Radiation levels at the Fukushima Daiichi nuclear power plant in OKUMA, Japan have significantly decreased since the catastrophic meltdown 14 years ago on Tuesday. While workers in many areas now only wear surgical masks and regular clothes, those who enter the reactor buildings – including the three damaged in the 2011 earthquake and tsunami – must wear full protective gear. This includes full facemasks with filters, multi-layered gloves and socks, shoe covers, hooded hazmat coveralls, a waterproof jacket, and a helmet.
Workers are currently engaged in the monumental task of removing melted fuel debris from the reactors as part of a nuclear cleanup effort that could span over a century. This work presents significant challenges, including high levels of radiation and psychological stress for the workers involved.
A recent visit by The Associated Press to the plant shed light on the ongoing efforts. A remote-controlled robot equipped with a tong recently retrieved a small piece of melted fuel from inside the damaged No. 2 reactor, marking a crucial milestone in the decommissioning process. The ultimate goal is to address at least 880 tons of melted nuclear fuel that has mixed with debris inside the three ruined reactors.
Akira Ono, chief decommissioning officer at the Tokyo Electric Power Company Holdings, emphasized that while the retrieved sample provides valuable information, more samples will be needed for the larger debris removal efforts planned for the 2030s. A second sample-retrieval mission at the No. 2 reactor is anticipated in the near future.
Despite efforts to reduce radiation levels in the reactor buildings, working conditions remain challenging. Workers inside the No. 2 reactor must contend with reduced visibility, breathing difficulties, and cumbersome protective gear. The mission to retrieve samples is carefully planned to minimize radiation exposure, with workers taking precautions such as taping around gloves and socks, and using personal dosimeters to measure radiation levels.
The mission encountered setbacks early on, with workers facing technical challenges due to the high levels of radioactivity present. Despite these obstacles, the dedicated team is persevering in their efforts to safely address the aftermath of the Fukushima Daiichi nuclear disaster.
The need for replacement of equipment arose, and the workers’ highest individual radiation dose exceeded the average but remained well below the 100-millisievert five-year limit. Despite this, a growing number of workers express concerns about safety and radiation levels at the plant, according to Ono, the decommissioning chief, who referenced an annual survey of approximately 5,500 workers. In 2023, two workers were injured after being splashed with contaminated sludge at a water treatment facility, leading to burns and hospitalization, although they did not experience any other health issues.
Ensuring Safety Yokokawa and his colleague, Hiroshi Ide, who assisted during the 2011 emergency, now serve as team leaders. They are dedicated to enhancing safety measures as workers operate in high radiation zones within the plant. On the upper level of the No. 2 reactor, preparations are underway to extract spent fuel units from the cooling pool, scheduled to commence within the next two to three years. Concurrently, at the No. 1 reactor, a substantial roof is being erected to contain radioactive dust generated during decontamination work on the top floor in anticipation of the spent fuel removal.
To reduce exposure and enhance productivity, workers employ a remote-controlled crane to affix pre-assembled components, as per TEPCO guidelines. The No. 1 reactor and its vicinity are identified as some of the most contaminated areas within the facility. What Lies Ahead? Workers are also engaged in removing processed radioactive wastewater, with recent efforts focused on disassembling emptied water tanks to create space for the construction of research and storage facilities required for the melted fuel debris.
Following a series of robotic missions to collect samples, experts aim to devise a large-scale method for extracting the melted fuel, starting with the No. 3 reactor. Decommissioning experts emphasize that the formidable task of dismantling the plant has only just commenced, with projections suggesting a timeline of over a century for completion. While the government and TEPCO aim for an initial deadline of 2051, the retrieval of melted fuel debris faces a delay of three years, alongside numerous unresolved challenges.
Ide, a resident of Namie town situated to the northwest of the plant and within a restricted zone due to nuclear contamination, is required to wear a hazmat suit even for brief visits home. “As a Fukushima resident, I am committed to ensuring the proper execution of the decommissioning process to facilitate the safe return of locals,” he remarked.
