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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.

https://www3.nhk.or.jp/nhkworld/en/news/20201011_24/

October 18, 2020 Posted by | Fukushima 2020 | , | Leave a comment

Japan diver reflects on unsung workers exposed to radiation as Fukushima 10th anniv. Looms

Hisashi Okazaki is seen doing diving work at the Fukushima Daiichi Nuclear Power Plant’s No. 3 reactor in May 2006, in this image provided by Okazaki.

October 11, 2020

Have you ever heard of atomic divers? Hisashi Okazaki, 58, who has worked at nuclear power plants as a diver while being exposed to radiation, wants people to know that professional divers like himself work in dangerous conditions for nuclear reactors to run, as the 10-year anniversary of the Fukushima nuclear disaster approaches.

Among the places he has worked in his 33-year career as a professional diver is the Fukushima Daiichi Nuclear Power Plant, which would later go on to enter a meltdown following the Great East Japan Earthquake and resultant tsunami in March 2011.

Hisashi Okazaki is seen in Ehime Prefecture on Sept. 18, 2020.

After graduating high school, Okazaki, a resident of Seiyo in the western Japan prefecture of Ehime, entered the Japan Ground Self-Defense Force. Four years later he left, and got his professional diving license. Since then, he has worked primarily as a self-employed diver taking on jobs both at home and abroad, fulfilling tasks including laying oil pipelines and tetrapod sea defenses, as well as fixing sea walls damaged after the 1995 Great Hanshin Earthquake. He keeps illustrations of his dives as a record of what he’s done, and in all he has amassed more than 3,670 so far.

In 2006, a diver Okazaki knew invited him to work nuclear jobs. It was his first time working inside nuclear power facilities and being exposed to radiation, but he agreed to do it. Looking back, he said he did it because “I thought I wanted to experience anything I could. I had no fears.” His daily pay was 47,000 yen, almost twice the regular pay of around 25,000 yen for a day’s normal diving work.

Ahead of the job, 20 divers came together to train at a facility belonging to a heavy machinery maker situated in Kanagawa Prefecture south of Tokyo. They had on special heavy helmets weighing around 15 kilograms, and wore dry suits altered to stop water from entering them. They were hooked up to six cables, including for an air hose, photography, and radiation measurements. Both of their arms and legs as well as their chests were fitted with dosimeter equipment. After a week of training, the divers were dispersed to a number of nuclear plants across the country. Okazaki was dispatched to the Fukushima Daiichi Nuclear Power Plant’s No. 3 reactor.

There, he dived into the plant’s suppression chamber, which cools the reactor containment vessel in the event that the release of steam causes its pressure to rise. The chamber is a doughnut-shaped facility in the lower part of the vessel, with water about 3 meters deep in it. The maintenance work Okazaki undertook had to be done while it was filled and he did the work with another diver to exchange equipment in the facility.

An illustration of a diver replacing equipment underwater is seen in this image provided by Hisashi Okazaki.

The area where they worked had high doses of radiation, and in a single day’s diving they could work for about two hours. When they approached an area with a particularly high dosage, they would be instructed via a voice cable not to proceed further. The divers stayed in Fukushima Prefecture for about a month. Legal occupational exposure limits to radiation for a worker are set at 50 millisieverts per year, but in just the 12 days Okazaki worked at the plant, he was exposed to a total of 7.34 millisieverts. At the end of the job, the contaminated equipment they’d used was all put into a drum and disposed of.

“I couldn’t feel satisfied doing a job that leaves no trace of it behind,” Okazaki said. On his way back from Fukushima to Tokyo, Okazaki asked himself while in a car the purpose of his work that exposed him to radiation, and the younger diver who worked with him on the job said, “We did this for that view (of the city) at night, didn’t we?” Okazaki felt a little bit relieved by what they’d said, and after that he went on to do underwater cleaning work at the Onagawa Nuclear Power Station in northeast Japan’s Miyagi Prefecture.

Then, in March 2011, the Great East Japan Earthquake struck. Okazaki watched images of the hydrogen explosion at the Fukushima Daiichi Nuclear Power Station’s No. 3 reactor from a TV on a work barge in the sea off the Muroto Misaki cape in Kochi Prefecture, western Japan. “I’d never imagined the power would be lost and it would explode,” he said.

The use of divers for the decommissioning of the crippled nuclear reactor, such as in removal work and other tasks, is being considered. Even now, around 4,000 people are working at the Fukushima Daiichi plant each day. The decommissioning work, which is expected to take decades from now to finish, is employing robots to complete some tasks, but still the role of radiation-exposed human workers is vital. Okazaki said, “Even at the reactors that use the most technologically advanced equipment, there are sections which only human hands can deal with, and divers are part of the group of workers who take up such jobs.”

(Japanese original by Shunsuke Sekiya, City News Department)

https://mainichi.jp/english/articles/20201009/p2a/00m/0na/020000c

October 12, 2020 Posted by | Fukushima 2020 | , , | Leave a comment

Ikata nuclear reactor to be shut down – 40 year decommissioning process

Regulator approves Ikata 2 decommissioning plan

Japan’s Nuclear Regulation Authority (NRA) today approved Shikoku Electric Power Company’s decommissioning plan for unit 2 of its Ikata nuclear power plant in Ehime prefecture. Decommissioning of the unit is expected to be completed by 2059.

The three-unit Ikata plant

07 October 2020

Ikata 2 is a 538 MWe pressurised water reactor that began operating in March 1988. It was taken offline in January 2012 for periodic inspections. Shikoku announced in March 2018 that it did not plan to restart the reactor. It said the cost and scale of modifications required to upgrade the 40-year-old unit to meet the country’s revised safety standards made it uneconomical to restart it.

