Contaminated water leaking from the Indian Point Nuclear Reactors forced plant owner Entergy to explain why. At an open house last week industry experts, hydrologists and spent-fuel experts hired by the company attempted to explain the unknown origin of large amounts of leaking, radiated water. Learning about the complex problem from Entergy’s perspective, members of the public stopped at each of the dozen exhibits set up at Entergy’s training center.

Underground lakes

Entergy’s Don Mayer, director of special projects for the Buchanan plant, explained how two lakes of radiated water had amassed under the plant’s transformer yard and under the Unit 1 reactor.

“Leaking was taking place under the prior owner in the early 1980s,” said Mayer.
“Also, sometime between 2000 and 2005 a leakage occurred that made its way into the plume. That’s all we know.” Mayer, referring to the lakes as “plumes,” said one lake was predominantly laced with tritium, while the other contained mainly Strontium-90. According to a recent report by the National Academies of Science, Strontium-90 is a dangerous radioactive isotope that increases the risk of cancer, and tritium is a known carcinogenic and mutagenic. In August 2005, radioactive leaks were thought to have come from the 40-foot-deep spent-fuel pools containing over 1,000 tons of extremely high radioactive fuel on-site. Spent-fuel pools are 40-foot deep pools that store used radioactive fuel.

New monitoring wells

The underground lake with tritium is about 90 by 200 feet and about 50 feet deep, according to Mayer. “The other one is 30 feet wide by 300 feet long and 50 to 60 feet deep,” he said. Entergy has dug 35 new water-monitoring wells, trying to detect where the leaks are coming from. The total number of monitoring wells at plant is up to 54.
“The wells are 50 feet to 120 feet,” said hydrologist Matt Bavenik, speaking at the open house about the monitoring wells.

Entergy is planning different types of remediation, explained Mayer. “We will do a pilot remediation test where we pull the tritium out of the ground,” he said. “Our primary purpose is to keep it here and not have it flow south to the river.”

Not an easy fix

“Tritium remediation is very difficult,” said Dan Hirsch of the Committee to Bridge the Gap, a nuclear watchdog group that studies the effects of radiation. In a phone interview, Hirsch said it was almost impossible to remove tritium. “Most contaminates are either dissolved or suspended in the water. If it’s suspended you can filter it out; if it’s dissolved you can run it through things like charcoal ion resins.” Because tritium combines with oxygen to form a liquid it actually is the water, said Mr. Hirsch. “It’s nothing you can filter out, nothing you can readily remove. You can get it out by breaking the water apart with electrolysis, which is immensely expensive.”

Other radionuclides from the spent-fuel pools are heavier isotopes like Strontium-90 and Cesium 137, that don’t travel with water as well. “These are also very bad radionuclides,” said Mr. Hirsch. “But at least you can remove them from water.”
Clean-up work on the leaks is expected to start at the end of the month, said Mayer.

Dumping in the Hudson

Most of the radiated water is flowing into the Hudson River, where the plant is located. “We want to remediate that and try to contain the water and control where it flows,” said Mayer.

The plant dumps over 10 million gallons of radiated water into the Hudson River every year, according to the 2005 Annual Radioactive Effluent Release Report Entergy filed with the federal Nuclear Regulatory Commission in April of 2006.

Nearby residents and environmental advocacy groups such as Riverkeeper worry that radiated water will reach the public drinking supply and will affect bathers at the Croton Point Park beaches.

Neil Sheehan, spokesperson for the Nuclear Regulatory Commission, said last spring that drinking water supplies tested two miles away from the plant tested free of contaminants.
Phillip Musegaas, a policy analyst with Riverkeeper based in Tarrytown, said he hopes that Entergy can find the source of the leaks. “Then they will be able to get a plan going to clean it up,” he said. “Right now, it’s difficult to know just how much contamination is going into the environment.”

Musegaas said Entergy’s effort was due in part to their upcoming relicensing application. “We have to keep in mind that they trying to put their best face forward,” he said. “But contaminating the river is a serious problem. Tens of thousands of gallons of water are leaching out into the ground and most of it is going into the river.”