Construction projects surge at Fukushima nuclear plant despite decommissioning progress
April 4, 2022
OKUMA, Fukushima — The site of the Fukushima Daiichi Nuclear Power Station continues to host new construction projects some 11 years after the disaster triggered by the 2011 Great East Japan Earthquake and tsunamis.
This Mainichi Shimbun reporter had the opportunity to visit the plant for the first time in seven and a half years, and reflect on why new facilities continue to appear even as the plant moves toward decommissioning.
The last time I visited the Fukushima Nuclear Power Station, high radiation levels relegated me to observing the site from inside a bus, but on my Feb. 26 visit I was able to enter the outdoor area near the reactor buildings of Units 1 to 4, where the incidents occurred. Progress has been made toward decontaminating radioactive materials scattered in the meltdown, and 96% of the premises can reportedly now be walked around in normal work clothes.
While decommissioning seems to be advancing, various facilities have been newly constructed, and the issue of water remains. A rising number of tanks store treated water contaminated after it was pumped to cool fuel debris that melted down in the accident, as well as groundwater and rainwater that flowed into the buildings. Inside the tanks, the contaminated water is made to reach a radioactive concentration below regulation levels.
On the seventh floor of a building located near the site’s entrance, a Tokyo Electric Power Co. Holdings Inc. (TEPCO) representative gave me an outline of the entire facility. I could see two large cranes on the ocean side around Units 1 to 4, and another large crane and framework structure on the mountain side. When I asked about it, the representative told me the frame was being assembled in a remote location to reduce worker radiation exposure. But it wasn’t a facility being dismantled; it’s a cover measuring 66 meters long, 56 meters wide, and 68 meters high that will wrap around Unit 1.
The hydrogen explosion in Unit 1 blew the building’s roof off, and 392 pieces of nuclear fuel remain in its spent fuel pool near the ceiling. Their removal is scheduled to start in fiscal 2027 to 2028. For this to happen, the surrounding debris must be removed, and the cover’s installation will help prevent the work dispersing radioactive dust.
Ground improvements works were progressing on the neighboring Unit 2’s south side. There, a working platform to remove 615 pieces of nuclear fuel from Unit 2 will be built, with its start slated for fiscal 2024 to 2026.
The buildings for Units 1 through 4 were damaged and contaminated, so different structures, such as platforms and covers, had to be built to remove nuclear fuel from the pools. Particularly conspicuous was the thick steel frame of the Unit 4 facility, from which fuel was completely removed in 2014. Although 53 meters high, it surprisingly uses about the same amount of steel as the 333-meter-high Tokyo Tower. Since the nuclear fuel is being removed in order, new construction work continues in reactor buildings’ vicinities.
The Japanese government decided in April 2021 to release into the ocean treated water stored in at least 1,000 tanks. The decision is not unrelated to the boom in construction.
At the Nuclear Regulation Authority’s March 1 review meeting on treated water discharge, TEPCO explained the offshore release was needed “to safely and steadily remove fuel debris and spent nuclear fuel.” The company listed at least 10 facilities earmarked for future construction. Put another way, the tanks need to be removed to provide land for these facilities.
Related construction work had already started at the seashore, where workers dug vertical holes to contain treated water before its release. After the implementation plan’s approval, undersea tunnel construction and other necessary work to release the water 1 km offshore will also begin.
Meanwhile, some broken cranes and damaged buildings have been left on site without being dismantled. The representative told the Mainichi Shimbun this was partly due to them trying to keep the solid waste processing volume low.
Also underway is construction of facilities to handle ever-increasing solid waste amounts. The representative said a white building I spotted in the site’s northwest side was the volume reduction facility, and that building work is going ahead for a solid waste storage facility in front of it.
The volume reduction facility scheduled for completion in March 2023 will use crushing and other methods to reduce concrete and metal debris volumes. Although nine storage buildings already exist, a 10th will soon be constructed. Nearby was also a new incineration facility for burning logged trees. TEPCO estimates solid waste generated will reach a volume of 794,000 cubic meters by March 2033, and that there will continue to be more related facilities.
Fuel debris removal will begin at the end of 2022. In the future, facilities to hold fuel debris and to store and reduce volumes of solid waste with high doses of radiation generated by the work will also be needed.
Each year creates new tasks that generate more waste, and the facilities to accommodate it. These buildings are also destined to eventually become solid waste. While this cycle continues, a final disposal method for the waste is undetermined. The government’s and TEPCO’s timetable says 20 to 30 years of plant decommissioning remain. But on site, where new construction projects continue to appear, a clear picture of when decommissioning will finish has yet to emerge.
(Japanese original by Takuya Yoshida, Science & Environment News Department)
Fate of Fukushima reactor cleanup uncertain after 11 years
March 13, 2022
OKUMA, Japan—Eleven years after the Fukushima Daiichi nuclear power plant was ravaged by a meltdown following a massive earthquake and tsunami, the plant now looks like a sprawling construction site. Most of the radioactive debris blasted by the hydrogen explosions has been cleared and the torn buildings have been fixed.
During a recent visit by journalists from The Associated Press to see firsthand the cleanup of one of the world’s worst nuclear meltdowns, helmeted men wore regular work clothes and surgical masks, instead of previously required hazmat coveralls and full-face masks, as they dug near a recently reinforced oceanside seawall.
Workers were preparing for the planned construction of an Olympic pool-sized shaft for use in a highly controversial plan set to begin in the spring of 2023 to gradually get rid of treated radioactive water—now exceeding 1.3 million tons stored in 1,000 tanks—so officials can make room for other facilities needed for the plant‘s decommissioning.
Despite the progress, massive amounts of radioactive melted fuel remain inside of the reactors. There‘s worry about the fuel because so much about its condition is still unknown, even to officials in charge of the cleanup.
Nearly 900 tons of melted nuclear fuel remain inside the three damaged reactors, and its removal is an unprecedented challenge involving 10 times the amount of damaged fuel removed in the Three Mile Island cleanup following its 1979 partial core melt.
The government has set a decommissioning roadmap aiming for completion in 29 years.
The challenge of removing melted fuel from the reactors is so daunting that some experts now say that setting a completion target is impossible, especially as officials still don‘t have any idea about where to store the waste.
