Aging Fukui nuclear unit to restart in Aug., 2 months early
June 10, 2022
An aging nuclear reactor in central Japan’s Fukui Prefecture will resume operating in August, about two months earlier than scheduled, with the unit expected to help ease tight electricity supply conditions during the busy summer season, its operator said Friday.
After being offline for about 10 years, Kansai Electric Power Co.’s Mihama No. 3 reactor initially restarted in June last year, becoming the first nuclear unit to operate beyond the government-mandated 40-year service period introduced under new rules set after the 2011 Fukushima disaster.
But the No. 3 unit was then suspended just four months after its restart after failing to meet the Oct. 25 deadline set by regulators to implement antiterrorism measures.
Kansai Electric said it will now start operation of a designated safety facility in late July and thus bring forward the schedule for the reactor’s restart from Aug. 12.
With the reactor back online, it is hoped the country’s power reserve rate, except for Hokkaido and Okinawa, in August will improve to 4.7 percent from 4.4 percent. The reactor was initially scheduled to operate from Oct. 20.
While the No. 3 unit was given the green light to operate, the Nos. 1 and 2 units of the plant in Mihama on the Sea of Japan coast were terminated in April 2015 in line with the 40-year limit.
Disaster-prone Japan has recently been struggling to provide stable power supply, with most of its nuclear power plants remaining offline under stricter safety regulations imposed since the Fukushima nuclear accident and an increasing number of aging thermal power plants being shut down.
“We will operate our nuclear plants in a safe manner while considering current challenges in the power supply and demand,” Kansai Electric said in a statement.
Even so, power supply still looks tight this summer as the government projects the reserve rate to drop to 3.1 percent in July, just 0.1 point above the required level for stable power supply.
Economy, Trade and Industry Minister Koichi Hagiuda on Friday urged the public again to save energy such as by setting air conditioning to 28 C, turning off unnecessary lights and avoiding stacking too much food in refrigerators.
TEPCO puts cost to remove melted nuclear fuel at over 1 trillion yen
A video image shows what appears to be melted nuclear fuel within the No. 3 reactor at the Fukushima No. 1 nuclear power plant.
March 31, 2020
Tokyo Electric Power Co. estimates that 1.37 trillion yen ($12.6 billion) will be needed over 12 years to remove melted nuclear fuel from reactors at the crippled Fukushima No. 1 nuclear power plant.
TEPCO’s announcement on March 30 covers only two of the three reactors that suffered meltdowns triggered by the 2011 Great East Japan Earthquake and tsunami.
No estimate was attempted for the cost to prepare for the removal of melted nuclear fuel from the No. 1 reactor. The situation at that reactor is the most difficult among the three reactors, and TEPCO officials are still struggling to come up with a plan for removing the debris from within.
The estimate covers the period between fiscal 2020 and fiscal 2031. Of that amount, 350 billion yen will be applied as a special loss to the company’s balance statement for the fiscal year ending March 31, 2020.
The utility had already released its plan for decommissioning the three reactors, which foresaw a start to removing melted nuclear fuel from the No. 2 reactor before the end of 2021, while removal would begin for the No. 3 reactor by 2031.
In announcing its expected profits for the current fiscal year, TEPCO also outlined its estimated expenses for melted fuel removal over the next 12 years.
A total of 330 billion would be needed as preparatory measures, such as further examining the interior of the No. 2 reactor and decontaminating radiation from the area around the three reactors.
Another 20 billion yen is expected to be spent for trial removal of melted nuclear fuel from the No. 2 reactor, while 1.02 trillion yen would be required to construct the facilities needed to remove the melted fuel from the No. 2 and No. 3 reactors.
The construction cost would be written off as a special loss from TEPCO’s balance statement in the fiscal year when the work takes place.