The utility submitted an outline of its plans for decommissioning the unit to the NRA on 10 October, 2018. Shikoku also submitted requests to Ehime prefecture and the municipality of Ikata, as specified under nuclear safety agreements concluded with those authorities.

Following a review, which included a total of seven public meetings, the NRA has today approved the decommissioning plan for Ikata 2.

According to the plan, decommissioning of the unit will take about 40 years and will be carried out in four stages. The first stage, lasting about 10 years, will involve preparing the reactor for dismantling (including the removal of all fuel and surveying radioactive contamination), while the second, lasting 15 years, will be to dismantle peripheral equipment from the reactor and other major equipment. The third stage, taking about eight years, will involve the demolition of the reactor itself, while the fourth stage, taking about seven years, will see the demolition of all remaining buildings and the release of land for other uses.

During the first stage, all fuel is to be removed from the unit. This includes 316 used fuel assemblies that will be sent for reprocessing and 102 fresh fuel assemblies that will be returned to the fuel fabricator.

“In the future, we will obtain the consent of Ikata Town and Ehime Prefecture, based on the safety agreement,” Shikoku said.

Shikoku decided in March 2016 to decommission unit 1 of the Ikata plant, also a 538 MWe PWR, which began commercial operation in September 1977. That unit had been taken offline in September 2011 for periodic inspections. Upgrades costing more than JPY170 billion (USD1.5 billion) would have been needed at the unit in order for it to operate beyond 40 years. The NRA approved Shikoku’s decommissioning plan for Ikata 1 in June 2017. That plan also sees the unit being decommissioned in four stages over a 40-year period.

The utility said, “As with unit 1, we will steadily proceed with the decommissioning of unit 2 with the highest priority given to ensuring safety.”

https://www.world-nuclear-news.org/Articles/Regulator-approves-Ikata-2-decommissioning-plan

October 12, 2020 Posted by | Japan | , , | Leave a comment

9 1/2 years after meltdowns, no end in sight for Fukushima nuke plant decommissioning

The No. 1 reactor building is seen at the Fukushima Daiichi Nuclear Power Station in Okuma, Fukushima Prefecture, on Sept. 1, 2020.

September 22, 2020

It has been some 9 1/2 years since the triple-meltdown disaster at the Fukushima Daiichi Nuclear Power Station in northeast Japan, and in early September I visited the plant to get a close-up look at the reactor buildings and find out how much progress is being made in dismantling them.

The trip began aboard a microbus, which stopped on an inland promontory running north to south at an elevation of 33.5 meters above sea level. Getting off the bus, I looked east, over the Pacific Ocean. And then I saw them, just 100 meters away or so: the buildings containing the plant’s No. 1 to 4 reactors.

When a tsunami triggered by the March 11, 2011 Great East Japan Earthquake slammed into the coastal facility, reactors 1 to 3 were online, while No. 4 was shut down for a regular inspection. There were core meltdowns in all three of the active reactors, with the fuel mixing with material from the surrounding structure as it melted and turned into “fuel debris.” Later, the No. 4 reactor building, connected to the No. 3 building by plumbing, was blown apart by a hydrogen explosion.

To complicate matters further, the reactor buildings had fuel storage pools each containing between 392 and 1,534 nuclear fuel rods. However, the plant workers managed to keep the rods cool, averting a major secondary disaster.

On my visit, the No. 3 reactor building is encased in what looks like a Baumkuchen layer cake stood upright. Inside, operations are underway to remove the fuel rods from the 12-meter-deep storage pool.

“There’s a newly installed crane in there to take the fuel out,” said our guide Masayuki Ueda, who is a manager at the Fukushima Daiichi decommissioning unit of the plant’s operator, Tokyo Electric Power Company Holdings (TEPCO).

The hydrogen explosion choked the pool and surrounding area with debris, including fragments of the roof and bits of nearby machinery. Even after the clearing of this debris, equipment and other problems delayed the fuel removal operation by more than four years. The process finally got underway in April 2019. The special crane lifts the some 300-kilogram rods out of the pool one at a time, and they are then taken to a pool in a separate building. Of the 566 rods, 366 had been removed as of Sept. 11, 2020. Due to the high radiation in the building itself, the crane is operated remotely from a control facility about 500 meters away.

The hardest part of the task is yet to come; the handles on 16 of the rods were warped by falling debris, and can’t be extracted by the crane as they are. TEPCO is apparently working on a “grabbing tool” for the crane to lift out the damaged rods, among other methods, in hopes to finish the removal project by March 2021.

We get back on the microbus and head down the hill to a spot where we can look up at the No. 4 reactor building. Here, too, we can see the machinery for the so-called underground ice wall surrounding the No. 1-4 reactors.

Groundwater from the mountains flows relentlessly beneath the power station. The walls in the basement levels of the reactor buildings were cracked in the March 2011 quake, letting in the groundwater and rainwater that has come into contact with the nuclear fuel debris, contaminating it. The “ice wall,” which TEPCO began making in May 2013, is TEPCO’s attempt to control the problem.

The wall is made up of some 1,500 pipes sunk 30 meters into the ground, creating a subterranean perimeter about 1.5 kilometers long around the reactor buildings. Liquid cooled to minus 30 degrees Celsius is then run through the pipes, freezing the soil around them. The Japanese treasury spent about 34.5 billion yen (about $330.7 million) to make the wall, and the electricity and other maintenance to keep it going costs hundreds of millions of yen per year. These latter outlays are passed on to consumers in their power bills.

