Radiation levels at the Fukushima Daiichi nuclear power plant in Okuma, Japan have dropped significantly since the meltdown 14 years ago. Workers in many areas wear only surgical masks and regular clothes, but those entering the damaged reactor buildings must use full protective gear, including facemasks, gloves, socks, shoe covers, hazmat coveralls, a jacket, and a helmet. The monumental cleanup effort to remove melted fuel debris from the reactors, which could take over a century, presents workers with high levels of radiation and psychological stress. The Associated Press recently visited the plant to observe the progress.
A remote-controlled robot successfully retrieved a small sample of melted fuel from inside the damaged No. 2 reactor, marking an important step in the decommissioning process. There are plans for further sample retrieval missions to gather more information before larger debris removal efforts begin in the 2030s. Workers face challenges such as high radiation levels, limited visibility, and difficulty breathing and moving inside the reactor buildings. Despite setbacks, efforts continue to safely address the remaining melted nuclear fuel and debris within the plant.
The need for replacement arose when the workers’ highest individual radiation dose exceeded the overall average, but remained well below the 100-millisievert five-year limit. Despite this, a growing number of workers at the plant are expressing concerns regarding safety and radiation, according to Ono, the decommissioning chief, who referenced an annual survey of approximately 5,500 workers. In 2023, two workers suffered burns and were hospitalized after coming into contact with contaminated sludge at a water treatment facility, although they had no other health issues.
Focused on safety, Yokokawa and his colleague, Hiroshi Ide, who both participated in the 2011 emergency response, now lead teams working towards enhancing safety measures for workers exposed to high radiation levels in various areas of the plant. On the upper level of the No. 2 reactor, preparations are being made to extract spent fuel units from the cooling pool, scheduled to commence within the next two to three years. Meanwhile, at the No. 1 reactor, workers are constructing a large roof structure to contain radioactive dust during decontamination activities on the top floor prior to the removal of spent fuel.
To minimize radiation exposure and enhance efficiency, workers utilize a remote-controlled crane for assembling pre-fabricated components, as outlined by TEPCO. The No. 1 reactor and its vicinity are identified as some of the most contaminated parts of the plant. Additionally, workers are involved in the extraction of treated radioactive wastewater and have recently initiated the disassembly of emptied water tanks to create space for the construction of facilities necessary for the research and storage of melted fuel debris.
After multiple small-scale robotic missions to collect samples, experts will establish a comprehensive approach for removing melted fuel, starting with the No. 3 reactor. The daunting task of decommissioning the plant poses significant challenges that are just commencing. Although the government and TEPCO have set an initial target completion date of 2051, the retrieval of melted fuel debris is already three years behind schedule with numerous unresolved issues remaining.
Despite residing in a restricted area due to nuclear contamination, Ide, who hails from Namie town northwest of the plant, must don a hazmat suit even for brief visits back home. “As a Fukushima resident, my aim is to ensure that the decommissioning process is carried out effectively so that people can eventually return home without apprehension,” he expressed.