TEPCO forecasts a net profit of 79 billion yen for the current fiscal year, a decrease of 66 percent from fiscal 2019. Sales are expected to decrease by 2.2 percent to 6.199 trillion yen.
http://www.asahi.com/ajw/articles/13259804
Yamaguchi court rejects residents’ call to halt last Ikata nuclear reactor in Ehime Prefecture
Supporters for the plaintiffs hold banners that read “Unjust ruling” and “Have you forgotten Fukushima?” after the Iwakuni branch of the Yamaguchi District Court rejected a plea to halt a nuclear reactor in Ehime Prefecture, on Friday in Iwakuni, Yamaguchi Prefecture.
March 15, 2019
YAMAGUCHI – A district court on Friday rejected a plea by residents to halt a reactor at the Ikata nuclear power plant in Ehime Prefecture.
The decision by the Iwakuni branch of the Yamaguchi District Court is in line with rulings made by other regional courts and allows the No. 3 reactor to continue operating. The plant is managed by Shikoku Electric Power Co.
Unit No. 3, the sole remaining reactor at the plant, passed the state safety screening process that was revamped in the wake of the 2011 Fukushima nuclear crisis. But concerns remain about its safety, which led residents to turn to the courts to seek an injunction.
Of the more than 30 reactors in Japan, excluding those set to be decommissioned, only a few are in operation.
Read more :
Shikoku Electric restarts Ikata nuclear reactor following failed court challenges
The No. 3 unit at the Ikata nuclear power plant had been idle since October 2017 before restarting Saturday
MATSUYAMA, EHIME PREF. – Shikoku Electric Power Co. on Saturday restarted a reactor at its Ikata nuclear power plant after a suspension of nearly one year due to a high court order.
The restart of the No. 3 unit at the plant in the town of Ikata, Ehime Prefecture, announced by the power company overnight Friday, came after a high court accepted an appeal by the utility in a late September ruling that there are no safety risks associated with potential volcanic activity in the region.
The utility said the unit reached criticality, a controlled self-sustaining nuclear fission chain reaction, on Saturday evening as planned.
It said it will start producing and transmitting electricity on Tuesday, before possibly putting the reactor into commercial operation on Nov. 28.
The decision by the Hiroshima High Court was an about-face from its provisional injunction issued in December last year that demanded the power company halt the No. 3 unit until Sept. 30, following a request from a local opposition group. The group argued that Shikoku Electric underestimated the risk of pyroclastic flows reaching the plant if there is a major eruption at Mount Aso, about 130 km away.
The temporary suspension order was the first in which a high court banned operations at a nuclear plant since the 2011 meltdowns at the Fukushima No. 1 complex.
But the high court said on Sept. 25 that the group’s claim of a possible destructive volcanic eruption during the plant’s operating period has no satisfactory grounds and that there is a small chance of volcanic ash and rocks reaching the facility. A Hiroshima court on Friday also rejected a call from residents to have the restart blocked.
The reactor had been idle for maintenance since last October. Before that, it had gone back online in August 2016 after clearing stricter safety regulations implemented in the wake of Fukushima.
“We’d like Shikoku Electric to constantly pursue improvements in safety and reliability, and information disclosure with high transparency,” Ikata Mayor Kiyohiko Takakado said.
New reactor being built in western Japan applies for safety checks
This file photo taken on May 21, 2018, shows Shimane Nuclear Power Plant’s No. 3 reactor in Matsue, Shimane Prefecture, western Japan. (Kyodo)
August 10, 2018
TOKYO (Kyodo) — Chugoku Electric Power Co. on Friday applied to the government for safety screening of a nuclear reactor it is constructing, opening up the possibility of it becoming Japan’s first newly built reactor to go into operation since the 2011 Fukushima crisis.
Work on the No. 3 unit at the Shimane plant in Matsue, Shimane Prefecture, is almost complete and safety checks by nuclear regulators may proceed faster than for another reactor in northeastern Japan that is also under construction.
