The 1, tanks filled with treated but still radioactive water tower over workers and visitors at the plant. A decision on that recommendation is pending. TEPCO and government officials say tritium, which is not harmful in small amounts, cannot be removed from the water, but all other isotopes selected for treatment can be reduced to safe levels for release.
TEPCO has managed to cut the amount of contaminated water to one-third of what it used to be through a series of measures. In another building, plant workers — about 4, per day now — go through automated security checkpoints and radiation measurements. Because radiation levels have fallen significantly following decontamination, full protection gear is only needed in a few places in the plant, including in and around the melted reactor buildings.
On a recent visit, AP journalists donned partial protective gear to tour a low-radiation area: a helmet, double socks, cotton gloves, surgical masks, goggles and a vest with a personal dosimeter. Full protection gear, which means hazmat coveralls, a full-face mask, a head cover, triple socks and double rubber gloves, was required at a shared storage pool where fuel relocation from the No. TEPCO says it needs to get rid of the water storage tanks to free up space at the plant so workers can build facilities that will be used to study and store melted fuel and other debris.
There are about , tons of solid radioactive waste, including contaminated debris and soil, sludge from water treatment, scrapped tanks and other waste. Local officials and residents say they expect the complex to one day be open space where they can walk freely. Tokyo correspondent Mari Yamaguchi has visited the Fukushima nuclear plant nine times, starting in Photograph: This photo shows tanks in gray, beige and blue storing water that was treated but still radioactive after it was used to cool down spent fuel at the Fukushima Daiichi nuclear power plant in Okuma town, Fukushima prefecture, northeastern Japan, on Saturday, Feb.
Thank you! Please tell us what you liked about it. According to the decommissioning roadmap, Tepco is expected to start retrieving the debris from reactor No. The robotic arm, created in the U. K, that will be used to retrieve fuel debris from reactor No. The U. But with the pandemic forcing RACE to shrink down its research team, it is not clear when the test will be held.
The initial plan was to transfer the robotic arm in the U. An IRID official in charge said it will do its best so that there will be minimal effect on the entire schedule. Significantly high radiation levels inside the reactor No. Even though the robotic device is designed to tolerate a certain level of radiation, engineers still need to control it accurately while racing against time before the device malfunctions under the high radiation.
Moving a couple of centimeters in the wrong direction could be fatal for the mission at hand. Training is essential for this kind of sensitive work.
But with the pandemic, there is no telling when engineers from the U. Inside reactor No. While Tepco plans to use the robotic arm to retrieve fuel debris from the containment vessel, it needs to come up with another way to clear the debris inside the pressure vessel, planning everything from scratch. At present, nothing has been decided. If engineers take out the debris from the bottom of the pressure vessel, the debris itself as well as other parts inside may fall to the bottom of the containment vessel, and that could damage other devices.
Since that could become another headache on its own, some sources believe it is not realistic. If they want to take out the debris from the side or from above the pressure vessel, they need to create a hole in the vessel to put through a device to see what it looks like inside. In order to do that, though, they need to retrieve spent nuclear fuel placed in a pool located at the top of the reactor building. The plan is to start removing the spent fuel rods in reactor No.
At reactor No. Research up to present shows that the inside of the vessel has drastically changed from its original state, with fuel debris tangled up with structural parts piled up to three meters high at the bottom of the containment vessel. Researchers are analyzing how to remove the debris. In March, Tepco revealed a roadmap for decommissioning the Fukushima plant over the next 12 years, with a plan to remove the debris from reactor No. It also laid out a plan to lower the water level for reactor No.
The water level is above the ceiling of the ground floor of the reactor building, which is more than the amount of water at reactors Nos. In order to apply the same tactics used to remove reactor No. Tepco plans to draw out water through the suppression chamber connected to the bottom of the containment vessel.
But at the same time, Tepco needs to inject water to cool the fuel debris, which means it needs to adjust the amount of water injected and drawn out. One of the headaches is that the suppression chamber is filled to the brim with water. That water, specifically 1. But local residents, especially fishermen are opposed to that plan, telling touring reporters on the nine-year anniversary of the disaster that the water release would further damage the already battered reputation of fisheries — where sales remain at only half of what they were before the catastrophe.
According to a government report released earlier this year, one possibility is that technicians could dilute the water to levels below the allowable safety limits, and then release it into the sea in a controlled way. The other is to allow the water to evaporate over the course of several years. The dilemma over what do with the water is part of the complicated aftermath of the 9.
A wall of water destroyed cooling capabilities at the Fukushima nuclear plant and three of its six nuclear reactors melted down, forcing the evacuation of , people. In the days that followed the quake, the Fukushima-Daiichi plant was rocked by hydrogen explosions, which burst through the roofs of the three afflicted reactors, sending radioactive iodine, cesium and other fission by-products belching into the environment.
Millions of liters of water were pumped from the ocean to cool the overheating reactors, cascading contamination into the sea. A clock, found in debris on a beach in Fukushima, stopped at the exact time the March 11, tsunami hit.
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