Nuclear Regulation Authority Chairman Toyoshi Fuketa said recently that extra time would be needed to determine where and how the highly radioactive waste removed from the reactors should be stored.
Japan has no final storage plans even for the highly radioactive waste that comes out of normal reactors.
Twenty-four of the country‘s 60 reactors are designated for decommissioning, mostly because of the high cost needed to meet safety standards set up in the wake of the Fukushima disaster.
On March 11, 2011, a magnitude 9.0 earthquake caused a tsunami 17 meters (56 feet) high that slammed into the coastal plant, destroying its power supply and cooling systems, causing reactors No. 1, 2 and 3 to melt and spewing massive amounts of radiation.
Three other reactors were offline and survived, though a fourth building suffered hydrogen explosions.
The spreading radiation caused some 160,000 residents to evacuate. Parts of the surrounding neighborhood are still uninhabitable.
The melted cores in Units 1, 2 and 3 largely fell to the bottom of their primary containment vessels, together with control rods and other equipment, some possibly penetrating or mixing with the concrete foundation, making the cleanup extremely difficult.
Probes of the melted fuel must rely on remote-controlled robots carrying equipment such as cameras and dosimeters—which measure radiation—because radiation levels in those areas are still fatally high for humans.
In February, a remote-operated submersible robot entered the Unit 1 primary containment vessel, its first internal probe since a failed 2017 attempt. It captured limited images of what are believed to be mounds of melted fuel rising from the concrete floor.
Probes have moved ahead at Unit 2, where Tokyo Electric Power Co. (Tepco) plans to send in an extendable robotic arm later this year to collect melted fuel samples.
Tepco Chief Decommissioning Officer Akira Ono said in a recent online interview that robotic probes at Unit 1 and 2 this year are a major “step forward” in the decades-long cleanup.
11 years later, Fukushima still faces a long road to full recovery
March 11, 2022
Eleven years after a broad swath of the northeastern Tohoku region was devastated by the Great East Japan Earthquake and tsunami, the government is stressing the progress made in the recovery and reconstruction of disaster-hit areas.
It points out, for example, that its plan to relocate 18,000 houses to areas of high ground for residential land development has been achieved. It also says 98 percent of the local seafood processing facilities have resumed operations in an encouraging sign of recovery of one of the mainstay industries in the region.
But the actual picture is less sunny with the process of recovery and reconstruction only halfway through for most local industries and people’s livelihoods. Local fish hauls are still around 70-80 percent of the pre-disaster levels in Miyagi and Iwate prefectures.
A survey by the Tohoku Bureau of Economy, Trade and Industry found that about 45 percent of affected companies have yet to return to the staffing levels before that day 11 years ago.
DISTRUST OVER FUKUSHIMA CONTAMINATED WATER
In particular, Fukushima Prefecture, where the catastrophic accident broke out at Tokyo Electric Power Co.’s Fukushima No. 1 nuclear power plant, is struggling to recover what it lost in the disaster.
Coastal fishing catches last year were only 20 percent of pre-disaster figures. Fukushima’s hardships will be further compounded by the scheduled start in spring next year of TEPCO’s plans to release treated radioactive water from the crippled nuclear plant into the Pacific Ocean.
Underground water that keeps flowing into the melted reactors is generating a steadily increasing volume of “treated water,” or water currently stored in tanks installed within the compound after being treated with special equipment to eliminate most of the highly radioactive materials.
The government emphasizes that it decided to discharge the water into the sea after explaining meticulously to local communities that scientifically the water poses no health hazard. But the fisheries associations in both Miyagi and Ibaraki prefectures as well as in Fukushima have voiced opposition to the step.
“The decision was made in Tokyo and has been imposed on us,” fumes Ayanori Sato, 31, a Sakhalin surf clam fisherman in the Yotsukura district of Iwaki, a city in Fukushima Prefecture.
In Yotsukura, local fishermen restarted Sakhalin surf clam fishing three years after the nuclear disaster. Since four years ago, the district has been holding Sakhalin surf clam festivals once or twice a month as part of its efforts to dispel unfounded negative rumors about the safety of locally caught clams.
The government and TEPCO have pledged to provide proper compensation if the release of treated water breeds rumors that damage local industries.
A recent Supreme Court ruling on a damages lawsuit filed by people forced to evacuate from their homes due to the Fukushima disaster has increased the distrust of the government and the utility among victims.
The ruling confirmed that the compensation standards set by the government’s interim guidelines are not sufficient. For Sato, who thinks of fishing as his lifelong job, money is not enough to compensate for what he has lost.
The release of treated water is expected to continue for 30 years or so. The government and TEPCO should establish a system to monitor the effects on the environment and locally caught seafood during the period.
There can be no real progress on this matter unless the government and the utility actively disclose information to win the understanding of local communities.
NO PROSPECT FOR MANY EVACUEES TO RETURN HOME
In Fukushima Prefecture, there remains some 340 square kilometers of land where the evacuation order is still in place, areas near the crippled plant with high levels of radiation, known as “kitaku konnan kuiki” (difficult-to-return zone).
The order is set to be lifted this spring in certain parts of the zone designated as reconstruction priority areas eligible for preferential policy support to help improve the living environment, such as intensive decontamination and infrastructure development efforts.
In the town of Futaba, home to the stricken plant and the only municipality in the prefecture that is still covered entirely by the evacuation order, local residents will be allowed to return home for the first time since the accident, possibly in June.
On March 4, a group of 12 workers, including TEPCO group company employees, were carrying 20 tatami mats, chests of drawers and other items placed on them out of the house of Kiyotaka Iwamoto, 74, located close to Futaba Station.
Although the household goods seemed to be still usable, they had to be replaced to lower the radiation levels in the room.
Iwamoto is hoping that the work to repair his home will be completed by summer. But he is expecting to have to shuttle between his home in Futaba and his evacuation site in the city of Nasushiobara in Tochigi Prefecture for the time being.
By the end of February, some 20 local households applied for permission to stay in special facilities within the town to prepare for returning to their homes.
There is no family preparing to return near Iwamoto’s home. He is also concerned about the fact that there is no facility within the town that offers rehabilitation programs for his 71-year-old wife, who suffered a subarachnoid hemorrhage after the disaster.
