Last March, a tsunami damaged the cooling systems of three reactors at the Fukushima Daiichi nuclear plant, causing the leak of high levels of radiation. The Japanese government and plant owner Tokyo Electric Power Company recently released their clean-up plan: a 40-year process of isolating the facility, draining fouled water and dismantling the buildings. By Marina Koren
2012: Engineers install equipment that removes radioactive atoms migrating into under ground water and seawater. The land must be repeatedly mapped for contamination because rain distributes the material unevenly in the soil. “It’s not a uniform distribution,” says Norman Kleiman, an environmental health sciences researcher at Columbia University’s Mailman School of Public Health in New York. “We have potential hotspots of contamination here and there.” Irradiated soil is removed and stored in secure silos.
2014: Workers begin to remove debris using remote-control robots. Contractor Takenaka Construction has already purchased demolition robots to tear down irradiated buildings. The company extended the 1 950 kg robots’ range, added a video camera, and hardened them against contamination. “High fields of gamma radiation can cause plastics and electronic chips to degrade,” says Lake Barrett, who supervised the clean-up at Three Mile Island for the US Nuclear Regulatory Commission.
2015: Workers use newly invented chemical sealants to plug holes in areas of the plant flooded with radioactive water. They drain the water from the reactor building and employ custom-made underwater robots to collect debris from inside the spent-fuel pools.
2016: A cover for the reactor building is installed to enclose the space. Additional video cameras monitor teleoperated work inside the reactor and turbine buildings, which are drained and repaired.
2022: Removal of the fuel rods from the damaged reactors begins. The rods have melted and fallen apart, complicating the clean-up.
2030 and beyond The last of the fuel is removed from the reactor buildings. Demolition crews then dismantle the entire facility, a process that takes decades.