Previously, the stricken plant produced up to 600 metric tons of contaminated water per day. However, thanks to pumping up groundwater on the landward side of the plant and other measures, that was down to 160 tons per day in April through July this year. Under the plant decommissioning plan, TEPCO and the Japanese government intend to reduce that to 150 tons per day by the end of 2020, and 100 tons by 2025. TEPCO has said that, with work on new roofs over the reactor buildings proceeding, it believes it can meet the 150 ton target this year.

Meanwhile, with radiation levels around the reactor buildings gradually declining, the Nuclear Regulation Authority (NRA) believes it is the moment to consider going into the basement levels to patch the cracks in the walls. NRA Chairman Toyoshi Fuketa has said that “it’s about time to start discussing when to halt” the ice wall operation.

There are experts who doubt the efficacy of the ice wall. In 2018, TEPCO estimated the wall alone was preventing 95 tons of contaminated water from being generated per day. However, Hideyuki Ban, co-director of the nonprofit organization Citizens’ Nuclear Information Center, told the Mainichi Shimbun, “There needs to be an inquiry into whether the ice wall was ever really necessary.”

Parts of the Fukushima Daiichi decommissioning plan have been delayed repeatedly since its release in December 2011. At that time, the plan stated it would take 30-40 years to complete the project. However, after seeing the power station up close, I find it hard to imagine this.

(Japanese original by Suzuko Araki, Science and Environment News Department)

https://mainichi.jp/english/articles/20200921/p2a/00m/0na/018000c

September 24, 2020 Posted by | Fukushima 2020 | , | Leave a comment

Robot to use brush to retrieve melted fuel at Fukushima plant

jkllmmThe robotic arm to be used for collecting melted fuel at the No. 2 reactor of the Fukushima No. 1 nuclear power plant (Provided by the International Research Institute for Nuclear Decommissioning)

hkjlkmA vacuum vessel to collect powdered nuclear debris (Provided by the International Research Institute for Nuclear Decommissioning)

July 27, 2020

FUKUSHIMA–A robotic arm under development in Britain will use a brush and vacuum vessel on its end to collect melted fuel in a step toward retrieving debris at the crippled Fukushima No. 1 nuclear power plant.

Details of the device, which will start collecting debris inside the No. 2 reactor on a trial basis next year, were announced on July 2.

The government and plant operator Tokyo Electric Power Co. plan to retrieve melted fuel at the No. 2 reactor ahead of two other reactors because radiation levels are relatively low.

The No. 2 reactor, along with the No. 1 and No. 3 reactors, suffered meltdowns following the Great East Japan Earthquake and tsunami in 2011.

The situation inside the No. 2 reactor is relatively known through past inspections. It has been confirmed that apparent debris in the lower part of its containment vessel can be collected with a robot.

Measuring 22 meters long and weighing 4.6 tons, the robotic arm will be made of high-strength stainless steel so it will not bend when stretched out.

It will be inserted into a closed box connected to a hole made on the side of the containment vessel and remotely operated to prevent radioactive substances from being released.

The arm will attach powdered nuclear debris to its brush and also suck the debris with its vacuum vessel.

Under the plan, debris totaling approximately 1 gram or so will be collected in each of the several rounds of the trial procedure.

An experiment will start in Britain as early as August with the use of a model of the containment vessel.

The robotic arm will be transported to Japan around February for the training of operators at the Japan Atomic Energy Agency’s facility in Naraha, Fukushima Prefecture.

The retrieved fuel will be measured for weight and radiation levels, put in a metal transfer vessel and moved to an analysis center in Ibaraki Prefecture.

In the full-scale retrieval stage, different equipment will be used.

Melted fuel to be removed is estimated to record a radiation reading of 6 millisieverts per hour even at distances of 20 centimeters from it.

That means the annual dose limit for ordinary individuals of 1 millisievert will be reached in 10 minutes.

Training is expected to reduce the time required for workers to put debris into the transfer vessel near the fuel.

Other measures to lessen workers’ doses will be taken, such as introducing panels to block radiation.

http://www.asahi.com/ajw/articles/13529394

August 3, 2020 Posted by | Fukushima 2020 | , , | Leave a comment

Experts propose two methods to scrap Daiichi plant

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July 26, 2020

Japanese atomic energy experts have proposed two ways to decommission the crippled Fukushima Daiichi nuclear power plant.

The Atomic Energy Society of Japan floated the two methods in a report.

One proposal is to dismantle and remove all parts of the reactor buildings and leave the site vacant. The other is to dismantle and remove parts of the reactor buildings that are above ground and leave behind the underground structures.

The experts say each method has been studied in the United States and European countries.

They say amounts of radioactive waste to be generated during decommissioning work will vary significantly, depending on when the dismantling of reactor buildings begins — namely, starting to dismantle contaminated buildings soon or waiting a certain period for their radiation levels to drop.

A decommissioning timeline released by the Japanese government and the plant’s operator, Tokyo Electric Power Company, shows the scrapping process will be completed by 2051. But the plan is unclear on how the reactor buildings will be decommissioned.

Miyano Hiroshi, a member of the Atomic Energy Society of Japan, says it will be difficult to draw a conclusion from various arguments on how to decommission the plant. But he adds discussions are important and that he hopes the society’s report will contribute to the debate.

https://www3.nhk.or.jp/nhkworld/en/news/20200726_14/?fbclid=IwAR135prg8cmB7Yw5kdFWbeCitGEIWkPqIxi6Hgryx-PV-2HwN9ksZKld7CU

August 3, 2020 Posted by | Fukushima 2020 | , | Leave a comment

Fukushima decommissioning work to be downsized

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April 17, 2020

Tokyo Electric Power Company Holdings, Inc. said Thursday that it is preparing to reduce the number of workers involved in decommissioning the Fukushima No. 1 nuclear power plant, in response to the state of emergency being expanded to all 47 prefectures.