The No. 3 reactor will have a maximum output of 1,373 megawatts, making it one of the largest in the country. It is a boiling water reactor, the same type as those at Tokyo Electric Power Company Holdings Inc.’s disaster-hit Fukushima Daiichi nuclear power plant.
Chugoku Electric was initially aiming to activate the reactor in December 2011 after starting construction in 2006. But the plan was postponed following the Fukushima nuclear crisis, triggered by a massive quake and tsunami disaster that hit northeastern Japan.
The crisis led to the introduction of more stringent safety standards for nuclear power plants. Around 10 reactors have resumed operation in Japan after clearing the safety hurdles, but there has been no case in which new reactors have been activated after the disaster.
“With existing nuclear reactors currently restarting, we thought it is possible to file for checks of the No. 3 unit (even though it is a new reactor),” Tatsuo Kitano, managing executive officer of the utility based in Hiroshima Prefecture, told reporters.
The latest development came a day after Shimane Gov. Zembee Mizoguchi officially gave the green light for Chugoku Electric’s application for government screening.
But prospects remain unclear on when the reactor will be put into service as the utility will not just have to clear the safety tests but also again seek local consent for operation.
Chugoku Electric is spending around 500 billion yen ($4.5 billion) on safety measures for the No. 3 reactor, aiming to finish the work by September 2019.
The other new reactor that is seeking to start operation is being built at Electricity Power Development Co.’s Oma nuclear power plant in Aomori Prefecture.
The company known as J-Power applied for government safety checks in 2014, but the process has been drawn out. The Oma reactor is expected to become the world’s first commercial reactor to run fully on plutonium-uranium mixed oxide fuel.
TEPCO Opens Up Space in Common Pool at Fukushima Daiichi to Receive Spent Fuel from Unit 3
“X-6 penetration” at Unit 5
4 June, 2018
On May 31, the Tokyo Electric Power Co. (TEPCO) released a progress report on the decommissioning at the Fukushima Daiichi Nuclear Power Plants.
Four days earlier, on May 27, the power company began transferring some of the spent fuel currently stored in a common pool to a temporary facility at the site, for storage in dry casks, to create enough space in the pool to store spent fuel taken from the Unit 3 spent fuel pool when that is eventually removed.
At the temporary storage facility, TEPCO will pack the spent fuel in dry casks providing shielding and heat removal (with natural air circulation outside the casks) and store it under stable conditions.
By August, 483 spent fuel assemblies from the common pool will have been transferred to the facility using seven transport and storage casks, in anticipation of the arrival of 566 fuel assemblies (including unused 52 assemblies) from Unit 3.
On May 11, a problem was found at Unit 3—where a fuel handling machine has been in trial operation since March—inside a control panel for a crane used for moving fuel transportation containers to the ground. TEPCO nevertheless aims to begin removing fuel from the spent fuel pool around mid-FY18, as initially planned.
TEPCO will determine a method for removing fuel debris from the first unit by FY19 (April 2019 to March 2020), and the status of that effort was also included in the status report on May 31. The approach is to proceed after heightened understanding is made of internal conditions, the nature of the debris, and the effects when removed.
As that has not yet been fully completed, though, the effort will proceed gradually and incrementally, as follows: first investigating the interiors of the primary containment vessels (PCVs) through sampling, then carrying out small-scale removal of debris, followed by large-scale removal.
As for small-scale fuel removal, one promising method seems to be using a “X-6 penetration” rail to access the interiors of the PCVs (found in all the units) from the side, in order to exchange the control rod drive mechanism (CRDM). That method is already being used for inserting investigation devices into PCVs.
Coastal nuclear reactor resumes operations, joins 2 units nearby
The No. 1 to No. 4 reactors (from top to bottom) at the Oi Nuclear Power Plant are seen from a Mainichi Shimbun helicopter, in Oi, Fukui Prefecture, on March 14, 2018.
