Video footage has been released of the swimming robot Little Sunfish's finds inside reactor 3 of Fukushima No. 1 Nuclear power Plant. Three separate videos showing short portions over the three-day investigation can be seen below. In the first, the robot can be seen entering the reactor while the second and third contain imagery of the branch-like matter that is believed to contain the solidified remnants of the melted nuclear fuel debris.
Images captured by the Little Sunfish robot between July 19 and July 21 of the inside of reactor 3 at Fukushima No.1 Nuclear Power Plant. The branchlike structures at upper left of the lower, larger image (and the lower left corner of the 4th image in the gallery) is thought by plant operator TEPCO to be nuclear fuel debris that melted to the bottom of the reactor following the March 2011 nuclear disasters at the plant. Other materials in the photos are thought to be various components of the reactor that melted and collected at the bottom of the reactor vessel - a solidified melted mush sometimes referred to as corium. The oval dial-like component pictured top left, is said to be a part of the reactor's control rod mechanism. All images: TEPCO
Stricken Fukushima nuclear plant operator TEPCO is now claiming that recent images captured by the swimming robot that entered the plant's No. 3 reactor may well show huge deposits at the bottom of the reactor that include clumps of melted nuclear fuel.
TEPCO official Takahiro Kimoto announced late Friday that some of the images taken by the Little Sunfish robot, which began investigations inside reactor 3 at Fukushima No. 1 Nuclear power plant on July 19, showed clumps resembling solidified lava-like rock that may prove to be remnants of the nuclear fuel.
Kimoto said at a press conference in Tokyo that this is the first time "such clear images of what could be melted fuel” have been taken. “We believe that the fuel melted and mixed with the metal directly underneath it," he added. "It is highly likely that we have filmed that on Friday.”
The fragments pictured are thought to be located among rubble collected at the bottom go the reactor that measure as much as 2 meters in depth. The rubble is located at the base of a structure called the pedestal, which sits underneath the core inside the reactor's primary containment vessel.
Images of what was thought to be melted fuel debris were first noticed on Friday and the search for confirmation continued Saturday, the final day of the Little Sunfish's three-day probe inside reactor 3. There was, however, some confusion in reports about how the pictured nuclear fuel appeared, some saying it was in large clumps, others that it was hanging in icicle-like shards.
Previous searches for melted fuel debris inside two of the other destroyed reactors, (reactors 1 and 2), produced inconclusive results, and further analysis of the imagery collected this time will be required to gain conclusive evidence that it is in fact melted fuel. At present it remains little more than speculation by TEPCO that it is in fact fuel debris.
Locating the fuel debris in the plant’s three wrecked reactors is said to be a crucial step in the decommissioning of the Fukushima plant, a process that is estimated to take up to 40 years. Without such location and analysis the removal of the highly radioactive fuel will be hazardous, especially as the reactors are in such a damaged, treacherous state only accessible by robots. A novel method to remove the fuel debris was recently reported as being presented by a company helping with the decommissioning process.
One thing that has become clear from this recent find is that, should indeed the fuel debris be a part of the matter shown in the pictures, extracting it from the reactor could be an even more complex process than originally thought. Shown among the items that have ended up in the bottom of the vessel and are mixed up with what is claimed to be the fuel debris are metal components of the grid used to keep the reactor's control rods in position.
In other Fukushima related news, TEPCO's announcement last week that it plans to dump more than huge amounts of radioactive water into the Pacific Ocean has caused a stir among residents.
Fishermen and other residents in Fukushima have expressed concern about the planned dumping of 770,000 tons of contaminated water into the sea, saying the announcement is premature and first requires the green light from government and other official bodies.
Source: TEPCO, NHK, Mainichi
Fukushima No. 1 Nuclear Power Plant operator TEPCO has announced that the 30 cm long, 2 kg underwater robot "Little Sunfish" has been deployed inside Fukushima Daiichi’s No. 3 reactor.
It's mission is to inspect the damage inside the reactor and locate parts of melted fuel believed to have fallen to the bottom of the chamber following the meltdown that occurred there in March 2011.
So far nothing of note has been found, though spokesperson said the robot had captured views of the underwater damage that had not been previously seen.