About 3,000 employees and staff from partner companies are currently working at the plant to decommission the reactors and other tasks. The reduction in personnel is a measure to reduce the risk of the coronavirus spreading, however, the decommissioning process may be delayed if there is a prolonged reduction in staff.

TEPCO will maintain operations necessary for the stable management of the plant, including the cooling of melted fuel and nuclear fuel pools and the purification of contaminated water.

https://www.lmtonline.com/news/article/Fukushima-decommissioning-work-to-be-downsized-15207355.php

April 24, 2020 Posted by | Fukushima 2020 | , , | Leave a comment

Japan’s 3/11 Recovery Stalled by Fukushima Decommissioning Delays

thediplomat-2020-03-13-3

March 13, 2020

Delays in dismantling the disaster-stricken nuclear power complex cast doubt on whether recovery goals will move forward according to schedule.

Nine years after a quake-triggered tsunami sparked a triple meltdown at Fukushima Daiichi nuclear power plant, decontamination and decommissioning continues in northeastern Japan. The ultimate goal of removing all debris is expected to take anywhere between 30 to 40 years, but progress has been slower than originally planned. So far just one-fourth of decommission work has been completed, drawing attention to work that has not yet begun.

The Fukushima decommissioning and decontamination draft has been amended five times. While changes published in December offered a specific time frame for the first time, the latest timetable for debris removal has been pushed back five years, citing the need for additional safety precautions. Previously, the process of removing spent fuel was scheduled from 2021 to 2024. But work on reactor two looks more likely to start in 2025 and last until 2027, followed by reactor one work commencing sometime between March 2028 and March 2029.

The powerful tsunami, which reached over 40 meters in some areas, took the lives of 22,167 people. At the same time, the loss of power to the entire Fukushima Daiichi plant caused reactors one, two, and three to overheat, sparking hydrogen explosions and the release of radioactive contaminants. This forced 160,000 survivors to evacuate. Despite evacuation orders being lifted in some of the “difficult to return” areas, many still opt to stay away from their homes nine years later.

The next decommissioning stage sets out the removal of 4,471 spent fuel rods inside the cooling pools of reactors one to six. But the biggest obstacle is finding a way to locate and remove the molten nuclear fuel. With frequent delays, evacuees face a constant sense of uncertainty, tangled in a waiting game to see whether decommissioning work can be completed in 30 years.

Reactor two is seen as the safest and easiest option to start full-scale debris removal since it suffered the least structural damage with only “some fuel” melting through the pressure vessel and accumulating at the bottom of the containment vessel.  But with no established method for debris retrieval, attempts to survey the location and distribution of molten nuclear fuel among the rubble requires a lengthy trial and error process. In mid-February 2019 an attempt to probe and collect samples from reactor two failed to find and lift the main nuclear fuel debris, instead lifting portions of pebble-like sediment with the lowest radiation readings from the surface. At this stage there is no way for TEPCO, the company that owns the Fukushima Daiichi plant, to determine where fuel debris lies among the rest of the metal debris. It’s estimated that reactor two alone contains 237 metric tons of debris while reactors one and three contain a combined 880 tons. The complexity of debris removal requires developing specialized technology that does not yet exist.

Also plaguing decommissioning efforts is the battle over how to safely dispose of 1 million tons of contaminated water that were used to cool nuclear fuel. Currently, huge tanks on the premises store the polluted runoff, which could fill 400 Olympic swimming pools, but space is expected to run out by mid-2022.

On average 170 tons of contaminated water is produced to cool fuel in nuclear reactors. Without constant cooling, nuclear fuel risks melting from its own heat in a process called decay heat. With two years needed to prepare a disposal method, time is running out for a final decision.

Government proposals to slowly release contaminated water into the ocean has sparked fierce backlash from locals and the agriculture and fishing industries, who argue traces of radioactive materials such as tritium still found in “treated” water could further harm a region still struggling to restore its international reputation.

Last month, International Atomic Energy Agency (IAEA) Chief Rafael Mariano Grossi visited the Fukushima nuclear power plant where he commended the government’s “dual approach” of decommissioning the plant while revitalizing the local community. Grossi said the IAEA could help provide reassurance to the public that Japan’s plan to release treated water into the ocean meets international standards.

To make matters worse, decommissioning operations have been temporarily suspended due to the spread of coronavirus. Tepco was forced to cancel on-site inspections of reactor one scheduled during March, which would have brought together some 1,800 experts and members of parliament, as well as local residents and student groups.

https://thediplomat.com/2020/03/japans-3-11-recovery-stalled-by-fukushima-decommissioning-delays/

March 20, 2020 Posted by | Fukushima 2020 | , , | Leave a comment

Tepco estimates 44 years to decommission Fukushima No. 2 nuclear plant

They say that the first stage, comprising radiological surveys, will take ten years. The second stage, which will involve clearing the equipment from around the nuclear reactors, will last 12 years. Removal of the reactors (stage 3) and demolition of the reactor buildings (stage 4), will each last 11 years.

But these estimates are useless. The U.S. has been cleaning up Hanford, WA, site of the reactors that made the plutonium in the Alamagordo bomb, and then the Nagasaki bomb, for decades, at an every mounting cost and an ever-receding completion date. Turns out that generating large amounts of high-level nuclear waste turns out to be a bit more challenging to deal with than the techno-optimists ever dreamed. If there’s anyone around with the consciousness to care several hundred years from now, the creation of nuclear waste is going to be a very nasty reminder of how stupid we were.