These reconstruction priority areas constitute only 8 percent of the difficult-to-return zone. The government has repeatedly said it will decontaminate the land and houses of local residents who want to return to their homes so that the order can be lifted for the entire zone by the end of the 2020s. But it has yet to offer any specific plan to achieve this goal, keeping the outlook uncertain.
Despite all these problems plaguing affected areas, the government has tried to paint a rosy picture of Fukushima’s future in its “Fukushima Innovation Coast Framework,” a policy initiative to nurture new high-tech industries in such areas as robotics and hydrogen energy.
Goals are important for efforts to rebuild disaster-hit areas. But promoting such an unrealistic dream does not lead to any progress in key goals. The first step in rebuilding ravaged communities in Fukushima should be mapping out down-to-earth visions for the future of the communities based on tough-minded assessments of the reality of Fukushima.
DEVELOP CONVINCING PLANS TO DECOMMISSION THE REACTORS
At the end of January, a robot arm designed to remove melted nuclear fuel debris at the bottoms of ruined reactors at the plant arrived in Fukushima. A trial run of the machine has started for use at the No. 2 reactor.
This is, however, only a small step in the long and complicated clean-up process. There are an estimated 880 tons of radioactive debris at the bottoms of the Nos. 1-3 reactors. Nobody knows, however, how the debris is scattered about and in what form.
The government has already dropped the goal of removing the debris in 20-25 years, included in the road map for decommissioning the reactors published in December 2011. But the goal of completing the decommissioning process in 30-40 years has been kept unchanged.
One big challenge is finding a location for the final disposal of contaminated soil and waste temporarily stored in Futaba and Okuma, where the plant is located. The completion of the work to deal with the consequences of the accident, which is far more difficult than the ordinary decommissioning process and requires different approaches, is vital for progress in the reconstruction of ravaged communities.
But the government has not offered any clear image of this future nor any reliable estimate of the total cost. While the government has estimated the total cost at 22 trillion yen ($189.15 billion), including the compensation to be paid to victims, one research institute has pegged it at 35 trillion to 80 trillion yen.
The government needs to lay out clear and concrete visions for the ultimate state of the Fukushima No. 1 plant and the process of achieving that state while subjecting the visions to Diet scrutiny. Without such visions, it will remain difficult to clear up the dark cloud of uncertainty hanging over Fukushima’s future.
It is, of course, impossible to find a quick solution to the challenge. The long road to Fukushima reconstruction is strewn with obstacles that have to be overcome one by one.
11 years later, fate of Fukushima reactor cleanup uncertain
By Mari Yamaguchi, March 11, 2022
OKUMA, Japan — Eleven years after the Fukushima Daiichi nuclear power plant was ravaged by a meltdown following a massive earthquake and tsunami, the plant now looks like a sprawling construction site. Most of the radioactive debris blasted by the hydrogen explosions has been cleared and the torn buildings have been fixed.
During a recent visit by journalists from The Associated Press to see firsthand the cleanup of one of the world’s worst nuclear meltdowns, helmeted men wore regular work clothes and surgical masks, instead of previously required hazmat coveralls and full-face masks, as they dug near a recently reinforced oceanside seawall.
Workers were preparing for the planned construction of an Olympic pool-sized shaft for use in a highly controversial plan set to begin in the spring of 2023 to gradually get rid of treated radioactive water — now exceeding 1.3 million tons stored in 1,000 tanks — so officials can make room for other facilities needed for the plant’s decommissioning.
Despite the progress, massive amounts of radioactive melted fuel remain inside of the reactors. There’s worry about the fuel because so much about its condition is still unknown, even to officials in charge of the cleanup.
Nearly 900 tons of melted nuclear fuel remain inside the three damaged reactors, and its removal is an unprecedented challenge involving 10 times the amount of damaged fuel removed in the Three Mile Island cleanup following its 1979 partial core melt.
The government has set a decommissioning roadmap aiming for completion in 29 years.
The challenge of removing melted fuel from the reactors is so daunting that some experts now say that setting a completion target is impossible, especially as officials still don’t have any idea about where to store the waste.
Nuclear Regulation Authority Chairman Toyoshi Fuketa said recently that extra time would be needed to determine where and how the highly radioactive waste removed from the reactors should be stored.
Japan has no final storage plans even for the highly radioactive waste that comes out of normal reactors. Twenty-four of the country’s 60 reactors are designated for decommissioning, mostly because of the high cost needed to meet safety standards set up in the wake of the Fukushima disaster.
On March 11, 2011, a magnitude 9.0 earthquake caused a tsunami 17 meters (56 feet) high that slammed into the coastal plant, destroying its power supply and cooling systems, causing reactors No. 1, 2 and 3 to melt and spewing massive amounts of radiation. Three other reactors were offline and survived, though a fourth building suffered hydrogen explosions.
The spreading radiation caused some 160,000 residents to evacuate. Parts of the surrounding neighborhood are still uninhabitable.
The melted cores in Units 1, 2 and 3 largely fell to the bottom of their primary containment vessels, together with control rods and other equipment, some possibly penetrating or mixing with the concrete foundation, making the cleanup extremely difficult.
Probes of the melted fuel must rely on remote-controlled robots carrying equipment such as cameras and dosimeters — which measure radiation — because radiation levels in those areas are still fatally high for humans.
In February, a remote-operated submersible robot entered the Unit 1 primary containment vessel, its first internal probe since a failed 2017 attempt. It captured limited images of what are believed to be mounds of melted fuel rising from the concrete floor.
Probes have moved ahead at Unit 2, where TEPCO plans to send in an extendable robotic arm later this year to collect melted fuel samples.
TEPCO Chief Decommissioning Officer Akira Ono said in a recent online interview that robotic probes at Unit 1 and 2 this year are a major “step forward” in the decades-long cleanup.
“It’s like we have finally come to the starting line,” Ono said. “Before, we didn’t even know which way we were supposed to go.”
Ono said the Unit 2 melted fuel test removal will start from a granule or two, all of which will be sent for lab analysis, meaning a storage facility won’t be necessary until larger amounts are hauled out. Even a tiny amount would provide valuable data for research and development of fuel and debris removal technology for all three reactors, he said.