March 14, 2018
FUKUI, Japan (Kyodo) — Kansai Electric Power Co. restarted Wednesday a reactor at its Oi plant on the Sea of Japan coast, located close to two other units already online, amid lingering safety concerns following the Fukushima disaster.
It is the first time that multiple nuclear reactors within the same vicinity have been in operation since the crisis at the Fukushima Daiichi plant, triggered by the March 2011 earthquake and tsunami.
The No. 3 reactor at the Oi plant is a mere 14 kilometers from the No. 3 and 4 units at the Takahama plant, all in the central Japan prefecture of Fukui.
Local residents are worried about the lack of an effective evacuation plan in the event accidents hit both the Takahama and Oi complexes at the same time.
The No. 3 Oi unit is the sixth reactor to resume operations in Japan after clearing stricter safety regulations implemented in the wake of the Fukushima disaster.
The government of Prime Minister Shinzo Abe, seeing nuclear power as an “important base-load power source,” is promoting the restart of nuclear reactors considered safe by regulators.
Under the current national energy policy, the government plans to generate between 20 and 22 percent of total electricity using nuclear power in fiscal 2030.
Kansai Electric aims to start commercial operations of the No. 3 Oi reactor in early April. The No. 4 reactor at the Oi plant is also expected to restart in May, having cleared the Nuclear Regulation Authority’s safety review along with the No. 3 unit in May 2017.
Roof completed for removal of spent fuel rods at Fukushima plant
February 21, 2018
Work was completed Feb. 21 on a half-cylinder roof designed to trap radioactive substances emitted when spent fuel rods are removed from the No. 3 reactor building at the Fukushima No. 1 nuclear plant.
Tokyo Electric Power Co., the plant’s operator, plans to remove the spent fuel from the building’s storage pool as early as this autumn.
Construction work on the roof–23 meters wide and 57 meters long–started in July 2017.
The final piece, weighing about 55 tons, was lifted by a crane and put into place on Feb. 21. The roof is located directly above the storage pool.
A hydrogen explosion severely damaged the original roof of the No. 3 reactor building days after the March 2011 Great East Japan Earthquake and tsunami triggered the meltdowns at the plant.
The 566 fuel assemblies in the storage pool pose a serious risk in the event of another disaster striking the plant.
Completion of the roof should advance TEPCO’s plans to remove the fuel rods as soon as possible.
The final part of a roof is put in place on the top of the No. 3 reactor building at the Fukushima No. 1 nuclear power plant on Feb. 21.
A photo taken from an Asahi Shimbun helicopter on Feb. 21 shows the completion of work for a roof at the No. 3 reactor building of the Fukushima No. 1 nuclear power plant on Feb. 21.
The half-cylinder roof is designed to prevent radioactive substances from escaping during fuel-rod removal work in the No. 3 reactor building at the Fukushima No. 1 nuclear plant.
Fukushima plant reactor #3 gets new roof cover
Workers at the crippled Fukushima Daiichi nuclear power plant have finished installing a new roof covering for the No.3 reactor building.
The work started last August to set up a dome-shaped cover. It is part of preparations for removing nuclear fuel from the reactor’s storage pool. A total of 566 spent and unused fuel units remain in the storage pool of the No. 3 reactor.
On Wednesday, workers installed the last part of the cover, which is 17 meters high and 22 meters wide, and weighs 55 tons.
The cover will prevent radioactive materials from spreading, and shield the building from winds.
Reactors at the Fukushima plant suffered meltdowns after a quake-triggered tsunami hit the plant on March 11th, 2011. The fuel units left in storage pools need to be removed as part of decommission work at the plant.
The plant’s operator, Tokyo Electric Power Company, will clear the pool of rubble and provide workers with training on remotely handling devices for the fuel removal.
Then, it plans to start removing nuclear fuel units from the No.3 reactor’s storage pool in autumn this year, ahead of those of other damaged reactors.
