ST. PAUL, Minn. — Minnesota regulators said Thursday they are monitoring the cleanup of a 400,000-gallon leak of radioactive water from Xcel Energy’s Monticello nuclear power plant, and the company said there is no danger to the public.
“Xcel Energy took swift action to contain the leak at the plant site, which does not pose a risk to the health and safety of the local community or the environment,” the Minneapolis-based utility said in a statement. a statement.
Although Xcel reported the tritium-containing water leak to state and federal authorities in late November, the spill had not been made public before Thursday. State officials said they waited for more information before making it public.
“We knew tritium was present in a monitoring well, however Xcel had not yet identified the source of the leak and its location,” said Michael Rafferty, a spokesman for the Minnesota Pollution Control Agency.
“Now that we have all the information about where the leak occurred, how much was released into the groundwater, and that the contaminated groundwater had moved beyond the original location, we are sharing this information,” he said, adding that the water remains contained in the Xcel property. and does not pose an immediate risk to public health.
The company said it notified the federal Nuclear Regulatory Commission and the state on November 22, a day after confirming the leak, that it came from a pipeline between two buildings. Since then, it has been pumping groundwater, storing and processing the contaminated water, which contains tritium levels below federal thresholds.
“Continuous monitoring of more than two dozen monitoring wells at the site confirms that the leaked water is fully contained at the site and has not been detected beyond the facility or in any local drinking water,” the Xcel statement said. Energy.
When asked why Xcel Energy did not notify the public sooner, the company said, “We understand the importance of promptly informing the communities we serve if a situation poses an immediate threat to health and safety. In this case, there was no such threat.” The company said it was focused on investigating the situation, containing the affected water and figuring out next steps.
The Monticello plant is about 35 miles (55 kilometers) northwest of Minneapolis, upstream of the city on the Mississippi River.
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 doesn’t travel very far and cannot penetrate human skin, according to the NRC. A person drinking water from a spill would only receive a low dose, the NRC says.
The NRC says that tritium spills occasionally occur at nuclear plants, but it has repeatedly determined that they have been kept confined to plant property or involved off-site levels so low that they did not affect health or safety. public security. Xcel reported a small tritium leak at Monticello in 2009.
Xcel said it has recovered about 25% of the tritium spilled so far, that recovery efforts will continue, and that it will install a permanent solution this spring.
“While this leak does not pose a risk to the public or the environment, we take it very seriously and are working to safely address the situation,” said Chris Clark, president of Xcel Energy–Minnesota, North Dakota and South Dakota, in the statement. statement. “We continue to collect and treat all potentially affected water while regularly monitoring nearby groundwater sources.”
Xcel Energy is considering building aboveground storage tanks to store the contaminated water it reclaims, and is considering options for treatment, reuse or final disposal of the collected tritium and water. State regulators will review the options the company selects, the MPCA said.
Japan is preparing to release a massive amount of treated radioactive wastewater from the triple reactor meltdown 12 years ago at the Fukushima Daiichi nuclear power plant into the sea. The water contains tritium and other radioactive contaminants.