BUCHANAN, N.Y. – Indian Point Unit 2 was shut down Monday morning for its 20th refueling. Tons of spent fuel will be moved from the main reactor to the spent fuel pool over the course of the next few weeks.
Refueling at Indian Point Unit 2 happens about every two years, replacing one-third of the plant’s 193 nuclear fuel assemblies, plant officials said. About 65 assemblies will be replaced during this refueling. “Fuel assemblies” are groups of nuclear rods - each is a 10 inch square, 15 foot long group of nuclear rods with a useful life of about six years. After six years, most of the uranium in an assembly has been used and assemblies do not produce enough heat to efficiently power Indian Point’s steam driven turbine, which generates electricity, according to officials.
An army of about 900 contractors will converge on Indian Point to help with refueling and myriad tests and maintenance performed over the weeks it takes to refuel. Most workers will perform maintenance and tests that can’t be performed while the plant is operating, according to officials at the Nuclear Regulatory Commission.
Each 1,000 megawatt reactor core holds about 100 tons of fuel, according to government sources. Indian Point Unit 2’s spent fuel pool will contain about 935 spent fuel assemblies after one-third of the reactor’s assemblies are replaced. Indian Point Unit 3’s spent fuel pool is at capacity, containing about 1,350 fuel assemblies.
David Lochbaum, director of the Nuclear Safety Project for the Union of Concerned Scientists, said he finds packed spent fuel pools disconcerting and said fuel is far safer in dry casks. He said, because dry casks contain only 32 fuel assemblies and the likelihood of many failing at once is very small, if an event were to occur the consequences would be much smaller.
Lochbaum said moving the fuel into dry casks could provide additional time in emergency situations involving the spent fuel pool. Moving more spent fuel out of the pools would maximize the amount of water in the pools, allowing operators more time to fix cooling mechanisms should a failure occur, he said.
Jerry Nappi, spokesperson for Indian Point, said moving spent fuel is “a pretty large undertaking,” and that filling up casks can take weeks and requires approval from the NRC. He said the government waffled on its commitment to dispose of spent nuclear fuel for plants and now spent nuclear fuel has to be stored on site.
“I don’t mean to blame Entergy, because that’s standard practice across the country,” said Lochbaum. “It’s hard to make the risk any higher because the pools are stuffed with spent fuel.”
Lochbaum also noted that if terrorists were to choose a target, a spent fuel pool would be an “attractive option,” because of the density of radioactive material.
Lochbaum said he is also concerned about a cavity, similar to a tube, which transports assemblies from the reactor core to spent fuel pools. He said the cavity has leaked into a lower level of the plant for more than a decade. Diane Screnci of the NRC confirmed the cavity has a history of leakage, but it is only flooded with water during refueling.
“The Advisory Committee on Reactor Safeguards looked at it and determined that the condition was not an impediment to grant a renewed license,” she said, “We’ve found Entergy’s actions to be acceptable.”