More to follow
TechCrunch features an interesting article about an ever-evolving robot that can "save lives" and has new features that were developed with the Fukushima nuclear crisis in mind. MIT's Cheetah is described as a four-legged robot that can run, autonomously, at speeds of up to 14 miles per hour, jump over obstacles and respond to instructions when performing search and rescue operations. In its latest iteration, the Cheetah 3, it can also help in a nuclear crisis. “Our vision changed to wanting to use this in a real situation, to dispatch it to Fukushima,” professor Sang-bae Kim of MIT's Biometrics Lab told TechCrunch. “We want to use this in a place where we don’t want to use humans." Full article here. Meanwhile, the MIT video below shows the Cheetah 2 in full flight.
Let's hope it has more success than some of the robotics developed to deal with the Fukushima crisis to date.
Video: Haewon Park, Patrick Wensing and Sangbae Kim
Stricken Fukushima No. 1 Nuclear Power Plant operator TEPCO has confirmed its intentions to dump hundreds of thousands of tons of radioactive water into the Pacific Ocean, despite protests from local fisheries groups, residents and other opposition groups.
More than three-quarters of a million tons of contaminated water will be dumped into the Pacific in an attempt to move ahead in the faltering three-stage, 40-year decommissioning road map of the Fukushima plant, which experienced multiple explosions and meltdowns following the March 11, 2011 earthquake and tsunami in northern Japan.
Since the disasters, when radiation emitting from the plant forced the evacuation of more than 150,000 residents, the plant has been plagued by ground water and other technical problems, which has led to contaminated water being stored onsite in tens of thousands of tanks.
Nuclear Regulation Authority chairman Shunichi Tanaka recently questioned the utility's commitment in decommissioning the plant, calling for a controlled release of the water, which now exceeds 770,000 metric tons. While TEPCO had rejected this proposal due to fears of a public backlash, chairman Takeshi Kawamura said it was now felt that the dumping of the contaminated water was a necessary step to show the kind of positive intent by the utility that had previously been lacking.
"Technically, we fully support the (NRA) chairman's proposal," Kawamura said yesterday, adding that there is still strong resistance from local residents, especially fishermen. "I think we should have acted sooner. ... We should start moving faster."
The contaminated water, some of which has been recycled to continue cooling the stricken reactors, has been filtered via a processing system known as ALPS, a $150-million system that reportedly strips the water of cesium and 61 other dangerous isotopes to reduce contamination to levels considered safe enough to dump into the sea. A myriad of technical problems meant this system has largely been offline since the disasters, and TEPCO has been forced to employ other more established filtering systems, such as one developed in the US that only removes strontium from contaminated water.
As of early, 2017, more than 1 million tons of contaminated water was being stored at the plant. Some of it has been recycled to be re-circulated through the reactors in an effort to maintain cooling, while the rest has been left standing in massive tanks.
While researching “Yoshida’s Dilemma,” Lake Barrett, a former head of the US Department of Energy’s Office of Civilian Nuclear Waste Management who was part of the early mitigation efforts following the Three Mile Island nuclear accident in the US, said as early as 2013 that storage of contaminated water onsite was “unsustainable,” meaning it would ultimately need to be dumped into the Pacific.
“There needs to be a better focus starting with TEPCO in explaining things … because I think the psychological worry is real and people have already been traumatized, and in my view do not deserve to be traumatized any more,” said Barrett, who was taken on by TEPCO as a groundwater specialist to fill a significant gap among the utility’s 40,000 employees. However, he played down the significance of the contaminated water issue. “In my scientific view, much of the concern (about the contaminated water) is overstated.”
One of the problems faced by the utility in the dumping process, which Barrett and other nuclear experts say is not unusual at nuclear plants, is that one contaminant, tritium, is impossible to filter out by the ALPS system.
As early as March 2016, TEPCO inferred it would start releasing the water into the ocean during that year. Even then, Barrett and other pro-nuclear commentators, backed up by a Canadian academic study, claimed that levels of the only isotope remaining in the stored water after treatment, tritium, “are not a meaningful health risk.”
Indeed, the NRA’s Tanaka also commented that year that the levels of tritium in Fukushima's tanks was so weak that its radioactivity “won’t penetrate plastic wrapping."
