It is not yet known whether the man's death was due to radiation exposure, and an autopsy is pending.
The Fukushima Daiichi plant suffered a series of meltdowns in 2011 during a massive earthquake and tsunami off the coast of Japan. The quake knocked out the plant's cooling systems, causing meltdowns in the plant's reactors and a radioactive leak that triggered the evacuation of thousands of people in the area.
In a statement released Monday, the plant's operator, Tokyo Electric Power (Tepco), said that the man had been taken to the emergency room after complaining that he wasn't feeling well. "His death was confirmed early in the afternoon," Tepco said.
Isabelle Dublineau, the head of the experimental radiotoxicology laboratory for France's Institute for Radiological Protection and Nuclear Safety (IRSN), said that, "there are many thresholds of radiation exposure." Speaking to VICE News Tuesday, Dublineau said it was "too early" to comment on the death.
This is the third recorded death at the stricken Fukushima plant since the start of the decommissioning work. In March 2014, a laborer at the plant was killed after being buried under gravel while digging, and in January 2015, a worker died after falling inside a water storage tank.
While the latest death has already been branded suspicious in the media, Tepco has so far denied that any of the deaths are related to radiation exposure.
On some days, radioactive emissions at the Fukushima plant can be as high as 2.16 millisieverts [mSv] — more than one-tenth of the allowed annual exposure for nuclear energy workers. As a result, workers are limited to three-hour shifts, and labor in grueling conditions, particularly in the summer, when the temperature can reach 113 degrees. The heat is made worse by the heavy protective gear worn by workers to protect themselves from radiation exposure — including suits boots, gloves and masks.
The worker who died over the weekend was working up to three hours a day at the plant, on the construction of the "ice wall" — an underground frozen wall designed to box in the melted reactors and contain the seeping radioactive water to prevent further groundwater pollution. Today, clean groundwater from around the plant flows through the melted reactor and mixes with the contaminated water in the reactors. To prevent ocean pollution, Tepco has to store the contaminated water in reservoirs and treat it, before pumping it back out.
Tepco has warned that decommissioning the Fukushima nuclear plant could take up to 40 years. In early July, the Japanese government notified the evacuated residents of Naraha — a town of 7,400 that lies 20 miles from the nuclear plant — that they would be able return to their homes in September. Naraha has an estimated annual radiation dose of 20 millisieverts — the maximum annual dose allowed for nuclear energy workers in France.
Following the 2011 nuclear disaster, Japan shut down all of its 50 working reactors, which were supplying close to a third of the country's electricity. Forced to turn to other sources of energy, Japan has since become the second largest importer of coal behind China.
Tepco has been heavily criticized for its handling of the Fukushima catastrophe, and three former Tepco executives currently face criminal charges and are due to stand trial soon for "negligence."
In February, the nuclear operator revealed that contaminated water had been leaking into the Pacific ocean. According to French daily Le Monde, Tepco had known about the leak for almost a year before it made the information public.
Japan currently has 48 off-line reactors — a few of which have recently been deemed operable. Pending decisions by local authorities, these reactions could be operational as early as the end of 2015.
Watch the VICE News documentary, "The Worst Internship Ever: Japan's Labor Pains."