Shikoku Electric restarts Ikata nuclear reactor following failed court challenges

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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.
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New reactor being built in western Japan applies for safety checks

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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

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“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

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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.
 

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.
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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
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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
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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.