Difficult to tell you” on difficult nuclear fuel extraction…Fukushima Daiichi Nuclear Power Plant “Treated water to be released for 30 years”, says TEPCO.

Fukushima Daiichi Nuclear Power Plant’s radioactive treated water was discharged into the sea on Aug. August 24th. The discharge of treated water from the Fukushima Daiichi Nuclear Power Plant began on August 24. In addition to opposition from fishermen, there is also strong opposition from neighboring countries, and China has decided to suspend all imports of Japanese marine products. Some experts have pointed out that there are still places to store the treated water without forcing the release into the ocean.

Melted and solidified nuclear fuel (fuel debris) remains in the reactors of Fukushima Daiichi reactors 1-3. The water used to cool this debris has become contaminated with radioactive materials and is called contaminated water. The amount of contaminated water is increasing as it mixes with groundwater and rainwater, and the water that has had all but tritium removed is stored in tanks as treated water. The amount is 1.34 million tons. The amount of water that has been removed except for tritium has been stored in tanks.

The government has decided to discharge the water into the ocean because it will run out of storage space if the situation continues. According to the plan, at least The plan is to continue the discharge for a long period of time, until at least FY2051. “Prime Minister Kishida has stated that the reason for discharging the treated water into the ocean is that ‘the tanks storing the treated water at the Fukushima Daiichi Nuclear Power Plant are too large.

Prime Minister Kishida said that the reason for releasing the treated water into the ocean is that “the Fukushima Daiichi Nuclear Power Plant has a forest of tanks to store the treated water, and there is no place to proceed with decommissioning the plant. The decommissioning site here means a place to store fuel debris to be removed from the reactors in the future. However, experts are questioning whether it is even possible to remove the debris in the first place.

“It will not be possible to remove the nuclear fuel for 50 years.

The highly radioactive fuel debris is a total of 880 tons of highly radioactive fuel debris in total. It is said that there are 880 tons of highly radioactive fuel debris in total. It is certain that once it is taken out, a storage site will be needed somewhere, but many point out that it cannot be easily removed. Masashi Goto, a former nuclear design engineer at Toshiba Corporation, is one of them.

The debris in reactors Nos. 1 through 3 is currently highly radioactive and stuck to the floor, walls, and other parts of the reactor. TEPCO is trying to remove the debris with robots, but it is not easy, and even the test removal of a few grams of debris is still behind schedule.

There is no hope that full-scale extraction will proceed in the near future. It will not be possible to proceed with full-scale extraction for the next 50 years. It will not be possible to proceed with full-scale debris removal for another 50 years. The argument that we need a storage site when it is almost impossible to remove the debris is not a realistic one from either a technical or scientific standpoint.

If debris removal takes a long time, it is possible to build additional processing water tanks at the planned site where the removed debris will be stored. The government estimates that a temporary storage facility for fuel debris would require a maximum of 60,000 square meters.

In addition, the company has set aside about 40,000 square meters on the north side of the site as a storage area for soil excavated during the construction of a fuel debris storage facility and other facilities, so the total area is about 10,000 square meters. Therefore, a total of approximately 100,000 square meters will be available for use. This means that a total of approximately 100,000 square meters can be used. The current treated water tank area is approximately 23 If both tanks are utilized, there will be no need to discharge the water into the ocean. Mr. Goto explains.

“The current 1,000 ton class tanks and replace them with 100,000-ton class tanks will be built in the available space. The 100,000-ton class tanks will be built in the available space and the treated water will be transferred to them. If we then replace the empty existing tanks with larger ones, the storage capacity will increase dramatically.

Or, the treated water can be mortared to prevent leakage of radioactive materials and buried underground. The half-life of tritium is 12 years and about 3 months, 100 years. In any case, we don’t have to release it into the ocean now,” he said. In any case, there is no need to discharge tritium into the ocean now.

The Chernobyl nuclear power plant, which also suffered a major accident, has not removed any debris.

The reason for the delay is ……

The Chernobyl plant, like the Fukushima Daiichi plant, melted a large amount of debris in its reactor, but instead of removing the debris, a sarcophagus was used to harden the reactor to contain the radioactive materials. The debris was taken out of the reactor in order to prevent radioactive materials from being released into the environment, but it is contradictory to discharge the treated water, which still contains tritium, into the sea,” said Goto.

When we asked TEPCO about the removal of fuel debris, they responded, “The removed fuel debris is temporarily stored in the nuclear power plant.

We are still considering the location and size of the temporary storage site for the removed fuel debris. The reason for the delay in the test removal is that the number of people entering the site has been limited due to the new coronavirus, and the control program for the robotic arm used to remove the debris is being improved so that it can grab the debris accurately.

Full-scale removal will take place after the test removal, but the timing has not yet been determined. We cannot start dismantling the reactor building until the debris removal is completed, so it is difficult to say when that will be.

In the future, 30 years or more. The discharge of treated water into the Pacific Ocean will continue for more than 30 years. If any radioactive materials other than tritium get mixed in during that time, it will inevitably cause a major problem internationally. Japan is now facing a high-risk situation.