For the first time in 60 years, Hanford’s Plutonium Finishing Plant is off the electrical grid.
Power has been disconnected for the safety of workers doing the final cleanout of the main portion of the plant and the workers who are tearing the plant down.
Demolition of the plant’s Plutonium Reclamation Facility resumed this week after being stopped when an alarm sounded Jan. 27, indicating the spread of radioactive material. Demolition is now being done on the third and fourth floors.
Demolition on the facility at one end of the plant started in November, followed by the start of demolition of the McCluskey Room, while final preparations are made for demolition of the larger, main production portion of the plant.
It is expected to be the most hazardous demolition project at Hanford. The plant was used during the Cold War to turn plutonium in a liquid solution into buttons the size of hockey pucks or a powder, to be shipped to the nation’s nuclear weapons production facilities.
Nearly two-thirds of the plutonium for the nation’s nuclear weapons program during the Cold War was processed in the Hanford Plutonium Finishing Plant.
Hanford officials had hoped to resume demolition sooner, but an unusually cold and snowy winter delayed work using heavy machinery to tear down the Plutonium Reclamation Facility. A spray of water is one method used to prevent the spread of radioactive material, and the spray turns to snow in cold weather.
More time also was needed than originally anticipated to recover from the contamination spread.
Work to clean up the rubble pile left from demolition on Jan. 27 — the source of the contamination spread — was done carefully and deliberately.
The source of the contamination in the rubble was not identified, said Kelly Wooley, deputy project manager for the Plutonium Finishing Plant for Department of Energy contractor CH2M Hill Plateau Remediation Co.
Spot checks and field surveys were done as the rubble was loaded out, but a decision was made that sending a worker into the rubble pile for a closer look did not justify the risk to the worker.
Some 4.4 tons of scrap plutonium had to be converted into safer forms during the long years of preparing the Plutonium Finishing Plant for demolition this year.
The McCluskey Room is on track to be down to slab on grade first, likely this month, Wooley said. The entire plant must be down to slab on grade by a legal deadline that was extended until Sept. 30, which DOE now anticipates meeting.
Cleanout of the Plutonium Finishing Plant has been under way for about two decades, starting with stabilizing plutonium left at the plant at the end of the Cold War.
For the last steps to prepare the main portion of the plant for demolition, temporary lighting is being used. Disconnecting from the electric grid is safer for demolition crews and for other workers, including those removing asbestos around piping inside walls where there also could be electrical wiring.
Other final preparations include removing the vacuum line used to move radioactive material from one glovebox to another, removing a contaminated ventilation system exhaust line, and filling a drain system beneath the building with epoxy to stabilize contamination.
Change rooms and radiological surveying stations for workers leaving the plant have been moved to temporary trailers to prepare for demolition of the main portion of the plant.
The Plutonium Finishing Plant has experienced work crews and many of the ideas on how to prepare for the demolition have come from workers, Wooley said.