Hideyuki Ban, the co-founder of the Citizens’ Nuclear Information Center who previously served on government nuclear safety panels, proposes the underground burial of solidified treated water for stable long-term storage, while entombing the three reactors for several decades — like Chernobyl — and waiting for radioactivity to decrease for better safety and access for workers instead of rushing the cleanup.
Since the disaster, contaminated cooling water has constantly escaped from the damaged primary containment vessels into the reactor building basements, where it mixes with groundwater and rainwater that seep in.
The water is pumped up and treated, partly recycled as cooling water, with the remainder stored in 1,000 huge tanks crowding the plant. The tanks will be full at 1.37 million tons by next spring, TEPCO says.
The government has announced plans to release the water after treatment and dilution to well below the legally releasable levels through a planned undersea tunnel at a site about 1 kilometer offshore. The plan has faced fierce opposition from local residents, especially fishermen concerned about further damage to the area’s reputation.
TEPCO and government officials say tritium, which is not harmful in small amounts, is inseparable from the water, but all other 63 radioactive isotopes selected for treatment ‘can be reduced to safe levels’, tested and further diluted by seawater before release.
Scientists say the health impact from consuming tritium through the food chain could be greater than drinking it in water, and further studies are needed.
At one of the water treatment facilities where radiation levels are much higher, a team of workers in full protective gear handled a container filled with highly radioactive slurry. It had been filtered from the contaminated water that’s been continuously leaking from the damaged reactors and pumped up from their basements since the disaster. Large amounts of slurry and solid radioactive waste also accumulate in the plant.
Radiation levels have fallen significantly after decontamination since the disaster, and full protection gear is only needed in limited areas, including in and around the reactor buildings.
On a recent visit, AP journalists used cotton gloves, goggles, a head cover and surgical masks to tour low-radiation areas.
Additional protection, including hazmat coveralls and double rubber gloves, was required when the journalists entered the Unit 5 primary containment vessel and stood on the grating of the pedestal, a structure beneath the defueled core, where officials explained the concept of using robotic probes in No. 1 and 2 reactors.
TEPCO has emptied spent fuel from the No. 3 and No. 4 reactor pools, but removal at the No. 1 and 2 reactors has been delayed several years because of high radiation and contaminated debris, posing concerns of a spent fuel meltdown in case another major quake caused water loss and overheating.
Futaba Mayor Shiro Izawa says the Fukushima Daiichi plant must be safely and fully decommissioned “to make our hometown a safe and livable place again.” Izawa said he wants the government to “wipe out the (region’s) negative image” by tackling the safe cleanup, which is a prerequisite for the town’s reconstruction.
Fukushima Daiichi Nuclear Power Plant Decommissioning: “It is Impossible to Foresee the End Date” says the Nuclear Regulation Commission
March 2, 2022
Nuclear Regulatory Commission Chairman Toyoshi Sarada said he believes it is impossible to predict when the decommissioning of the Fukushima Daiichi Nuclear Power Plant will be completed.
Nuclear Regulation Authority Chairman Toyoshi Sarada: “I think it is technically impossible to determine a realistic number of years that we can promise to various parties, for example.
At the press conference, Chairman Saroda stated that he believes it is virtually impossible to set a time limit on when the fuel debris in Fukushima Daiichi reactors Nos. 1 through 3 can be cleaned up.
He also recognized that it is technically impossible to give the people of Fukushima and other prefectures a fixed number of years until the plant is decommissioned.
The government and TEPCO are still aiming for a maximum of 29 years to decommission the reactors amidst difficulties in removing debris and other issues.
Online Tour by Reconstruction Agency to Consider Decommissioning of TEPCO’s Fukushima Daiichi Nuclear Power Plant
2022/02/20
On February 20, an online tour was held at the Tokyo Electric Power Company’s Nuclear Decommissioning Museum in Tomioka Town, Fukushima Prefecture, to have people from inside and outside of the prefecture think about the decommissioning of TEPCO’s Fukushima Daiichi Nuclear Power Plant. The speakers voiced the need for greater transparency in the dissemination of information about the Fukushima Daiichi Nuclear Power Plant.
Prof. Nobuhisa Murao of Kwansei Gakuin University, who appeared as a commentator, said that it was important to ensure the transparency of decommissioning work and pointed out that “even small accidents should be made public immediately without hiding them. Masato Kino, director general of the Agency for Natural Resources and Energy of the Ministry of Economy, Trade and Industry, said, “It is important to disclose information on both good and inconvenient matters.
Idol Ayaka Wada, who visited the Fukushima Daiichi Nuclear Power Plant last December, also made an appearance. She said, “I learned that it will take a long time to decommission the plant. Some of the participants suggested that the younger generation should be encouraged to visit the disaster area.
The online tour was organized by the Reconstruction Agency. The online tour was sponsored by the Reconstruction Agency and distributed nationwide via the video-sharing website YouTube. Mr. Kino explained the latest developments in the removal of molten nuclear fuel (debris), measures for contaminated and treated water, and improvements in the working environment. He accepted questions from the participants and exchanged opinions with them.
https://www.minpo.jp/news/moredetail/2022022094602?fbclid=IwAR2npqJ8B2NtHQQMh4O5Hq49pI1lWS9cLCb_ImXblfhX8idUhHAs4eu0nIA
Zero Contaminated Water” and “Dismantling of Reactor Buildings” Missing from the Plan: The Final Form of Decommissioning the TEPCO’s Fukushima Daiichi Nuclear Power Plant
February 11, 2022
On March 11, it will be 11 years since the accident at TEPCO’s Fukushima Daiichi Nuclear Power Plant occurred. During this time, two goals have disappeared from the decommissioning plans of TEPCO and the government. During this time, two goals have disappeared from the decommissioning plans of TEPCO and the government: “zero generation of contaminated water” and “dismantling of reactor buildings. The core of decommissioning has been lost, and the goal of convergence work has yet to be drawn. (Kenta Onozawa)
Unable to stop inflow of groundwater as source of contamination
We want to proceed according to the schedule. We want to proceed as scheduled,” Akira Ono, chief executive officer of TEPCO’s Fukushima No. 1 Decommissioning Promotion Company, stressed at a press conference on January 27. The Nuclear Regulation Authority’s review of the plant’s facilities is scheduled to be conducted once a week, and is expected to be completed by the end of March.
