VERNON — On Jan. 7, Entergy Nuclear Vermont Yankee spokesman Rob Williams wrote to the media, announcing that “for the first time, a small amount of tritium has been identified in a sample taken from a monitoring well at the plant” - the discovery that set into motion the events that have led to the extended controversy over the company's communications with its regulators.
Tritium is a naturally occurring radioactive form of hydrogen produced in the upper atmosphere by the interaction of cosmic rays and air molecules and as a byproduct of the nuclear power process. The substance is an example of a radionuclide, or radio isotope - an atom with an unstable nucleus.
At press time on Feb. 1, water from two new test wells tested positive for the isotope. Prior to that, the substance had been confined to an original 2007 test well near the reactor.
According to the Nuclear Regulatory Commission, tritium also “has several commercial uses in self-luminescent devices, such as exit signs in buildings, aircraft dials, gauges, luminous paints, and wristwatches. It is also used in life science research and in studies investigating the safety of potential new drugs.”
The Environmental Protection Agency notes that, “as with all ionizing radiation, exposure to tritium increases the risk of developing cancer. However, because it emits very low energy radiation and leaves the body relatively quickly, for a given amount of activity ingested, tritium is one of the least dangerous radionuclides.”
Because tritium can also act like regular hydrogen and can bond with oxygen to form water, resulting in tritiated water, its presence in pipes beneath the Vernon plant have caused various levels of community concern. Its chemical structure is identical to normal water and cannot therefore be filtered out.
The NRC describes the substance, with a half-life of 12.3 years, as “one of the least dangerous radioactive isotopes known. It emits very weak radiation and leaves the body relatively quickly. Since tritium is almost always found as water, if ingested, it goes directly into soft tissues and organs, and is expelled from the body along with the water.”
Other substances have cropped up in the search for the leak.
On Jan. 22, state inspectors found a trace amount of cobalt-60 in standing water in an underground trench, a concrete cavity or vault that provides clear access to pipes.
The isotope, a radioactive form of cobalt, “is also produced as a by-product of nuclear reactor operations, when structural materials, such as steel, are exposed to neutron radiation,” according to materials from the Environmental Protection Agency. The material emits strong gamma radiation, rendering external exposure or ingestion harmful.
'No impact on public health and safety'
“I would be remiss if I didn't point out that there has been no impact on public health and safety, and I wouldn't expect there to be one,” Nuclear Regulatory Agency Senior Public Affairs Officer Diane Screnci said.
As a consequence of the tritium discovery, Screnci said the NRC sent two radiation specialists to Vermont Yankee to provide specialized assistance to the two on-site NRC agents and to state health inspectors and plant employees, to make sure “VY is doing everything we think they should be doing.”
The specialists spent a week in Vernon, leaving Jan. 29. Their work included “looking at and analyzing what [Entergy] has done, the findings, how water flows.
Screnci described such nuclear power plant tritium leaks as “not uncommon.”
“From our perspective, it's important that if there's a leak, they know where it is and take steps to prevent it,” Screnci said, noting that the goal is to “gain a full understanding of what's going on there.”
The NRC investigators have 45 days to file a public report once they deem they have enough information from which to draw a conclusion, Screnci said.
According to the Nuclear Information and Research Service, a national antinuclear advocacy group, “power plants routinely and accidentally release tritium into the air and water as a gas (HT) or as water (HTO or 3HOH). No economically feasible technology exists to filter tritium from a nuclear power plant's gaseous and liquid emissions to the environment.”
The Canadian Coalition for Nuclear Responsibility has posted quotes from numerous scientific studies quantifying genetic mutations and cancers from much larger doses of the isotope. Because tritiated water is so easily ingested and otherwise indistinguishable from regular water, nuclear critics point to its capacity for exceptional harm to water-laden soft tissues in its journey through the human body.
Of economic concern is how the discovery of underground pipes carrying the tritium - a potential source of the leak - could affect the overall cost of decommissioning, already a subject of deep controversy in VY's relicensing journey.
According to nuclear engineer and consultant Arnold Gunderson of Fairewinds Associates in Burlington, unanticipated tritium found in the process of shutting down Connecticut Yankee “have driven the costs up and have had a real impact on the decommissioning.”
On Jan. 27, Senate President Pro Tem Peter Shumlin (a candidate for governor) and House Speaker Shap Smith, both Democrats, jointly wrote Department of Public Service Commissioner David O'Brien, formally requesting that the DPS reconsider Entergy's request to spin off ownership of Vermont Yankee to a new holding company, Enexus.
“The current crisis calls for a reexamination of this position,” Shumlin and Smith wrote, charging that cleaning up unanticipated radionuclides could “potentially double” the anticipated cost of decommissioning Vermont Yankee.
Voluntary program
Vermont Yankee was one of a number of plants that adopted a voluntary program developed by the Nuclear Energy Institute, which describes itself as a “policy organization of the nuclear energy and technologies industry and participates in both the national and global policy-making process.”
According to NEI Senior Media Relations Manager Tom Kauffman, the organization instituted the program in 2006, creating a protocol “where if tritium [leaks] outside the confines of the plant into the ground, the plant will notify local stakeholders, local officials, even if [the amount found] isn't close to the regulatory limits set by the NRC.”
Entergy, through its spokesman, Rob Williams, has sent multiple dispatches to the press reassuring the public and echoing Screnci's reassurances.
Neither Williams nor Director of Communications Larry Smith responded to multiple requests for clarification or further comment on the constellation of issues surrounding the tritium or the issues that emerged.
Alternatively, The Commons sought comment from more than a dozen Entergy employees who advocated for the plant's relicensing in letters to the editor this past fall.
“Is it bad? Of course it's bad,” said Vedrana Wren, a plant auxiliary operator, who has worked at the plant for five years.
“But what the newspapers don't tell you is if you drank this for a full year, you'd have less exposure than if you flew from Boston to London,” said Wren, one employee who agreed to speak about the recent plant issues on the record.
“The problem is the lack of context, the lack of comparison to reality . . . you hear '2,000 picocuries' and it sounds like a lot, but the fact of the matter is that you can have 2,000 picocuries in drinking water. This is information that even I, as a nuclear worker, have to seek. I have to get contextual information,” Wren added.
“There's plenty of room for improvement, but the comparative dangers? If you're scared of a nuclear plant, don't get in a car, don't cross the street; definitely don't eat genetically altered food and definitely don't smoke.”