One of the nuclear reactors at Brookhaven National Laboratory has been completely decommissioned, officials from the federal Department of Energy announced this week.
In June, the last shipment of radioactive materials from the lab's Graphite Research Reactor was sent to disposal facilities. The materials came from the demolition of the reactor's shield, originally measuring 55 feet long, 37 feet wide and 33 feet tall, that protectively surrounded the reactor core.
The shield, with its 4-foot-thick concrete walls encased in 3-inch-thick steel, was made of 4,760 tons of steel and concrete and was part of nearly 24 million pounds of radioactive waste from the reactor that's been removed and shipped to disposal sites in Nevada and Utah.
Dismantling the shield took about two years, according to the Energy Department. The decommissioning of the reactor started in 1997 and has cost the government about $148 million.
"This is a major milestone for us, for the Department of Energy, and the nation, as it's the first time a U.S. reactor of this type and size has been completely dismantled," George Goode, BNL's assistant laboratory director for environment, safety and health, said in a news release.
In an interview, he added, "It did some incredible research, but after its mission was over and we had replaced it with the High Flux Beam Reactor, it sat for many, many years basically occupying space, and there's a risk for it to be there," Goode said. "But we executed the whole project without any loss of control over the project."
"The work completed here demonstrates what can be accomplished by people with vision, with determination, and with corresponding goals," Thomas D'Agostino, the Energy Department's undersecretary for nuclear security, said in the release. "That vision began with the idea of safely decommissioning a research facility that served its nation well."
An asphalt cap system has been installed around the building that housed the remains of the reactor to prevent seepage into underground water supplies, and a groundwater monitoring system has been installed. The 320-foot-tall stack is scheduled for removal by 2020.
Built in 1947, the BGRR was the first reactor in post-World War II America constructed for "peacetime atomic research," according to the Energy Department. The reactor started operating in 1950. More than 25,000 scientific experiments, including research on medical isotopes, were performed until 1968, when a more efficient reactor was built next to the BGRR and rendered it obsolete.
The lab has no operating reactors, and the two remaining reactors are in safe storage mode, awaiting the completion of their decommissioning, according to the Energy Department.