The Fukushima disaster at No.1 nuclear power plant raised a new problem to the current working nuclear power plants, which is about how to deal with the used nuclear fuel. By a survey of Asahi Shimbun, among Japan’s nuclear power plants, 70 percent of the total storage capacity of spent nuclear fuel has already been occupied. Among these nuclear power plants, the highest occupied rate is 93 percent in Fukushima No.1 nuclear power plant and the second one is Tokai No.2 nuclear power plant in Ibaraki Prefecture by Japan Atomic Power Company which has an 86 percent usage rate. Once it is fully filled, the nuclear power plant would be useless and cannot operate because the newly wasted used nuclear fuel is not able to be stored. On the top two power plants with highest percentage of storage, they store some of the newly produced waste in the containers and put it into other buildings. These used fuels need to be stored in pools because of the heat and radiation they have. The storage pool in another power plant in Shizuoka Prefecture doubled its nuclear fuel assemblies. Japan is currently aims to build a reprocessing facility for the spent nuclear fuel. However, the plant has to stop because of several technical problems and it is not resumed yet. There is also another intermediate storage which is under planning by TEPCO and Japan Atomic Power in Mutsu, Aomori Prefecture that can accept 5000 tons of used nuclear fuel. However, after the Great East Japan Earthquake, the construction has to stop.
Spent fuel causing headaches for nuclear power plants
After the accident, Tokyo Electric Power plans to rerun the program to reuse water to decrease the temperature of the reactors of Fukushima No.1 nuclear plant. However, the system ran on 27th June after 90 minutes of operation because some water had leaked due to unsecured joint point of pipe. TEPCO said the system was checked on June 12th and the water recirculation system was properly installed at that time. The system could allow sixteen tons of water per hour to be pumped to cool the No.1 to No.3 reactors. The water went through reactors will become radioactive since it was exposed to nuclear power. The water reuse system combines 3 tones of outside water with 13 tones of purified radioactive water per hour. This reduced the need of outside water and helped deal with the radioactive water stored in the power plant. The water purifying system was made by Kurion Inc. of the United States. It is supposed to absorb the radioactive content by minerals. There are also facilities made by French nuclear engineering company that lower the radioactive concentration by chemical agents. Although these equipments can treat contaminated water, polluted salt water was not be able to be treated by the desalination equipment unless the radiation level was less thant 1/10000. Because the equipment is complex, it is fragile and might fail easily. The engineers who worked on the machine did not expect it to be completely no problem either.
TEPCO ready to give crucial water cleaning another go