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The Fukushima No. 2 nuclear power plant
January 23, 2020
Tokyo Electric Power Company Holdings Inc. has estimated that it will take 44 years to decommission its Fukushima No. 2 nuclear plant.
Tepco presented the outline of decommissioning plans to the municipal assembly of Tomioka, one of the two host towns of the nuclear plant, on Wednesday.
The Fukushima No. 2 plant is located south of the No. 1 plant, which suffered a triple meltdown accident in the wake of the March 2011 massive earthquake and tsunami.
According to the outline, the decommissioning process for the No. 2 plant will have four stages, taking 10 years for the first stage, 12 years for the second stage and 11 years each for the third and fourth stages.
Tepco will survey radioactive contamination at the nuclear plant in the first stage, clear equipment around nuclear reactors in the second, remove the reactors in the third and demolish the reactor buildings in the fourth.
Meanwhile, the plant operator will transfer a total of 9,532 spent nuclear fuel units at the plant to a fuel reprocessing company by the end of the decommissioning process, and 544 unused fuel units to a processing firm by the start of the third stage.
Tepco will submit its finalized decommissioning plans for the Fukushima No. 2 plant to the Nuclear Regulation Authority after gaining approval from the municipal governments of Tomioka and the other host town, Naraha, as well as the Fukushima Prefectural Government.

January 31, 2020 Posted by | Fukushima 2020 | , | 1 Comment

METI eyes 2031 end to Fukushima No. 1 cleanup

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The Fukushima No. 1 nuclear power plant is seen in this photo taken on March 11.
by Mari Yamaguchi
Dec 2, 2019
The industry ministry on Monday unveiled a revised plan to remove molten nuclear fuel debris from the meltdown-hit Fukushima No. 1 power plant in 2021 — a process said to be the biggest hurdle to decommissioning the six-reactor facility.
Work to remove the debris should start with the No. 2 reactor, according to the mid- to long-term road map released by the government.
Designating a specific time frame for the first time, the plan also calls for completing the removal of 4,741 fuel rods left inside the cooling pools for reactor Nos. 1 to 6 by 2031.
“As more people return and rebuilding progresses in the areas around the No. 1 plant, we will take measures based on the basic principle of balancing rebuilding and decommissioning,” said Minister of Economy, Trade and Industry Hiroshi Kajiyama, who heads the state team tasked with decommissioning the heavily damaged plant.
The plan, revised for the fifth time, maintains the general outlook for finishing the cleanup within 30 to 40 years of the triple meltdown, which was triggered by the mega-quake and tsunami on March 11, 2011.
But, given issues that have halted work and caused delays so far, it remains uncertain whether the plan will proceed as scheduled.
Here is a look at some of the challenges facing Fukushima No. 1:
Melted fuel debris
By far the toughest challenge is removing the 800 tons of nuclear fuel that melted in the three reactors before dropping from their cores and hardening at the bottom of the primary containment vessels.
Over the past two years, Tepco has made progress gathering details mainly from two of the reactors. In February, a small telescopic robot sent inside the No. 2 reactor showed that small pieces of debris can come off and be lifted out. Thus debris removal is scheduled to begin there by the end of 2021.
Earlier, assessments of the No. 3 reactor were hampered by high radiation and water levels in the PCVs. A robot survey at the No. 1 reactor also failed from extremely high radiation.
Experts say a 30- to 40-year completion decommissioning target is too optimistic. Some doubt that removing all of the fuel is even doable and suggest an approach like Chernobyl — contain the reactors and wait until radioactivity naturally fades.
Fuel rods
Together, the three reactors have more than 1,500 units of mostly spent nuclear fuel rods inside that must be kept cool in pools of water. They’re among the highest risks at the plant because the pools are uncovered, and loss of water from structural damage or sloshing in the event of another major quake could cause them to melt and release massive radiation.
The manager of the plant, Tokyo Electric Power Company Holdings Inc., started removing rods from the No. 3 reactor pool in April and aims to get all 566 out by March 2021. Removal of rods from units 1 and 2 is to begin in 2023.
By 2031, Tepco plans to remove thousands of rods at the two units that survived the tsunami and store them in dry casks on the compound. Over 6,300 fuel rods were in the six reactor cooling pools at the time, and only the pool at No. 4 has been emptied.
Tainted water
The government and Tepco have been unable to get rid of the more than 1 million tons of radioactive water that has been treated and stored on site, fearing public repercussions. The utility has managed to cut the volume by pumping up and diverting groundwater upstream, as well as by installing a costly underground “ice wall” around the reactor buildings to keep water from entering.
Tepco says it only has space for up to 1.37 million tons until summer 2022, raising speculation it might release the tainted water after the 2020 Olympics. Tepco and experts say that the tanks are hampering decommissioning work and that the space they occupy must be freed up to build storage for the debris and other radioactive materials to be removed. There is also the risk that the tanks might fail and release their contents in the event of another quake, tsunami or flood.
Experts say a controlled release of the water into the ocean is the only realistic option, one that will take decades. For years, a government panel has been discussing methods amid opposition from fishermen and residents who fear it will damage their products and their health.
Radioactive waste
Japan has yet to develop a plan to dispose of the highly radioactive waste that will come out of the reactors. Under the road map, the government and Tepco will compile a plan sometime after the first decade of removal work ends in 2031.
Managing the waste will require new technologies to compact it and reduce its toxicity. Tepco and the government say they plan to build a temporary storage site for the waste. But finding a site and getting public consent to store it there will be nearly impossible, raising doubts the cleanup can be finished within 40 years.
Manpower concerns
Securing a workforce for the decades-long project is yet another challenge, especially in a country with a rapidly aging and declining population. Tepco announced plans to hire foreign workers for the decommissioning process under Japan’s new visa program to attract unskilled foreign labor, but put it on hold after receiving government instructions on careful planning to address concerns about language problems and safety. Universities are also struggling to attract students in nuclear science, a formerly elite major that has become unpopular since the Fukushima crisis.

