The delay in notifying the public about the leak in November raised questions about public safety and transparency, but industry experts said Friday there was no threat to public health. They said Xcel Energy voluntarily notified state agencies and reported the tritium leak to the Nuclear Regulatory Commission shortly after it was confirmed and that the leak of 400,000 gallons (1.5 million liters) of radioactive water never met the threshold which required public notice.
“It’s something we struggle with because there’s such concern with anything nuclear,” said Victoria Mitlyng, a spokeswoman for the Nuclear Regulatory Commission. “The concern is very understandable. That’s why I want to make very clear the fact that the Minnesota public, the people, the community near the plant, are not and are not in danger.
State officials said that while they learned of the leak in November, they were waiting to get more information before making a public announcement.
“We know there is a presence of tritium through good monitoring, however Xcel does not yet know the source of the leak and its location,” Minnesota Pollution Control Agency spokesman Michael Rafferty said in a statement. Thursday. “Now that we have all the information on where the leak occurred, how much was released into the groundwater and that the contaminated groundwater moved beyond the original location, we are sharing this information.”
Tritium is a radioactive isotope of hydrogen that occurs naturally in the environment and is a common byproduct of nuclear plant operations. It emits a weak form of beta radiation that does not travel very far and cannot penetrate human skin, according to the Nuclear Regulatory Commission.
Edwin Lyman, director of nuclear power safety at the Union of Concerned Scientists, said that a significant health risk would only occur if people consumed sufficient amounts of tritium. That risk exists if the plume remains on the company’s site, which Xcel Energy and Minnesota officials say that is the case.
If regulatory officials are sure it hasn’t moved on site, people don’t have to worry about their safety, he said, adding that companies usually take action when on-site monitoring wells detect high levels. levels of contaminants such as tritium.
Mitlyng said there is no official requirement for nuclear plants to report all tritium leaks to the Nuclear Regulatory Commission. However, Xcel Energy previously agreed to report some tritium leaks to the state. When Xcel Energy shares information with the state, it also shares it with the commission.
The commission posted a notice about the leak on its website November 23, noting that the plant had reported it to the state a day earlier. The report classified the leak as a non-emergency. The announcement said the source of the tritium was being investigated at the time.
Beyond that, there was no widespread public notice before Thursday.
Rafferty said disclosure requirements fall on the facility, and state agencies will notify residents immediately if there is an imminent threat to health or the environment.
Rafferty said the Minnesota Pollution Control Agency decided to share information about its role in overseeing the cleanup now “because we have more details about the location and potential movement of the contamination, measures taken to control the plume and plans for remediation including short-term storage of contaminated water.”
Mitlyng said there is no way for tritium to get into drinking water. The facility has groundwater monitoring wells in concentric circles, and plant employees can track the progress of contaminants by seeing which wells detect higher amounts. There are Nuclear Regulatory Commission inspectors on site as well, monitoring the response.
The company said the leak was from a pipe between two buildings.
Xcel said it has recovered about 25% of the spilled tritium so far, that recovery efforts will continue and that it will install a permanent solution this spring.
Xcel is considering building above-ground storage tanks for the contaminated water it recovers and is considering options for treatment, reuse or final disposal of the collected tritium and water. State regulators will review the options chosen by the company, the state Pollution Control Agency said.
The regulatory commission says that tritium spills occur from time to time at nuclear plants, but they are limited to plant properties or associated with low levels offsite that do not affect public health. Xcel Energy reported a small leak of tritium at Monticello in 2009.
The Monticello plant is about 35 miles (55 kilometers) northwest of Minneapolis, upriver from the city on the Mississippi River.
Shelby Burma, who lives minutes from the spill site, said the news – in the coming weeks after a train derailment on the Ohio-Pennsylvania border has left concerns about contaminated air, soil and water in soil – made him worried about the increasing amount of chemicals in the environment.
“I think it’s shocking that they didn’t notify the public sooner,” Burma said. “They say it’s harmless, but it’s hard to believe when they’ve waited so long to make it public.”