In its initial decommissioning plan, TEPCO had set a goal of “zero generation of contaminated water. However, this goal disappeared when the plan was revised in 2019. Although the amount of contaminated water has been reduced to about one-third of what it was at the time of the accident, it is not known how the large amount of groundwater is flowing into the reactor buildings, the source of the contamination.
The frozen soil barrier, which was introduced to stop the inflow of groundwater, has not been proven to be effective. TEPCO did not respond to the request from the Regulatory Commission to show a direction to stop the water in the building, and continued to emphasize that the tanks would be full next spring, and the government decided to release the water into the ocean.
Once the release of treated water begins, there is no need for TEPCO and the government to hastily revive the goal of “zero contaminated water” because even if contaminated water continues to be generated, it can be purified and treated before being released. However, as long as contaminated water is not reduced to zero, the process of purification, storage, and release will continue endlessly.
Nuclear fuel removal technology and storage also face a difficult road.
What is even more unclear is what to do with the melted down nuclear fuel (debris) and the reactor building where it remains.
In a survey of the interior of the containment vessel of the Unit 1 reactor, a large amount of molten debris, which appeared to have solidified, was seen at the bottom of the vessel photographed by an underwater robot on August 9. It is likely to be debris, as it is close to the pressure vessel where the nuclear fuel was located.
Of the three reactors that suffered meltdowns, Unit 1 was the only one where the accumulation of debris could not be confirmed, and the detailed investigation using six different robots finally showed signs of progress.
However, the road to debris recovery is long and arduous. At the Unit 2 reactor, which will be the first to take out debris, trial collection is planned to start within 2010, but it will be limited to a few grams each by robots.
The total amount of debris, which is high-dose radioactive waste, is estimated to be 880 tons for the three reactors. The total amount of debris, or high-dose radioactive waste, is estimated to be 880 tons for the three reactors, and even if it takes 30 years to remove the debris, it will not be finished until 80 kilograms are removed each day. We do not have the technology to remove the entire amount of waste, nor do we have a concrete plan for how to store it in an environment where high radiation levels are a hindrance.
Decommissioning usually means clearing the land…
TEPCO and the government will maintain the plan to finish decommissioning the plant in 41-51 years, but the original plan to dismantle the reactor buildings disappeared in 2013. Decommissioning refers to the clearing of the land for normal nuclear power plants, but what is the status of Fukushima Daiichi?
The final decision on what to do will be made in consultation with the local government. Akira Ono, who is in charge of TEPCO’s decommissioning, once answered at a press conference. TEPCO and the government have yet to even consider the final form of decommissioning, with only the end date unchanged.
https://www.tokyo-np.co.jp/article/159484?rct=national&fbclid=IwAR2VVYtQA4iLWpvxMz_YXqCWzee3_uXLmJmR6yUaDYIrKJDdeezIIcr-lUE
Fukushima Daiichi Nuclear Power Plant “debris” storage method to be reconsidered – Chairman of the Regulatory Commission, Mr. Sarada
February 2, 2022
The chairman of the Nuclear Regulation Authority (NRA), Mr. Toyoshi Sarada, has asked Tokyo Electric Power Company (TEPCO) to reconsider the storage method of concrete debris with a very small amount of radioactive materials from the Fukushima Daiichi Nuclear Power Plant, with a view to temporarily burying it underground.
It has been 11 years since the accident at the Fukushima Daiichi Nuclear Power Plant occurred in March 2011. The decommissioning of the nuclear power plant involves the removal of nuclear fuel that has cooled down after melting down. The biggest challenge is to remove the fuel debris. On the other hand, the disposal of low-level radioactive waste, which is generated in large quantities every day at the decommissioning site, is also a major issue.
As a result of the hydrogen explosions in the three reactor buildings, concrete fragments were scattered.
At a meeting of the Nuclear Regulation Authority held on the 2nd, Mr. Sarada said, “Even if we assume that the waste will be transferred in the future, there are some areas where it would be much more advantageous to bury and store the waste,” and expressed his desire to ask TEPCO to reconsider the storage method with a view to temporarily burying it underground.
The amount of waste from the decommissioning of the nuclear power plant is increasing, but the management at the site is not up to the task, so a realistic storage method must be considered with an eye to the future, he said.
Can reactor fuel debris be safely removed from Fukushima Daiichi?
January 25, 2022
Source: University of Helsinki
Decommissioning and clean-up are ongoing at the Fukushima Daiichi Nuclear Power Plant (FDNPP); however, many difficult problems remain unaddressed. Chief amongst these problems is the retrieval and management of fuel debris.
Decommissioning and clean-up are ongoing at the Fukushima Daiichi Nuclear Power Plant (FDNPP); however, many difficult problems remain unaddressed. Chief amongst these problems is the retrieval and management of fuel debris. Fuel debris is the name given to the solidified mixture of melted nuclear fuel and other materials that now lie at the base of each of the damaged reactors (reactor Units 1 — 3). This material is highly radioactive and it has potential to generate enough neutrons to trigger successive nuclear fission reactions (uranium-235 breaks into two elements after capturing neutrons, emitting enormous amounts of energy, radiation, and more neutrons). Successive fission reactions would present a serious safety and material management risk.
One of the materials in nuclear reactors that can lower the number of neutrons interacting with uranium-235 is boron carbide (B4C). This was used as the control rod material in the FDNPP reactors, and it may now remain within the fuel debris. If so, it may limit fission events within the fuel debris.
Can the fuel debris be safely removed?
On March 11th 2011, the control rods were inserted into the FDNPP reactors to stop the fission reactions immediately after the earthquake, but the later tsunami destroyed the reactor cooling systems. Fuel temperatures soon became high enough (>2000 °C) to cause reactor meltdowns. Currently, the fuel debris material from each reactor is cooled and stable; however, careful assessment of these materials, including not only their inventories of radioactive elements but as well their boron content, a neutron absorber, is needed to ascertain if successive fission reactions and associated neutron flux could occur in the fuel debris during its removal. Many important questions remain: was boron from the control rods lost at high temperature during the meltdown? If so, does enough boron remain in the fuel debris to limit successive fission reactions within this material? These questions must be answered to support safe decommissioning.