 

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December 8, 2019 Posted by | fukushima 2019 | , | 1 Comment

New minister prioritizes Fukushima decommission

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September 14, 2019
Jiji Press FUKUSHIMA (Jiji Press) — The economy, trade and industry ministry will steadily promote decommissioning work at the stricken Fukushima No. 1 nuclear power plant, new minister Isshu Sugawara said Friday.
“Decommissioning work and disposal of tainted water at the plant are the ministry’s highest priorities,” Sugawara said in a meeting with Fukushima Gov. Masao Uchibori.
The nuclear plant, owned by Tokyo Electric Power Company Holdings Inc., is the site of a triple reactor meltdown in March 2011.
Sugawara, who took office on Wednesday as part of Prime Minister Shinzo Abe’s Cabinet reshuffle, said the ministry will also step up support to businesses in areas hit by the nuclear disaster.
Uchibori sought to move nuclear fuel stored at TEPCO’s Fukushima No. 2 nuclear plant, which will also be decommissioned, out of his prefecture.
Speaking to reporters after the meeting, Sugawara said the ministry will work responsively on tackling treated water at the Fukushima No. 1 plant that contains tritium, a radioactive substance.

September 26, 2019 Posted by | Japan | , | Leave a comment

Japan urges nuke plants to get ready for decommission era

hjhkjk.jpgTokyo Electric Power Co.’s Fukushima No. 2 nuclear power plant

 

September 2, 2019

Japan’s nuclear policy-setting body adopted a report Monday saying the country is entering an era of massive nuclear plant decommissioning, urging plant operators to plan ahead to lower safety risks and costs requiring decades and billions of dollars.

Twenty-four commercial reactors–or 40 percent of Japan’s total–are designated for or are being decommissioned. Among them are four reactors at the Fukushima No. 1 nuclear power plant that were severely damaged by the massive 2011 earthquake and tsunami that struck northeastern Japan.

The annual nuclear white paper, adopted by the Japan Atomic Energy Commission, urges utilities to learn from U.S. and European examples, especially those of Germany, France and Britain. Japan hasn’t yet completed the decommissioning of any reactors and doesn’t have concrete plans for the final disposal of radioactive waste.

“Taking into consideration further increase of nuclear facilities that will be decommissioned, new technology and systems need to be developed in order to carry out the tasks efficiently and smoothly,” the report said. “It’s a whole new stage that we have to proceed to and tackle.”

Japanese utilities have opted to scrap aged reactors instead of investing in safety requirements under post-Fukushima standards. The decommissioning of a typical reactor costs nearly 60 billion yen ($560 million) and takes several decades.

Before the Fukushima disaster, Japan had 60 commercial reactors that provided about 25 percent of the country’s energy needs.

Despite the government’s renewed ambitions for nuclear power, reactor restarts are proceeding slowly as nuclear regulators spend more time on inspections. Meanwhile, anti-nuclear sentiment persists among the public and makes it more difficult for plant operators to obtain local consent in making revisions to their facilities. Any plan related to nuclear waste storage tends to get strong resistance.

Since the Fukushima accident, only nine reactors in Japan have restarted, accounting for about 3 percent of the country’s energy supply, compared to the government’s ambitious 20-22 percent target.

In July, Tokyo Electric Power Holdings Co., or TEPCO, announced plans to decommission all four reactors at its second Fukushima plant, Fukushima No. 2, which narrowly avoided meltdowns in 2011. The move followed eight years of demands by the local government and residents for the reactors’ closure.

TEPCO said the decommissioning of Fukushima No. 2 alone would cost 410 billion yen and would take four decades, but experts have raised concerns about whether those estimates are realistic for a company already struggling with the ongoing cleanup of the wrecked Fukushima plant, estimated to cost about 8 trillion yen.

Japan Atomic Power Co., which has been decommissioning its Tokai nuclear plant since 2001, announced in March that it was pushing back the planned completion of the project by five years, to 2030, because the company still has been unable to remove and store highly radioactive materials from the core. The decommissioning of the government’s Tokai fuel reprocessing facility is expected to take 70 years and cost 770 billion yen.

The white paper stated that Japan is pursuing its divisive spent-fuel reprocessing ambitions and a plan to develop a fast-breeder reactor despite international concerns over the country’s plutonium stockpile of 47 tons, though the commission calls for more efforts in reducing the stockpile and increasing transparency.