Inside a meltdown-hit Fukushima reactor building
February 17, 2018
Seven years on, Tepco aims to pull fuel out of Unit 3’s rubble-strewn pool
A crane and dome-shaped roof have been erected on the top floor of Fukushima Daiichi’s No. 3 building, in preparation for removing rods and rubble from the spent fuel pool
FUKUSHIMA, Japan — As the Fukushima Daiichi nuclear disaster unfolded in March 2011, a hydrogen explosion ripped through the No. 3 reactor unit. Nearly seven years on, steel framing and other debris still litter the spent fuel pool, along with 566 fuel rods.
The painstaking process of removing the rods is expected to begin sometime in the fiscal year that starts in April. The fuel extraction will be a first for reactor Nos. 1-3 at the Tokyo Electric Power Co. Holdings facility, which was crippled by the earthquake and tsunami that hit northeastern Japan.
On Feb. 8, reporters from The Nikkei were allowed into the No. 3 building to get a sense of the work that awaits.
A 20-minute bus ride from the town of Tomioka took us to Fukushima Daiichi. After donning masks and protective clothing, we walked toward Unit 3. An elevator slowly lifted us to the top floor of the building, about 36 meters up. There, a crane for moving the spent rods stood ready, wrapped in plastic sheeting. We peered down into the pool but could not see the fuel, which lies under 4 to 5 meters of water.
Large slabs of rubble that fell into the pool have been removed, but smaller pieces remain.
Other decontamination work is proceeding gradually. Radiation on the top floor was measured as high as 2,000 millisieverts per hour in the disaster’s immediate aftermath, but now it is less than 1 millisievert.
Still, caution is a must. Near the pool, our dosimeters displayed relatively high readings of up to 0.7 of a millisievert per hour. “The reading has climbed, so let’s leave for now,” a Tepco supervisor said. As we moved on, we frequently checked to ensure our exposure would not exceed 0.1 of a millisievert a day.
Spent fuel has been removed from reactor No. 4, which was not operating when the tsunami hit the plant. But the job will be a challenge at the meltdown-stricken Unit 3. The rods and rubble will be extracted with heavy equipment operated remotely, from a separate administrative building.
While it normally takes about two weeks to remove spent fuel, Tepco intends to proceed carefully over the course of two years.
Drone to probe Fukushima N-plant interior
February 10, 2018
Tokyo Electric Power Company Holdings Inc. plans to use a small unmanned aerial vehicle to closely inspect conditions inside the No. 3 reactor building of the Fukushima No. 1 nuclear power plant as early as this month.
TEPCO will use the drone to examine the location of scattered debris and the level of radiation inside the reactor building, among other things.
It will be the first drone-based research conducted inside the plant’s Nos. 1, 2 and 3 reactor buildings, in which nuclear meltdowns occurred.
The drone, called Riser, was developed by a British company. It measures 83 centimeters by 93 centimeters and weighs about four kilograms.
Riser is equipped with cameras and a dosimeter that can measure up to 2.5 sieverts of radiation per hour.
Even in indoor spaces inaccessible to GPS signals, the drone is capable of determining its position and avoiding obstacles using lasers.
The same model was used for decommissioning work at the Sellafield nuclear facility in Britain.
TEPCO’s plan is for the drone to enter the No. 3 reactor building through a bay for large cargo on the first floor, then fly upward through a series of openings from the first to the fifth floor.
The drone will check areas including the building’s third floor, which has not been sufficiently monitored because radiation levels are too high.
According to TEPCO, key equipment such as that used to cool spent nuclear fuel pools are located on the third floor.
Confirming the location of possible obstacles and the level of radiation is necessary before decommissioning work can progress.
Riser also has a mapping function that enables it to produce three-dimensional graphic images of its surroundings using lasers.
Combining these images with measurements of radiation levels allows for the production of maps outlining contamination levels inside the reactor buildings. TEPCO will consider making this kind of distribution map in the future.
