By Tatsujiro Suzuki,
Technical challenges. The most difficult challenge is, of course, the decommissioning of the Fukushima Daiichi reactors. It would take too long to describe all of the technical challenges of the decommissioning operations, but two recent events are instructive of the overall difficulties.
The first is the dismantlement of the joint exhaust stack for units one and two. This stack stands 120 meters tall and is at risk of collapse because of fractures in its pillars. It was also heavily contaminated by the venting of radioactive gases during the accident
The second technical problem, which is much more serious than the first, is the management of contaminated water. The water is continuously injected into the reactors to cool the fuel debris, and then treated to remove most—though not all—of the radioactive materials. The so-called “treated water” is being stored on site and amounts to about 1.1 million tons, with several hundred tons being added every day. According to TEPCO, the total tank capacity to store treated water will be approximately 1.37 million tons by the end of 2020, but the volume of treated water will exceed storage capacity by 2022. A subcommittee of the Ministry of Economy, Trade, and Industry recommended that the treated water, which still contains tritium, should be released into the sea once the radioactive concentration is below the standard agreed beforehand. The agreed standard between TEPCO and the local fishing industry association is 1,500 becquerels per liter (Bq/l), which is far below the drinking water standard for tritium water of 10,000 Bq/l set by the World Health Organization. An additional condition of release, however, is that all other radioactive substances besides tritium must be removed below a detectable limit or in line with regulatory standards. Unfortunately, in August 2019 news outlets reported that some radioactive materials such as iodine 129 were not completely removed and that their concentration levels were above the regulatory standards.
Most recently, the super typhoon Hagibis hit the eastern part of Japan, which includes Fukushima prefecture and the area affected by the nuclear accident. TEPCO reported irregular readings from sensors monitoring water at the Fukushima Daiichi plant but did not confirm whether any radioactive water leaked into the sea. In addition, according to the Tamura city government, some bulk bags filled with soil collected from decontamination operations were swept into a river during the typhoon on October 12. The bags were among 2,667 that have been temporarily stored at a site in the city. The Ministry of the Environment later confirmed that total of 11 bags were swept away and found downstream. Thankfully, there was no evidence that any of the contaminated soil leaked out. But this wasn’t the first time an incident like this has happened. In September 2015, several hundred bags were swept downstream during flooding caused by tropical storm Etau. The recurring close calls reveal the ongoing vulnerabilities of the Fukushima and associated sites. The contaminated soil will need to be stored for at least 30 years, and the risk of possible leakage remains if a larger and stronger typhoon, or a tsunami, hits the region again.
Socio-political challenges. On September 19, 2019, three former top executives of TEPCO were found not guilty of criminal negligence for their roles in the disaster, which resulted in the death of 44 and the injury of 13 others.
Although the criminal case was highly symbolic, it is not the only legal one involving TEPCO and Fukushima. More than 100,000 evacuees have filed about 30 different civil lawsuits seeking compensation from TEPCO and the government. Several district courts have ruled that TEPCO could have predicted and prevented the nuclear crisis and have awarded millions of dollars in damages to the evacuees.
Lessons not learned. The ongoing technical, economic, and socio-political problems demonstrate that the nuclear power industry and the Japanese government haven’t learned their lesson from the Fukushima accident, which is that transparency is the key to public trust. It is true that the quantity of information about cleanup has increased substantially over the years. But transparency means that the utilities and the government need to disclose information that the public needs, even when it is not favorable to them. One solution, which they have so far been unwilling to accept, would be to establish a truly independent third party to oversee their activities. Lack of such an independent oversight organization is one of the main causes for not taking alternative and possibly better, more appropriate measures over the last eight years.
Read more at An update from Fukushima, and the challenges that remain there