France’s recently reported move to abandon ASTRID, its next-generation fast reactor that would theoretically produce more plutonium while burning it as fuel, could be a setback for Japan, which was hoping to jointly develop the technology.

http://www.asahi.com/ajw/articles/AJ201909020026.html

September 8, 2019 Posted by | Japan | , | Leave a comment

TEPCO submits decommissioning plan for Onagawa 1

Another Japanese boiling water reactor calls its quits and moves to decommission. This the fifth Japanese boiling water reactor in a week pulled from even having hope of restart along with Fukushima Daini 1 through 4. Who says “operating experience” isn’t shrinking for boiling water reactors in USA and around the world?
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02 August 2019
Tohoku Electric Power Company has applied to Japan’s Nuclear Regulation Authority (NRA) for approval of its decommissioning plan for unit 1 of the Onagawa nuclear power plant in Miyagi Prefecture. The company announced in October 2018 its decision to scrap the unit as it said required safety upgrades would be too expensive and time-consuming.
Unit 1 of the 524 MWe boiling water reactor (BWR) that began operations in 1984 is of a different design to the other two larger (825 MWe) BWR units there, which began operating in 1995 and 2002, respectively. Tohoku also operates a single 1100 MWe BWR at its Higashidori plant in Aomori Prefecture, which started operation in late 2005. Tohoku plans to restart units 2 and 3 at the Onagawa plant, as well as its Higashidori plant.
Last October, Tohoku said a problem unique to Onagawa 1 is the restricted space within its containment vessel in which to install additional safety equipment, such as fire extinguishing equipment, power supply equipment and alternative water injection pumps. It decided to decommission the unit after taking into account its generating capacity and the number of years it would be able to operate if it were restarted. Onagawa 1 became the tenth operable Japanese reactor to be declared for decommissioning since the March 2011 Fukushima Daiichi accident.
Its decommissioning plan for the unit, which it submitted  to the NRA on 29 July, outlines the facilities and equipment to be dismantled and a timetable for completing the work. Decommissioning will take about 34 years and will be carried out in four stages. The first stage, lasting about eight years, will involve preparing the reactor for dismantling (including the removal of all fuel and surveying radioactive contamination), while the second, lasting seven years, will be to dismantle peripheral equipment from the reactor and other major equipment. The third stage, taking about nine years, will involve the demolition of the reactor itself, while the fourth stage, taking about ten years, will see the demolition of all remaining buildings and the release of land for other uses.
During the first stage, all fuel is to be removed from the operation of Onagawa 1. This includes 821 used fuel assemblies stored in unit 1’s storage pool, which will be transferred to unit 3’s storage pool. These assemblies will later be transported for reprocessing, together with 95 used fuel assemblies from unit 1 currently stored at unit 2 and 66 stored at unit 3. There are also 41 unused fuel assemblies stored at unit 1.
A total 60 tonnes of high-level radioactive waste is expected to be generated through the decommissioning of Onagawa 1, together with 740 tonnes of low-level waste and 5340 tonnes of very low-level waste. A further 12,400 tonnes of non-radioactive waste will also be generated through the clearance of the site.
Tohoku said it expects the decommissioning of the unit to cost a total of JPY41.9 billion (USD392 million), with dismantling activities costing JPY30.0 billion and waste disposal accounting for the remainder.
In March 2015, the Ministry of Economy, Trade and Industry’s Agency for Natural Resources and Energy revised the accounting provisions in the Electricity Business Act, whereby electric power companies can now calculate decommissioning costs in instalments of up to 10 years, instead of one-time as previously. This enhanced cost recovery provision was to encourage the decommissioning of older and smaller units.
The Onagawa plant is on Japan’s northeastern coast and was the closest plant to the epicentre of the earthquake and tsunami of 11 March 2011. Although the earthquake knocked out four of the five external power lines, the remaining line provided sufficient power for the plant’s three reactors to be brought to cold shutdown. Onagawa 1 briefly suffered a fire in the non-nuclear turbine building. A mission from the International Atomic Energy Agency in August 2012 concluded the plant had been largely unaffected by the tsunami as it sits on an elevated embankment more than 14 metres above sea level.

August 3, 2019 Posted by | Japan | , | Leave a comment

Decision to Scrap Fukushima Daini 4 Reactors

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TEPCO officially decides to abolish Fukushima Daini nuclear plant
This photo taken from a Kyodo News helicopter on June 14, 2018, shows the Fukushima Daini nuclear power plant in Fukushima Prefecture, northeastern Japan.
July 31, 2019
TOKYO (Kyodo) — Tokyo Electric Power Company Holdings Inc. officially decided Wednesday at a board meeting to abolish the Fukushima Daini nuclear complex near the Daiichi plant crippled by the March 2011 disaster.
It means that all 10 nuclear reactors in the northeastern prefecture, including the six at the Fukushima Daiichi complex, will be scrapped, though this will take decades. TEPCO President Tomoaki Kobayakawa met Fukushima Gov. Masao Uchibori and reported the decision.
The decommissioning work of the four nuclear reactors at the Daini plant will likely cost some 280 billion yen ($2.6 billion) and require more than 40 years. The power company plans to build an on-site facility to store spent nuclear fuel from the plant, though it has yet to pick a final disposal site for the fuel.
The Daini complex started the four reactors’ commercial operation from 1982 to 1987. The nuclear power plant was also hit by the tsunami in the 2011 disaster, temporarily losing key cooling functions, but managed to avoid meltdowns that occurred at the Daiichi plant.
The prefecture has called for scrapping the Daini plant, saying its existence has been hampering reconstruction efforts.
 