A hydrogen explosion inside the No. 3 reactor building on March 14, 2011, destroyed the building’s upper structures.
Work is currently under way to construct a dome-shaped roof over the building to facilitate the removal of fuel that remains in the spent fuel storage pools.
Installation of a dome-shaped rooftop cover near completion at Unit 3 reactor
Japan Fukushima Cleanup
In this Thursday, Jan. 25, 2018 photo, an installation of a dome-shaped rooftop cover housing key equipment is near completion at Unit 3 reactor of the Fukushima Dai-ichi nuclear power plant ahead of a fuel removal from its storage pool in Okuma, Fukushima Prefecture, northeast Japan, during an exclusive visit by The Associated Press. The hardest-hit reactor at the Fukushima plant in the March 2011 disaster is moving ahead of the other two melted reactors seven years later in what will be a decades-long cleanup. (AP Photo/Mari Yamaguchi)
Worst-hit reactor at Fukushima may be easiest to clean up
By MARI YAMAGUCHI
In this Thursday, Jan. 25, 2018, photo, an installation of a dome-shaped rooftop cover housing key equipment is near completion at Unit 3 reactor of the Fukushima Dai-ich nuclear power plant ahead of a fuel removal from… (AP Photo/Mari Yamaguchi)
OKUMA, Japan (AP) — High atop Fukushima’s most damaged nuclear reactor, the final pieces of a jelly-roll shaped cover are being put in place to seal in highly radioactive dust.
Blown apart by a hydrogen explosion in 2011 after an earthquake and tsunami hit Japan’s Fukushima Dai-ichi plant, reactor Unit 3 is undergoing painstaking construction ahead of a milestone that is the first step toward dismantling the plant.
The operating floor — from where new fuel rods used to be lowered into the core — has been rebuilt and if all goes as planned, huge cranes will begin removing 566 sets of still-radioactive fuel rods from a storage pool just below it later this year.
It has taken seven years just to get this far, but now the real work of cleaning up the Tokyo Electric Power Co. plant can begin.
“If you compare it with mountain climbing, we’ve only been preparing to climb. Now, we finally get to actually start climbing,” said Daisuke Hirose, an official at the plant’s decommissioning and decontamination unit.
Cleaning up the plant’s three reactors that had at least partial meltdowns after the earthquake and tsunami is a monumental task expected to take three to four decades. Taking out the stored fuel rods is only a preliminary step and just removing the ones in Unit 3 is expected to take a year.
Still ahead is the uncharted challenge of removing an estimated 800 tons of melted fuel and debris inside the cracked containment chambers — six times that of the 1979 Three Mile Island accident.
The area in and outside of Unit 3 is part construction site and part disaster zone still requiring protection from radiation. A makeshift elevator, then a wind-swept outdoor staircase, takes visitors to the operating floor, more than 30 meters (100 feet) above ground.
Daylight streams in through the unfinished section of the new cover, a tunnel-like structure sealed at both ends to contain radiation. An overhead crane that moves on rails stands at the side of the storage pool, the maker’s name, “Toshiba,” emblazoned in large red letters.
The explosion left major chunks of debris that have been removed from the storage pool, a painstaking operation done using remote-controlled machinery and with utmost care to avoid damaging the fuel rods. Smaller rubble lines the pool’s edge. The water’s surface is obscured by a blue netting to prevent more debris from accidentally tumbling in.
The severe damage to Unit 3 has, in the end, made it easier to clean up than the other two reactors.
Under the latest government roadmap approved last September, removal of the fuel rods from units 1 and 2 was delayed by three years until 2023, a second postponement from the original 2015, because further decontamination and additional safety measures are needed.
Unit 1 fell behind because of a delay in removing debris and repairing key components on the operating floor. The Unit 2 building remained intact, keeping high radiation and humidity inside, which makes it more difficult for workers to approach and decontaminate.
