014 and operations officially ceased on December 2014. The reasons attributed to this decision were low natural gas prices and power market structures. Additionally, Entergy in their decision to decommission Vermont Yankee referenced flaws in power and capacity market design. [5] The future of the Vermont Yankee Nuclear Power Plant will be the decommissioning and reconstruction of the site.

© Tatyanna Dadabbo. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] "Vermont Yankee Nuclear Power Corp. v. Natural Resources Defense Council, Inc.," United States Reports, 435 U.S. 519 (1978).

[2] R. Watts and J. Maddison, "The Role of Media Actors in Reframing the Media Discourse in the Decision to Reject Relicensing the Vermont Yankee Nuclear Power Plant," J. Environ. Stud. Sci. 2, 131 (2012).

[3] M. Clayton, "Who Has Final Say over the Fate of Vermont Yankee Nuclear Power Plant?" Christian Science Monitor, 19 Jul 11.

[4] P. Gwynne, "Tritium Leak Triggers Reactor Shutdown in US," Physics World 23, No. 4, 7 (April 2010).

[5] D. Vine and T. Juliani, "Climate Solutions: The Role of Nuclear Power," Center for Climate and Energy Solutions, April 2014.