Study shows direct evidence of volatilization of control rods during the accident.
Despite the importance of this topic, the state and stability of the FDNPP control rod material has remained unknown until now. However, work just published in the Journal of Hazardous Materials now provides vital evidence that indicates that most of the control rod boron remains in at least two of the damaged FDNPP reactors (Units 2 and/or 3).
The study was an international effort involving scientists from Japan, Finland, France, and the USA. Dr. Satoshi Utsunomiya and graduate student Kazuki Fueda of Kyushu University led the study. Using electron microscopy and secondary ion mass spectrometry (SIMS), the team has been able to report the first-ever measurements of boron and lithium chemistry from radioactive Cs-rich microparticles (CsMPs). CsMPs formed inside FDNPP reactor units 2 and/or 3 during the meltdowns. These microscopic particles were then emitted into the environment, and the particles hold vital clues about the extent and types of meltdown processes. The team’s new results on boron-11/boron-10 isotopic ratios (~4.2) clearly indicate that most of the boron inside the CsMPs is derived from the FDNPP control rods and not from other sources (e.g., boron from the seawater that was used to cool the reactors). Dr Utsunomiya states that the presence of boron in the CsMPs “provides direct evidence of volatilization of the control rods, indicating that they were severely damaged during the meltdowns.”
Ample boron likely remains in the reactors, but more research is needed
In the study the team also combined their new data with past knowledge on CsMP emissions. From this, they have been able to estimate the total amount of boron released from the FDNPP reactors was likely very small: 0.024-62 g.
Prof. Gareth Law, a co-author from the University of Helsinki emphasized that this “is a tiny fraction of the reactor’s overall boron inventory, and this may mean that essentially all of the control rod boron remains inside the reactors.” The team hopes that this should prevent excessive fission reactions in the fuel debris. Utsunomiya stresses that “FDNPP decommissioning, and specifically fuel debris removal must be planned so that the extensive fission reactions do not occur. Our international team has successfully provided the first direct evidence of volatilization of B4C during the FDNPP meltdowns, but critically, our new data indicated that large quantities of boron, which adsorbs neutrons, likely remains within the fuel debris.”
Prof. Rod Ewing, a co-author from Stanford University acknowledged the importance of these new findings but highlighted that the team’s measurements now need to be “extended in follow-up studies, where the occurrence and distribution of boron species should be characterized across a wide range of debris fragments.”
Prof. emeritus Bernd Grambow, a study co-author from SUBATECH, Nantes, France,highlights that the work “paves the way for improving the safety assessment of debris retrieval during decommissioning at FDNPP,” with the team’s methods “providing a template for further studies.” Utsunomiya concludes that “it is nearly 11 years since the FDNPP disaster. In addition to tireless efforts from engineers at the FDNPP, scientific contributions are becoming more and more important as tools to address the major difficulties that will be faced during decommissioning.”
Journal Reference:
- Kazuki Fueda, Ryu Takami, Kenta Minomo, Kazuya Morooka, Kenji Horie, Mami Takehara, Shinya Yamasaki, Takumi Saito, Hiroyuki Shiotsu, Toshihiko Ohnuki, Gareth T.W. Law, Bernd Grambow, Rodney C. Ewing, Satoshi Utsunomiya. Volatilization of B4C control rods in Fukushima Daiichi nuclear reactors during meltdown: B–Li isotopic signatures in cesium-rich microparticles. Journal of Hazardous Materials, 2022; 428: 128214 DOI: 10.1016/j.jhazmat.2022.128214
University of Helsinki. “Can reactor fuel debris be safely removed from Fukushima Daiichi?.” ScienceDaily. ScienceDaily, 25 January 2022. www.sciencedaily.com/releases/2022/01/220125093041.htm.
Footage reveals highly radioactive area in crippled Fukushima Daiichi
21 sept. 2021
The Nuclear Regulation Authority reveals footage of a highly radioactive area in Fukushima Daiichi, which may affect decommissioning plans.
Japan eyes disposal abroad of radioactive plant equipment
Watch out! Japan’s hoping to export now its radioactive junk!
September 20, 2021
Japan plans to ease regulations to allow exports of large, disused equipment from nuclear power plants for overseas disposal as a way to reduce the mountains of radioactive waste accumulating at home.
The setup would mark a major shift from the government’s existing principle of disposing of all radioactive waste inside the country.
The industry ministry mentioned the revised disposal policy in the draft of the updated Basic Energy Plan, which awaits Cabinet approval in October at the earliest.
Even if the plan is approved, it will likely take some time for the government and nuclear plant operators to clear a slew of hurdles, such as estimating the costs of the project and ensuring the safety of shipments.
The Ministry of Economy, Trade and Industry, which oversees the nuclear industry, is considering outsourcing the disposal of three kinds of large low-level radioactive equipment overseas: steam generators, feed-water heaters and nuclear fuel storing and shipping casks.
These components range in size from 5 to 20 meters and weigh 100 to 300 tons.
Although they are not highly contaminated, compared with nuclear debris generated by spent fuel, they must be disposed of and managed properly, including being buried deep in the ground for years.
The ministry is considering their export as an “exceptional measure” to deal with the grave issue of the radioactive waste accumulating at nuclear facilities across Japan.
“Export regulations will be reviewed to allow for export (of low-level radioactive waste) when certain conditions are met, such as their safe recycling into useful resources,” the draft for the latest version of the Basic Energy Plan said.
The industry ministry is soliciting public opinions on the outsourcing plan until Oct. 4.
Nuclear plant operators have decided to decommission 24 reactors, including the six units at the crippled Fukushima No. 1 nuclear plant.
Work to dismantle those reactors is expected to go into full gear starting in 2025.
Excluding the reactors at the Fukushima plant, the decommissioned units will produce an estimated 165,000 tons of low-level radioactive waste.
But more than 90 percent of that waste has nowhere to go for dismantling and disposal.
Japan still lacks a dedicated disposal site for equipment used at nuclear plants, forcing plant operators to store the waste at their facilities.