Radioactivity on the Unit 3 operating floor has fallen to a level that allows workers in hazmat suits and filter-masks to stay up to two hours at a time, though most work still needs to be done remotely.
The segments of the new cover were pre-assembled and are being installed one by one by remote-controlled cranes. With two pieces left, the plant operator says the cover will be completed in February.
Removing the fuel rods in Unit 3 will be done with a fuel-handling crane. It will move the rods out of their storage racks and pack them in a protective canister underwater. A second Toshiba crane, a 10-meter (33-foot) -high yellow structure across the operating floor, will lift the canister out of the pool and load it onto a vehicle for transport to another storage pool at the plant.
Crane operators and others assigned to the project, which requires caution and skill, have been rehearsing the procedures.
The 1,573 sets of fuel rods stored in spent fuel pools at the three reactors are considered among the highest risks in the event of another major earthquake. Loss of water from sloshing, structural damage or a power outage could cause meltdowns and massive radiation leaks because the pools are uncovered.
Hirose said that starting fuel removal at Unit 3 would be “a major turning point.”
Still, after the intact fuel rods are gone comes by far the most difficult part of decommissioning the plant: removing the melted fuel and debris from inside the reactors. Obtaining exact locations and other details of the melted fuel are crucial to determining the retrieval methods and developing the right kind of technology and robots. With most melted fuel believed to have fallen to the bottom, experts are proposing that it be accessed from the side of the containment vessel, not from the top as originally had been planned, based on the cleanup after an accident at the Three Mile Island nuclear plant in the United States.
Computer simulations and limited internal probes have shown that the melted fuel presumably poured out of the core, falling to the bottom of the primary containment vessels. Robotic probes at the Unit 3 and 2 reactors have captured images of large amounts of melted fuel, but attempts so far at Unit 1 have been unsuccessful.
Despite scarce data from inside the reactors, the roadmap says the methods for melted fuel removal are to be finalized in 2019, with actual retrieval at one of the three reactors in 2021. Hirose says it is premature to say whether Unit 3 will be the first.
Fukushima dome roof takes shape, but radiation remains high
Construction continues on a domed roof on top of the No. 3 reactor building at the Fukushima No. 1 nuclear power plant.
High radiation levels are still limiting recovery work at the Fukushima No. 1 nuclear plant, a stark reality that reporters saw firsthand when they observed efforts to remove risk factors there.
Media representatives were invited into the plant in early December to see construction work, with the building of a domed roof over the No. 3 reactor building as the main focus.
However, they were only allowed to stay on top of the roof for 20 minutes due to high radiation levels.
The roof is being put together directly above the storage pool for spent fuel. The dome is designed to prevent the spewing of radioactive materials when the fuel is actually removed from the pool.
The original roof of the No. 3 reactor building was severely damaged by a hydrogen explosion in the days following the March 11, 2011, Great East Japan Earthquake and tsunami, which led to the crippling of the Fukushima No. 1 plant.
Spent fuel still remains in the storage pools located on the top floors of the No. 1 to No. 3 reactor buildings.
Plans call for removing the spent fuel first from the No. 3 reactor building.
Although the dome will help prevent the spread of radioactive materials, building parts and other debris as well as some equipment have still not been completely removed from the storage pool, which holds 566 fuel rods.
The collapsed roof and walls were removed to allow for the construction of the domed roof, which began in the summer. The domed roof is about 17 meters high, and a crane was also installed under it in November.
Plans call for the removal of the spent fuel from the No. 3 building to begin in the middle of the next fiscal year.
Internal radiation exposure levels were measured before media representatives headed to the No. 3 reactor building. They were also required to don protective clothing as well as a partial face mask covering the mouth and nose from about 100 meters from the building.
Radiation levels close to the building were 0.1 millisieverts per hour.
An elevator installed into the scaffolding next to the reactor building took the media representatives to the roof, which had been covered with metal plates.