Fukushima gov. accepts TEPCO decision to scrap Daini nuclear plant
This photo taken on June 14, 2018, shows the Fukushima Daini nuclear power plant in the northeastern Japan prefecture of Fukushima
July 31, 2019
FUKUSHIMA, Japan (Kyodo) — Fukushima Gov. Masao Uchibori said Tuesday his prefecture will accept Tokyo Electric Power Company Holdings Inc.’s recent decision to scrap the Fukushima Daini nuclear complex near the Daiichi plant crippled by the March 2011 disaster.
In a meeting with Tomoaki Kobayakawa, the president of the utility known as TEPCO, the governor also accepted its plan to build an on-site storage facility to store spent nuclear fuel.
The decision means all 10 nuclear reactors in the northeastern prefecture, including the six at the Fukushima Daiichi complex 12 kilometers from the Daini plant, will be scrapped, though the decommissioning work will take decades.
The March 2011 earthquake and tsunami did not cause serious structural damage to the Daini plant, while three of the reactors at the Daiichi complex experienced meltdowns.
TEPCO’s decision to scrap the Daini complex, expected to cost around 280 billion yen ($2.6 billion), will be formally approved at the company’s board meeting on Wednesday.
“I’m grateful that I received a certain degree of understanding. We will proceed (with the decommissioning) with a renewed sense of responsibility,” Kobayakawa said in the meeting with the governor.
Uchibori and Kobayakawa discussed TEPCO’s plan last week, with the governor saying that while he welcomed the scrapping of the reactors he needed to consult the towns hosting the complex about the storage facility.
TEPCO has not picked a final disposal site for the spent fuel from the Daini complex, raising concern among local residents that the radioactive nuclear waste may remain stored on-site for a long time.
“The premise is that the nuclear fuel will be transported out of the prefecture. Temporary storage for the time being is unavoidable,” Uchibori said.
He later told reporters TEPCO had assured him that the storage facility would not be permanent.
The Daini plant currently has around 10,000 assemblies of spent fuel cooling in pools.
The scrapping of the Daini plant also means that the central government’s annual subsidies of around 1 billion yen ($9.2 million) each for the towns of Naraha and Tomioka that host the facility will eventually be terminated.
Revenue linked to the nuclear plant, from property taxes and in other forms, accounted for 25 percent of Naraha’s total revenue and 40 percent of Tomioka’s.
Uchibori said he will ask the government to take into account “the financial situation of the two towns in view of the special circumstances relating to the decommissioning.”

August 3, 2019 Posted by | fukushima 2019 | , | Leave a comment

TEPCO bears responsibility for decommissioning over generations

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Tokyo Electric Power Co.’s Fukushima No. 2 nuclear power plant
July 29, 2019
Tokyo Electric Power Co. has announced that it will decommission all four reactors at its Fukushima No. 2 nuclear power plant.
The decision indicates the landscape of nuclear energy in Japan is entering an age of mass decommissioning.
TEPCO plans to work concurrently to scrap a total of 10 nuclear reactors, including all six at the Fukushima No. 1 nuclear power plant, the site of the 2011 disaster. The task will be almost unparalleled and unprecedented in the world in terms of its scale.
TEPCO should fulfill its momentous duties in undertaking the task to help rebuild disaster-stricken communities of Fukushima Prefecture.
It took TEPCO an entire year to make the latest decision after the utility said last year it would consider the decommissioning option. That is enough evidence there are high barriers to be surmounted.
One difficulty consists in ensuring the availability of workers.
A staff of 3,600 is currently working to scrap the Fukushima No. 1 nuclear plant, where four reactors went crippled. Work to grasp the full picture of the reactor interiors, where nuclear fuel melted down, remains in a trial-and-error stage and is facing extremely rough going.
The latest decision means the Fukushima No. 2 plant, a logistic support base for those efforts, will itself be an additional site of decommissioning work.
TEPCO officials said they have largely figured out how the work will be done. We are left to wonder, however, how they plan to get all the necessary, highly skilled workers.
The task should be undertaken cautiously and steadily so there will be no accidents.
While it is believed it takes about 30 years to decommission a typical nuclear reactor, TEPCO officials said it will likely take more than 40 years to scrap all the reactors at the Fukushima No. 2 plant because the work cannot be done on all four reactors there in one continuous period.
That is about the same span of time that someone spends working for a company from entrance as a new hire through retirement age. The efforts will straddle generations.
TEPCO will be required to keep its staff highly motivated and to overcome any difficulties responsibly during all that time.
While the scrapping work will only start after specific plans for it have been approved by the government’s Nuclear Regulation Authority, solutions have yet to be decided for many anticipated problems.
The four reactors of the Fukushima No. 2 plant contain about 10,000 spent nuclear fuel assemblies. TEPCO plans to have them stored temporarily on the grounds of the nuclear plant before having them taken out of Fukushima Prefecture.
But where exactly they will be taken “will be studied in the years to come,” said Tomoaki Kobayakawa, president of TEPCO Holdings Inc.
Some rules remain to be determined for the disposal of radioactive waste, of which more than 50,000 tons are expected to be produced.
Decommissioning of nuclear reactors is a challenge that faces all major electric utilities.
Decisions have been made to scrap 21 nuclear reactors in the wake of the Fukushima disaster, and more are expected over time.
The question of what to do with spent fuel and radioactive waste should not be put on the back burner. The government should work to solve it.
Rising costs due to tightened safety measures have given a push to utilities’ decisions to scrap their reactors. Only nine reactors have so far been brought back online following the Fukushima disaster.
Plans to build new nuclear plants and reactors are making little progress. As a matter of reality, nuclear energy is losing the status of a mainstay power source.
That notwithstanding, utilities still stick to their old stance of continued reliance on nuclear power, saying they want to utilize what they have.
TEPCO is no exception. The owner of seven reactors at the Kashiwazaki-Kariwa nuclear plant in Niigata Prefecture is hoping to reactivate the No. 6 and No. 7 reactors there for starters.
Major utilities, especially TEPCO, are required to face up to the tough reality and look at what lies beyond the age of mass decommissioning. They bear the social responsibility to assign ample human and financial resources for renewable energy sources, which will be a major pillar of power supply for the next generation, among other areas.

July 31, 2019 Posted by | fukushima 2019 | , , , , | Leave a comment