Container containing radioactive waste collapses, Fukushima Daiichi Nuclear Power Plant, storage method issues come to light

March 20, 2022
　A series of radioactive waste containers stored outdoors at TEPCO’s Fukushima Daiichi Nuclear Power Plant were toppled and tilted by an earthquake late at night on March 16. Similar damage occurred during the Fukushima earthquake in February of last year, highlighting once again the challenges of storage methods. TEPCO is continuing to take stopgap measures until the waste is transferred to an indoor storage facility, but the Nuclear Regulation Authority is ready to request that more aggressive measures be taken.

Container containing used protective clothing that was toppled by the earthquake. Radiation levels were very low and had no impact on the surrounding environment (courtesy of TEPCO).

Four units damaged, contents outside

　As of January 19, there were a total of eight 1 meter square containers known to have toppled over. Four of them were damaged and their contents were exposed. All of them contained low-dose used protective clothing. Several other containers in two other groups of containers covered with sheets also toppled over.

　Seventy-seven containers were tilted by the earthquake last February, and a total of 12 units toppled over at two locations. Some of the containers were four-tiered, and the shaking of the earthquake broke the connecting fittings, etc. Although the containers were re-stacked two or three-tiered and the bottom foundations were reinforced, the damage could not be prevented this time either.

　In March of last year, one corroded waste container leaked a high dose of radioactive material onto the ground, which flowed into the port through a drainage channel. In July of the same year, rainwater that had entered a container for contaminated soil overflowed from inside the container.

　A total of 85,500 outdoor waste containers are now in use. TEPCO inspected a total of 5,338 containers with a certain amount of surface radiation, and found that a total of 646 containers had corrosion or damage. Damage was found and emergency repairs were made. The risks associated with emergency evacuation-like waste management after the accident have become apparent.

A three-tiered container that was displaced by the earthquake. At this point, there is no danger of the container toppling over (courtesy of the Nuclear Regulation Authority).

Reduce risk outside the building.

　The Regulatory Commission is becoming increasingly aware of the problem. At a regular meeting on February 2, Chairman Toyoshi Sarada mentioned the option of temporarily storing outdoor waste underground by covering it with soil. He stated that it would be difficult to gain the understanding of the local community, but considering the risk of leakage, it would be undesirable to leave the waste above ground.

　TEPCO has announced a policy to remove all the contents of the containers to the storage facility by FY2028 to eliminate the outdoor storage, but there is no guarantee that an earthquake, typhoon, or other large-scale natural disaster will occur before the work is completed. There is no guarantee that this will not happen. If trouble occurs, it will lead to reputational damage to the local community.

　Shinsuke Yamanaka, a member of the Regulatory Commission who inspected a group of containers at the No. 1 nuclear power plant on March 17, touched on the issue of outdoor waste in an interview after the visit and stressed, “It is important to talk about the inside of the reactor buildings, but right now I want you to prioritize risk reduction outside the buildings. He also expressed his desire to ask TEPCO to come up with concrete measures.