The so-called operating floor looked like any other newly constructed building roof, a sharp contrast to the twisted metal parts that covered the building shortly after the nuclear accident.
Tokyo Electric Power Co., the plant’s operator, captured video footage from within the reactors for the first time in July. Debris that appears to be melted nuclear fuel was found in various parts of the containment vessel.
To the south of the No. 3 reactor building stands the No. 4 reactor building, from where all the spent nuclear fuel has been removed.
To the north is the No. 2 reactor building, which avoided a hydrogen explosion. Beyond the building, cranes and other large equipment are working in preparation for the removal of debris from the No. 1 reactor building.
TEPCO officials cautioned media representatives about standing too long right next to the storage pool, which could be seen located about six meters below the roof. Debris was found within the pool while insulating material floated on the pool surface.
The radiation level near the pool was 0.68 millisieverts per hour. While that was a major improvement from the 800 millisieverts per hour recorded in the immediate aftermath of the nuclear accident close to seven years ago, it was still too high to allow for a stay of longer than 20 minutes.
Image shows extent of damage to reactor at Fukushima plant
Severely damaged parts of a device once used to move control rods are stuck in a hole inside the pressure vessel of the No. 3 reactor at the Fukushima No. 1 nuclear plant. (Provided by International Research Institute for Nuclear Decommissioning)
An image taken by an underwater robot shows corroded tubes stuck in a hole created by melted fuel in the pressure vessel of the No. 3 reactor at the Fukushima No. 1 nuclear plant.
The image offers clues on the extent of the damage caused when fuel rods in the reactor melted through the bottom of the pressure vessel after the disaster at the nuclear plant unfolded in March 2011.
Tokyo Electric Power Co., operator of the plant, sent the specially designed robot into the reactor in July. The company earlier released images taken by the robot that showed ‘what is believed’ to be melted nuclear fuel debris.
In the image released on Nov. 30, TEPCO identified the severely corroded and damaged tubes as parts of a device used to move control rods. Normally, that device is located inside the pressure vessel.
TEPCO on Nov. 30 also said it would conduct another study inside of the containment vessel of the No. 2 reactor at the plant in January. The containment vessel surrounds the pressure vessel.
A telescopic stick more than 10 meters long and equipped with a camera will be used for the survey.
1.This Month
 |
|
|
See here the final program of the 12th International #Uranium Film Festival #Rio de Janeiro, May 18 – 28, 2023, Modern Art Museum (MAM Rio) #Cinematheque. uraniumfilmfestival.org/en/rio-2023-pr…
-
Archives
- May 2023 (313)
- April 2023 (348)
- March 2023 (308)
- February 2023 (379)
- January 2023 (388)
- December 2022 (277)
- November 2022 (335)
- October 2022 (363)
- September 2022 (259)
- August 2022 (367)
- July 2022 (368)
- June 2022 (277)
-
Categories
- 1
- 1 NUCLEAR ISSUES
- business and costs
- climate change
- culture and arts
- ENERGY
- environment
- health
- history
- indigenous issues
- Legal
- marketing of nuclear
- media
- opposition to nuclear
- PERSONAL STORIES
- politics
- politics international
- Religion and ethics
- safety
- secrets,lies and civil liberties
- spinbuster
- technology
- Uranium
- wastes
- weapons and war
- Women
- 2 WORLD
- ACTION
- AFRICA
- AUSTRALIA
- Christina's notes
- Christina's themes
- culture and arts
- Fuk 2022
- Fuk 2023
- Fukushima 2017
- Fukushima 2018
- fukushima 2019
- Fukushima 2020
- Fukushima 2021
- general
- global warming
- Humour (God we need it)
- Nuclear
- RARE EARTHS
- Reference
- resources – print
- Resources -audiovicual
- World
- World Nuclear
- YouTube
-
RSS
Entries RSS
Comments RSS
nuclear-news 