Today in various cities in Japan have been remember the more than 20,000 people who died in the magnitude 9 earthquake and subsequent tsunami that occurred on March 11, 2011. The commemorations took place at a difficult time for the Japanese government, which is struggling to carry out land reclamation activities nuclear plant in Fukushima, badly damaged by the tsunami 12 years ago. A plan to dump a large amount of radiation-tainted water into the Pacific Ocean has been under discussion for months. For the government, the operation is inevitable, but there are doubts and concerns on the part of various observers about the possible consequences for the environment.
However, the discharge of water at the plant is only one of many remediation activities at the Fukushima nuclear power plant, which will take decades to complete. The Japanese government believes it can complete all operations by 2051, but there are strong doubts about the feasibility of the plan given the large delays accumulated so far.
Recently some reporters from the news agency Associated Press they had the opportunity to visit part of the plant, approaching about thirty tanks used to contain part of the contaminated water. Tokyo Electric Power Company Holdings (TEPCO), the company that manages the plant, hopes to complete the construction of a concrete structure by the spring which will be used to dilute the water, after the necessary decontamination treatments, before releasing it into the ocean through a pipeline that reaches about a kilometer away from the coast. TEPCO will need to obtain approvals from the Japan Nuclear Authority and have its system audited by theInternational Atomic Energy Agency of the United Nations (IAEA).
The 2011 earthquake and tsunami damaged the cooling systems of the Fukushima plant, causing the plant’s reactors 1, 2 and 3 to melt down with a significant loss of radiation. Since then, hundreds of tons of water have been used every day to cool them to prevent the temperature from rising in the reactors: part of the water is reused, but there are legal limits on the levels of contamination and the risks of using more and more water radioactive in the reactors, themselves already damaged. The water is then treated and collected in tanks, which have gradually been built around the plant. By now there are about a thousand that contain treated water, but with levels of radioactivity such that they cannot be released into the environment.
The tanks used to collect the cooling water of the reactors in Fukushima, Japan (AP Photo/Mari Yamaguchi)
According to TEPCO, the levels of radioactivity can be reduced with certain treatments and greater water dilution. However, the procedures will not allow the elimination of tritium (an isotope of hydrogen), but its concentration will be such that it will not cause problems, according to TEPCO. The tritium is cyclically released even from nuclear plants operating normally and at low concentrations it does not usually pose a risk to the environment.
The accumulation of contaminated water was an early problem in Fukushima. In the early stages of the emergency, a lot of it had collected on the concrete base that isolates the reactors from the ground, with contamination of the underlying soil. TEPCO engineers explained ad Associated Press that the emptying is necessary to start the dismantling of the tanks, in order to have the necessary space to proceed with the other reclamation activities of the nuclear power plant. The reservoirs are at 96 percent of their capacity and at current rates will be full by next fall, with a total of 1.37 million tons of water.
The technicians say that there are also other safety reasons that make it necessary to empty the tanks. In the event of another earthquake or tsunami, reservoirs could be damaged and large amounts of untreated water could end up in the ocean. TEPCO’s procedure calls for the spill to be gradual and controlled, with a release off the coast to further reduce risks and encourage greater dilution of wastewater.
However, nearby fishing communities do not feel reassured by TEPCO and the government’s claims, nor are countries that have coastlines that could be affected by the operation, such as China and South Korea. Fishermen say the fish fished in waters known to be where Fukushima’s sewage ended up could go unsold, ruining their business, and they fear some areas could become less fishy due to the spill.
In recent months TEPCO has organized some demonstration tests, making fish and molluscs live in a tank with normal ocean water and other specimens of the same species in a tank containing water from the nuclear plant and at the right degree of dilution. The level of radioactivity detected in the fish and shellfish increased slightly while they were in the contaminated water, but then returned to normal levels after a few days in the ocean water. According to the technicians, this confirms the data on the negligible effects of tritium on marine fauna.
A TEPCO manager shows some of the tanks used for fish and shellfish testing (AP Photo/Mari Yamaguchi)
The Japanese government has foreseen the allocation of almost 600 million euros to help the fish industry in the Fukushima area, for the “reputational damage” that could result from the payment. The words have been carefully calibrated so as not to give the impression that the funds were allocated out of concern for possible environmental damage.
The levels of radioactivity and the effects of the spill will be kept under control for tens of years, in parallel with the other decommissioning activities of the nuclear plant which are expected to last for at least 30-40 years. However, there are doubts about the procedures chosen for the checks and for the involvement of the IAEA, with requests from various environmental associations for further checks by independent institutions.
Twelve years after the serious damage to the nuclear power plant, however, there is still a lot of work to do, with all the difficulties to get close to the still highly radioactive reactors inside. At the beginning of the year, a remotely controlled robot managed to recover a few grams of the material contained in reactor 1, a very small part of the approximately 880 tons of debris found in the three reactors. The first attempts to extract part of it from reactor 2 will be organized in the coming months, an activity that should have started two years ago. Operations around reactor 1 will not start until 2027, almost ten years behind schedule.
Despite numerous postponements, the Japanese government continues to maintain the goal of 30-40 years after the earthquake to complete the dismantling of the Fukushima plant. However, the declaration is generic and it is not yet clear what is meant by the purpose of the activities.