The ministry says the storage of the out-of-service equipment is getting in the way of the decommissioning process.
Experts say some businesses in the United States and Sweden clean, melt and recycle metal from radioactive waste sent by foreign countries.
“Japan should first learn the know-how of disposal by outsourcing the work to foreign businesses with a reliable track record in the area and eventually become capable of doing it at home,” said Koji Okamoto, a professor of nuclear engineering at the University of Tokyo.
Under the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management, signatory countries that produce radioactive waste are obliged, in principle, to dispose of it within their territories.
But they can export the waste as exceptional cases if they obtain the consent of countries where business partners are based.
However, Japan’s Foreign Exchange and Foreign Trade Control Law bans such exports.
Utilities have pressed the government for a change in the disposal policy, and the industry ministry has been reviewing the existing setup alongside experts on nuclear technology.
Although the ministry intends to follow the principle of doing away with the waste within Japan, it plans to approve exports of the three types of nuclear plant equipment on condition that they will be recycled.
Ministry officials say the plan can be achieved through a revised ministry directive, without having to change the law.
The equipment intended for recycling overseas could include components kept at nuclear plants that still generate power.
But the ministry needs to work out many issues to turn the plan into reality.
Nuclear plant operators have the primary responsibility for disposing of low-level radioactive waste. And the actual costs these Japanese companies would have to pay to recyclers overseas is still unknown.
The bill could be far more expensive than initially estimated.
How to safely ship the radiation-contaminated equipment abroad is another unresolved issue.
The amount of nuclear waste in Japan has been growing since the 2011 Fukushima nuclear disaster. Utilities have gradually resumed operations at nuclear plants, but some have decided to decommission reactors, particularly aging ones, largely because of the costs needed to upgrade them under new safety standards.
For decades, Japan has been unable to secure a final disposal site for such waste inside the country, mainly because of opposition from residents of candidate sites.
Decade after Fukushima disaster, Greenpeace sees cleanup failure
Greenpeace has recommended that Japan suspend the current return policies, which it says “ignore science-based analysis, including potential lifetime exposure risks to the population” and abandon plans to lift evacuation orders in six municipalities
Mar 4, 2021
Ten years after the worst nuclear accident since Chernobyl, land Japan identified for cleanup from the triple reactor meltdown of the Fukushima No. 1 power plant remains contaminated, according to a report from Greenpeace.
On average, just 15% of land in the “Special Decontamination Area,” which is home to several municipalities, has been cleaned up, according to the environmental advocacy group’s analysis of government data. That’s despite the government’s claims that the area has largely been decontaminated, the group said.
In addition, Greenpeace said its own radiation surveys conducted over the last decade have consistently found readings above government target levels, including in areas that have been reopened to the public. The lifting of evacuation orders in places where radiation remains above safe levels potentially exposes people to an increased risk of cancer, the report said.
“The contamination remains and is widespread, and is still a very real threat to long term human health and the environment,” the report said.
Japan’s Ministry of Environment wasn’t immediately available for comment. Decontamination efforts have reduced radiation levels in residential areas by an average of 76%, according to the ministry’s website, which has compiled monitoring data through 2018. Fukushima Prefecture wasn’t immediately available for comment.
More than 160,000 people were evacuated from the area surrounding the Fukushima nuclear plant after a magnitude 9 earthquake, the biggest ever recorded to hit Japan, caused a massive tsunami that overwhelmed the plant. While the government has been steadily lifting evacuation orders on towns since 2014, roughly 36,000 people are still displaced.
Greenpeace recommended that Japan suspend the current return policy, which “ignore science-based analysis, including potential lifetime exposure risks to the population” and abandon plans to lift evacuation orders in six municipalities.
https://www.japantimes.co.jp/news/2021/03/04/national/fukushima-greenpeace-radiation-health-3-11/
Decades-long challenge to scrap Fukushima plant by 2051 in a bind
March 1, 2021
The decades-long challenge to scrap the Fukushima Daiichi nuclear plant, crippled by the massive earthquake and tsunami disaster that struck northeastern Japan in 2011, is becoming more complex as recent remote-controlled probes have highlighted just how damaged the reactors are.
Tokyo Electric Power Company Holdings Inc., operator of the six-reactor nuclear complex, aims to scrap the plant between 2041 and 2051. But critics have cast doubts on the schedule, citing not only the extremely high radiation levels, but problems associated with delayed probes and underdeveloped robots and other technology needed to extract an estimated nearly 900 tons of melted fuel debris.
Decommissioning of the plant, scene of the world’s worst nuclear accident since the 1986 Chernobyl disaster, is crucial for Japan if it wants to stick to using nuclear power safely and show the world that the nuclear crisis is under control.
“It is likely that the roadmap will not be completed as scheduled,” said Tetsuro Tsutsui, a member of the Citizens’ Commission on Nuclear Energy, a group comprising academics and nuclear experts.
He added the “melted debris is mixed with fractured parts of buildings and concrete material and is highly radioactive, making it hard for robots to clear the debris.”
The scrapping of the plant involves the daunting decision on how to dispose of the huge amount of radioactive waste left as a byproduct. This has been made worse as no municipality offered to become the final disposal site when the plant was operating.
Following a magnitude-9.0 earthquake and subsequent tsunami that hit the plant on March 11, 2011, Nos. 1 to 3 reactors at the Fukushima Daiichi plant suffered meltdowns, while hydrogen explosions damaged the buildings housing the Nos. 1, 3 and 4 reactors.
Photo taken on Nov. 12, 2011, shows the No. 3 reactor building at the Fukushima Daiichi nuclear power plant in Fukushima Prefecture, northeastern Japan, which was damaged by an explosion after the March 11 earthquake and tsunami.
Due to the instability of renewable energy, Japan projects atomic power will remain one of its major power sources, accounting for 20 to 22 percent of its total electricity generation in fiscal 2030. It may further push the emissions-free nuclear power as it aims to become carbon neutral in 2050.
Of the 33 reactors in Japan, excluding those set to be scrapped, just four are currently in operation, partly because they need to clear stricter safety regulations following the Fukushima accident.
Tsutsui, a former petrochemical complex engineer, points to how the risk of extracting debris has become “clearer” compared to when the roadmap was first compiled in December 2011. With that in mind, he urged the government to act responsibly and review the roadmap.
