“BUCHANAN — The likeliest source of the radiation leak at Indian Point is a huge holding tank filled with water that cools and shields used plutonium fuel rods hot enough to catch fire if the pool were drained — and dangerous enough to kill anyone who comes in contact with them.
“If you were exposed in close proximity, unshielded, it would be fatal,” Neil Sheehan, the spokesman for the Nuclear Regulatory Commission, said of the processed uranium pellets used to help generate thousands of megawatts of electricity at Indian Point. “We’re talking here about high-level, radioactive waste.”
Concerns about the leak have grown, especially since strontium 90, a byproduct of uranium and plutonium, was found in monitoring wells near the Hudson River. At elevated levels in drinking water, the isotope increases the risk of cancer.
NRC officials say it is the only case of strontium 90 leaking at any of the nation’s 103 working nuclear plants, but that it has not reached drinking water sources near Indian Point.
Tritium and nickel 63 also have been detected, but not at levels that alarm regulators.
To keep workers and the public safe, Indian Point maintains three spent fuel pools, using 90-degree water as both a shield and a cooling mechanism for its nuclear fuel rods.
The 30-foot-by-30-foot pool that company officials are looking at sits next to Indian Point 2, a reactor that powered up about the time President Nixon resigned, and a few months before Indian Point 1 shut down in October 1974.
Despite sitting in a half-inch- thick stainless-steel liner surrounded by concrete up to 6 feet thick, water from the 400,000-gallon pool began seeping through a hairline crack at the base of the structure in August. The breach has led to a special inspection by the commission, the drilling of 23 new testing wells, and public concerns about safety.
“You don’t want to lose any water in the pool,” said Jim Steets, the spokesman for Entergy Nuclear Northeast, the company that owns the two working nuclear reactors at Indian Point. “But a lot of the things we deal with every day are dangerous. What’s important is knowing how to deal with them.”
NRC scientists have said repeatedly that the leak does not constitute a threat to public health. Still, the perception of a radioactive leak of any kind has some residents of the Lower Hudson Valley concerned.
“There’s got to be a defect in the steel wall of some kind,” said Buchanan resident Jim Siermarco, who worked with radioactive isotopes early in his career at IBM and monitors Indian Point as a volunteer for the village.”There’s a pinhole or a crack somewhere. If it’s down where the fuel rods are, it’s going to take time to fix it.”
Entergy officials say that’s a strategy they’re pursuing, after having little success inspecting the two-thirds of the 40-foot-deep pool accessible to divers.
The remaining portion will require special underwater cameras and robotics to go where the fuel assemblies sit in racks in bundles of about 200 fuel rods, each about 12 feet high.
Company officials say they believe they have found a vendor qualified to inspect that area and apply special epoxy to any flaws that turn up. Entergy has encapsulated the cracks on the exterior walls, and now says that leakage has stopped.
But with strontium 90, tritium and nickel 63 showing up in numbers not seen on the site before, experts say they believe there is still radiated water leaking from somewhere.
One possibility is that the stainless-steel liner is intact, but that the water from an earlier leak in the liner — since patched — has finally found its way through the more porous concrete. The escaped water could date back to when Consolidated Edison ran the plant in the 1990s.
So far, tests to determine whether the leak started more than a decade ago have been inconclusive, but are continuing.
The water has traveled to a monitoring well within 50 yards of the Hudson River, bringing the isotopes with it. The water is still contained on the site, and has not reached drinking water sources, the NRC said.
One longtime industry watchdog said Entergy’s efforts to find the source of the leak and determine the extent of contamination show that Indian Point officials see the economic advantage of running a safe plant.
“The company could have tried to explain away a lot of what they’ve found with some hand-waving,” said David Lochbaum, a nuclear safety engineer with the Union of Concerned Scientists, an independent nonprofit alliance of citizens and scientists. “They seem to be going after a comprehensive set of answers.”
Though there has been a lot of data and scientific analysis of the leak since September, federal and company officials agree that the list of questions continues to grow, and will require methodical research to finish.
“There are several remediation strategies that we can follow,” said Steets, Entergy’s spokesman. “We haven’t reached the point where we know what is best to do. If this thing were on the edge of a public safety issue, we would be taking mitigation measures sooner. Some of this just takes time. We don’t want to make too quick a decision out of reaction to the public interest in this.”
Steets said the company also is looking closely at the fuel pool of the defunct Indian Point 1.
That pool leaks 25 gallons of radiated water a day into a specially built set of curtain drains. The drains capture water and allow it to be measured for radioactivity before it is released in accordance with the plant’s permits.
During heavy rainstorms, however, the capacity of that system and its drains and holding tank are pushed to their limits, Steets said.
The future appears to be dry cask storage. Entergy officials are creating a site for storing its nuclear waste in containers that seal the expended fuel pellets and cool them with helium or inert gases instead of water. Eventually, the hope is to move them to a safe, national storage site.
The fuel pools would still be necessary to allow for a long-term cool-down period — probably five years — but wouldn’t be the only storage method on site.
“Most plants are running into a space crunch,” said the NRC’s Sheehan. “At some point you have to look at alternatives to store the waste.””
To view the complete article, search the archives at the link below: