Removal of fuel in pool at Fukushima’s melted reactor begins

TEPCO to start removing fuel at Fukushima’s No. 3 reactor

Shikoku Electric restarts reactor under post-Fukushima regulations
Ikata nuclear power plant in Ehime Prefecture, is restarted.
After the Tepco Fukushima Daiichi earthquake/tsunami disaster and the Kumamoto recent earthquake, it is to be wondered what Japan has learned?
The Ikata nuclear power plant is located on the Hinagu fault zone and Futagawa fault zone, themselves extension of Japan’s largest active fault “Median Tectonic Line”.
In case of any accident, for the residents living on Sadamisaki Peninsula evacuation would be only possible by boat to Kyushu Island, such evacuation would be therefore difficult, even impossible.
Unless there would be a Japanese Moses to open the sea, such evacuation plan should be referred to as an escape from reality.
The Ikata Nuclear Power Plant in Ikata, Ehime Prefecture
MATSUYAMA, Japan (Kyodo) — Shikoku Electric Power Co. restarted a reactor at its Ikata power plant in western Japan on Friday, making it the fifth unit reactivated under tougher regulations set following the 2011 Fukushima nuclear disaster.
The No. 3 reactor at the plant in Ehime Prefecture is the only restarted unit in Japan that runs on uranium-plutonium mixed oxide, or MOX, fuel, as a court ordered Kansai Electric Power Co. in March to suspend two reactors at its Takahama plant after they resumed operations earlier this year, citing safety concerns.
MOX fuel, created from plutonium and uranium extracted from spent fuel, is a key component of the nuclear fuel recycle program pursued by the nuclear power industry and the government.
The government aims to bring reactors back online after the Fukushima crisis led to a nationwide halt of nuclear plants, as it plans to have nuclear power account for 20 to 22 percent of the country’s total electricity supply in 2030 to cut greenhouse emissions and lower imported fuel costs.
The Ikata unit is expected to reach criticality, or a state of sustained nuclear chain reaction, on Saturday and begin generating and transmitting electricity on Monday before resuming commercial operation in early September for the first time since it was halted in April 2011 for regular inspection.
“We will take steps toward criticality and resumption of power generation with priority on ensuring safety,” Shikoku Electric President Hayato Saeki said in a statement on Friday.
Meanwhile, around 70 residents and others opposing the reactor restart gathered around the seaside plant early Friday morning, chanting slogans such as “Don’t contaminate the Seto Inland Sea,” and “Stop the nuclear plant.”
Junko Saima, a 72-year-old woman from Yawatahama, adjacent to the town hosting the plant, which is located on one side of a narrow peninsula, said, “I am nervous that some kind of accident may occur.”
Opponents are concerned about the effectiveness of government-prepared evacuation plans in case of an accident and about potential major earthquakes that are not taken into account in the plans, while proponents are hailing the resumption as it could bring economic benefits.
The restart follows the reactivation of two reactors at Kyushu Electric Power Co.’s Sendai plant in Kagoshima Prefecture last year and the brief run of the Nos. 3 and 4 units at Kansai Electric’s Takahama complex in Fukui Prefecture.
The mayor of Ikata town and the governor of Ehime Prefecture have already given their consent to restart the No.3 reactor after regulators approved its restart in July last year.
In June, Shikoku Electric loaded nuclear fuel at the power plant eyeing to reboot it on July 26. However, reactivation was postponed due to problems with the reactor’s cooling system.
A group of local residents filed a suit in May seeking an injunction to halt the restart arguing that a series of earthquakes that have hit nearby Kyushu Island in April could trigger quakes along the median tectonic line running close to the Ikata reactor.
The plant is about 170 kilometers east of Kumamoto Prefecture, the epicenter of the quakes.
Meanwhile, in Kagoshima, new Gov. Satoshi Mitazono is planning to ask Kyushu Electric to suspend the two reactivated reactors at the Sendai plant to double-check any safety impact on the units from the powerful earthquakes that hit neighboring Kumamoto in April.
http://mainichi.jp/english/articles/20160812/p2g/00m/0dm/035000c
Tepco investigated equipment hatch of Reactor 3 PCV / “Next time, use robot with a smartphone”
On 9/9/2015, Tepco investigated the equipment hatch of PCV 3 (Reactor 3 PCV) with a portable camera.
They reported the hatch is not leaking coolant water from the inside of PCV 3, nor was damaged however the floor was wet and didn’t confirm where the water was leaking.
None of the atmospheric dose or nuclide analysis data was released. On the other hand, the video shows the white noise caused by extremely high level of radiation.
Considering what they have found in this investigation, Tepco is to decide to send a remote-controlling robot for the next phase. The robot is planned to carry a “smartphone camera” for some reason.
The plan image of the new robot to investigate inside PCV 3. A smartphone is used as its camera.
http://www.tepco.co.jp/nu/fukushima-np/handouts/2015/images/handouts_150909_12-j.pdf
http://photo.tepco.co.jp/date/2015/201509-j/150909-03j.html
Source: Fukushima Diary
Tepco readies to install unit 3 cover
From World Nuclear News, a pro-nuclear website
The installation of a protective cover over unit 3 of the damaged Fukushima Daiichi plant in Japan can start as soon as the removal of rubble from the reactor building is completed, Tokyo Electric Power Company (Tepco) said.
Plans were announced in November 2012 for a cover to be constructed to encase the unit’s damaged reactor building, protecting it from the weather and preventing any release of radioactive particles during decommissioning work.
The section of the reactor building that sheltered the service floor of unit 3 was wrecked by a hydrogen explosion three days after the tsunami of March 2011 – leaving the fuel pond exposed and covered by debris including many twisted steel beams.
The fabrication of the cover has been under way since November 2013 at the Onahama works in Iwaki city. It has been made in sections so that once it is transported to Fukushima Daiichi, the time to assemble it can be shortened and the radiation exposure to the workers on site can be significantly reduced, Tepco said.
A separate structure will be built to facilitate the removal by crane of used fuel from the storage pool. This 54-metre-tall structure will include a steel frame, filtered ventilation and an arched section at its top to accommodate the crane. Measuring 57 metres long and 19 metres wide, it will not be fixed to the reactor building itself, but will be supported on the ground on one side, and against the turbine building on the other.
On 2 August, Tepco announced that it had removed the fuel handling machine, the largest remaining piece of rubble, from the unit’s used fuel pool at the top of its reactor building. Its removal followed months of preparation and clears the way for the remaining rubble and the used fuel in the storage pool to be removed.
The assembly of the protective cover over unit 3 will start once all the rubble is removed.
Tepco said there are a total of 566 fuel assemblies inside the unit’s pool and the cover will prevent radioactive substances from scattering during their removal.
The fuel removed from unit 3 will be packaged for transport the short distance to the site’s communal fuel storage pool, although it will need to be inspected and flushed clean of dust and debris.
Source: World Nuclear News
http://www.world-nuclear-news.org/RS-Tepco-readies-to-install-unit-3-cover-1308155.html
Removal of debris in reactor 3 spent fuel storage to start
Workers at the Fukushima Daiichi nuclear power plant on Sunday will start the removal of a fuel exchanger inside the Number 3 reactor building. The 20-ton device fell into the fuel pool during the 2011 disaster.
The device has since been a major obstacle for workers at Tokyo Electric Power Company in the start of removal of extremely radioactive rubble left in the storage pool. 566 fuel rods remain inside the spent fuel pool.
Workers cannot directly take part in the process as the site is highly radioactive. The work will require 2 remote-controlled cranes that will lift and remove the device, which is some 14 meters long.
The work poses a challenge as spent fuel may suffer damage if the device falls back into the pool during removal.
Workers accidentally dropped a 400-kilogram device into the pool last August. Though none of the rods suffered damage, removal was postponed for 4 months.
TEPCO has been preparing for the removal by developing equipment tailored to grip the device. Cushions have also been placed on top of the fuel rods.
TEPCO officials say all other work to decommission the plant will be suspended while the removal takes place as a hydrogen explosion in 2011 left the pool without a roof.
Source : NHK
http://www3.nhk.or.jp/nhkworld/english/news/20150730_05.html
Strontium-90 detected in potentially discharged water from Reactor 1 and 3
October 20, 2014
2,800 ~ 11,000 Bq/m3 of Strontium-90 have been detected from pumped water around Reactor 1 and 3, according to Tepco.
On 10/1/2014, Tepco released nuclide analysis data of groundwater. The tested groundwater was pumped up from the facilities called “sub-drain” located beside Reactor 1 ~ 4.
These “sub-drains” were originally to reduce groundwater volume to flow into the basement of each reactor building, however abandoned because of the high level of contamination after 311. Tepco is trying to restart using these sub-drains to pump up highly contaminated water and to discharge to the sea.
(cf, Tepco to pump up highly contaminated groundwater for potential discharge today / Drainage plan submitted to NRA.
The samples were taken this September and last September. From the sample near Reactor 1, 11,000 Bq/m3 of Strontium-90 was detected last September. From the sample near Reactor 3, 2,800 Bq/m3 of Strontium-90 was measured this September.
These readings were not checked by third party organizations, so the actual density can be higher than announced.
Either way, the data shows groundwater contamination is spreading from around the reactor buildings to the outside of the port. (cf, Strontium-90 detected outside of Fukushima port / Highest reading in front of Reactor 4 too.
Source: Fukushimary Diary
http://fukushima-diary.com/2014/10/strontium-90-detected-potentially-discharged-water-reactor-1-3/
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