“Nearly 10 years have passed following the Fukushima accident but with respect to the long decommissioning process, we are still hovering around the start line. We have a long journey ahead,” said Fukushima Gov. Masao Uchibori in a recent briefing.
“The most difficult step is the safe and stable retrieval of the debris but we don’t know what state it is in,” he added.
Fukushima Daiichi nuclear complex on Feb. 21, 2018. From right, No. 1, No. 2, No. 3 and No. 4 reactors.
Despite the use of computer simulations and small-scale internal probes using remote cameras, data is scarce about the exact locations and other details of the melted fuel — crucial information to determine the retrieval methods and develop the appropriate technology and robots.
Robotic probes at the Nos. 2 and 3 units have captured images of large amounts of material that appear to be melted fuel, but attempts so far have been unsuccessful at the No. 1 unit.
TEPCO opted to start the fuel removal at the No. 2 unit as it has the best grasp of the internal conditions there but no time frame has been set for the two other units.
In a setback for retrieval efforts, the company said in late December removing melted fuel from the No. 2 unit would be delayed from its initial starting period in 2021 by at least a year as the coronavirus pandemic has stalled the development in Britain of a robotic arm to be used for the extraction.
That robotic arm, however, can only extract a few grams of melted fuel debris at a time. To completely remove the hundreds of tons of melted fuel from the reactor larger machinery is required, experts say.
In another development that may affect the decommissioning process, a Nuclear Regulation Authority study group said in January a high concentration of radioactive cesium is likely to have accumulated in the lids of the containment vessels for the No. 2 and No. 3 reactors.
The regulator’s findings in a new interim report draft on the Fukushima accident came as a shock because it was previously believed that most of the radioactive material remained at the bottom of the reactors in the form of melted nuclear fuel debris.
While industry minister Hiroshi Kajiyama has acknowledged the “delays” and “difficulties in making predictions,” he insisted the overall decommissioning process is making “steady progress.” The government and TEPCO say they will stick to the current roadmap.
TEPCO, whose biggest shareholder is the Japanese government, has not given an estimate of the costs for the debris removal, which would add to the 8 trillion yen ($75 billion) already forecast for the decommissioning process.
The utility and the government have also been grappling with the buildup of radioactive water, which is generated in the process of cooling the meltdown reactors.
Part of the water is stored inside massive tanks set up inside the premises, having gone through a system that removes various radioactive materials except tritium, which is difficult to separate from water.
Tanks containing treated water including radioactive tritium are stored on the premises of the Fukushima Daiichi nuclear complex on Feb. 21, 2018.
The government is considering dumping the water into the Pacific after diluting it to a radiation level below the legal limit, saying the tanks are filling up. It says space is needed to store debris once it is extracted from the damaged reactors.
But discharging the water remains a sensitive issue especially for the local fishing industry struggling to revive its business following the accident. Neighbors South Korea and China as well as U.N. human rights experts have expressed caution about the discharge.
Releasing it into the ocean could lead to a continued ban on exports from this area or an introduction of new export restrictions, observers say.
According to Yasuro Kawai, another member of the commission, the government’s decision to release treated water into the sea is in fact the government’s attempt to minimize the impact of the Fukushima crisis and say dismantling work is on track.
“But the roadmap is nothing but pie in the sky,” he said.
The commission says it is more logical to keep the debris inside the reactors than to retrieve it and suggests constructing a shield around the reactors and postpone taking out the melted fuel until 100 years or 200 years later when radioactive activity levels have decreased.
Fukushima College robot wins top prize for nuclear decommissioning
The Mehikari robot developed by a team at Fukushima College
Jan 25, 2021
Fukushima – A robot created by a team from a technology college in northeastern Japan recently won the top prize in a robotics competition that had the theme of decommissioning the Fukushima No. 1 nuclear power plant.
The Mehikari robot of Fukushima College earned praise for its speed as well as ability to employ different methods to retrieve mock debris similar in size to that at the plant, the site of a nuclear disaster triggered by a massive earthquake and tsunami on March 11, 2011.
The robot completed the set task in about 2 minutes, the fastest time, in the annual competition aimed at fostering future engineers that was attended by students from 13 colleges belonging to the National Institute of Technology.
Sunday’s competition was the fifth of its kind. Students in 14 teams from the colleges across the country such as in Osaka and Kumamoto prefectures were tasked this year with developing robots to remove fuel debris from the plant, organizers said.
“I’ll be happy if our robot is useful on the ground,” said Hiroha Toba, the 18-year-old leader of the winning team.
The robots were required to pass through a 4-meter-long pipe, land on a pedestal, collect balls representing fuel debris situated 3.2 meters below and return within 10 minutes.
The robots had to be remotely operable without a direct line of sight.
Also according to the contest rules, radio waves could not penetrate certain sections of the field, resembling the real-life situation in which the Fukushima No. 1 plant is covered by thick concrete walls. This meant the teams had to transmit directions by wire when the robots passed those areas.
Due to the coronavirus pandemic, the teams submitted videos of the robots’ performance to the organizers in advance. They were evaluated based on speed, accuracy and originality of retrieval method.
The competition was mainly organized by the Japan Atomic Energy Agency and had the support of the education ministry and other entities.
Agency: Fukushima plant workers should be heard
Oct. 11, 2020
A government agency overseeing the decommissioning of the crippled Fukushima Daiichi nuclear plant is urging the plant’s operator to take into account the views of workers in removing radioactive debris, set to start next year.
Each year, the Nuclear Damage Compensation and Decommissioning Facilitation Corporation compiles its technical policy for the plant’s decommissioning. This year’s plan was recently announced.
It refers to the removal of fuel debris from the plant’s No.2 reactor starting next year. It warns that the work will take place in conditions where there is little information about the interior environment and a high level of radiation.
The agency proposes that Tokyo Electric Power Company seriously take into account the views and concerns of on-site workers, such as the operators of machinery used to remove fuel debris.
It calls for the information obtained from workers to be reflected in the design of equipment used to scrap the reactor.
The agency’s proposals will be reflected in TEPCO’s mid- and long-term schedules for decommissioning the plant.
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