Today TEPCO commented on its website that it agreed with Tanaka that "in light of the current scientific and technically based regulations and standards, the release of tritium into the Ocean would not be a problem."
However, Shaun Burnie, a senior nuclear specialist with Greenpeace, disagrees, saying tritium is a “relatively hazardous” isotope, whose beta particles inside the human body are more harmful than most X-rays and gamma rays. Furthermore, organically bound tritium absorbed by marine life and humans presents “an additional risk,” Burnie says, adding “major uncertainties” in the long-term effects posed by radioactive tritium means “the planned release of billions of becquerels by TEPCO cannot be considered an action without risk to the marine environment and human health.”
Burnie also claims that the ALPS treatment has not completely eliminated all of the other radionuclides, such as strontium and cesium.
It is such concerns that have led to widespread objections to the release of the water by local residents, especially fishermen, who say their industry has suffered enough from the nuclear accident, which has had a multi-billion dollar impact on the local economy. The dumping of the water and negative publicity it would generate would devastate the economy still further, they say.
Nonetheless Kawamura says “the decision has already been made" to dump the contaminated water, according to a report in The Japan Times. Despite that claim, Kawamura suggested that TEPCO will wait for the government investigation panel’s final decision before going ahead with the water dumping.
“We cannot keep going if we do not have the support of the state,” he said.
In its release on Friday, TEPCO also stated that it needed the understanding of people. The dumping was not a final decision and that the safety and recovery of the Fukushima people would first need to be "carefully considered."
Since the 2011 nuclear disasters, tens of thousands of tons of contaminated water has already leaked into the Pacific, something that TEPCO at first covered up but since 2013 even Fukushima power plant chief Masao Yoshida has admitted to. Traces of radiation, including caesium, from the plant have been found as far away as California. In that same year typhoons inundated the plant causing the operator to release around 1,100 tons of contaminated water that could now be contained into the ground.
Even since the construction of the tanks to keep the water a catalog of mishaps have occurred at the plant, including leaks from the tanks themselves, leaks that even the subcontractor charged with building them had warned was destined to happen. The first of those leaks amounted to 100 tons of highly radioactive water that was eventually shown to have overflowed after a valve was left open by mistake, while a second leakage was down to workers overfilling a tank with contaminated water.
During a March 2014 visit to the Fukushima No. 1 plant, which I attended, former US Nuclear Regulatory Commission chair Dale Klein said such indiscretions by TEPCO have not helped with the all-important mission of disposing of the water. “There is progress being made … (but) one of the frustrating things that happens is that TEPCO will take five steps forward and then two steps back.”
Sources: Tokyo Shimbun, TEPCO, Yoshida's Dilemma
Renewables company Infini last week marked the completion of a new solar panel manufacturing plant in Fukushima, whose capacity could rise to 300 MW and reportedly increasing clean energy investment in the second quarter (Q2) of 2017 in Japan to US $2.9 billion.
Infini will produce crystalline silicon solar photovoltaic panels for the domestic market at the new factory, which is located in Naraha Town, one of the municipalities most seriously affected by the March 2011 nuclear accident in Fukushima Prefecture. The facility will have an initial capacity of 100 MW though Infini plans to triple that capacity at a later stage and export the products to other markets.
Meanwhile Yamaka Electric Construction Co. has also announced the completion of three solar power plants, all of which are located in the Tohoku region that was devastated by the March 11 2011 megaquake and tsunami, which triggered the Fukushima nuclear disaster. The plants, in Miyagi, Iwate and Fukushima prefectures, have a combined capacity of 46 MW.
Additionally, NTT Facilities Inc. in conjunction with Kitashiba Electric Co. will build a 14 MW solar plant that will commence operations next fall in Minamisoma, a city also in Fukushima.
Japan plans to add 28 Gigawatts of solar capacity by 2020 — the year it hosts the Tokyo Olympic Games. This is a part of efforts to promote use of renewable energy sources, though the country has been sending out mixed signals regarding this intent in recent years. A notable change for the better is the increasing and significant presence of PV panels within the grounds of Japan’s regional airports and other public facilities with large areas of dead space.
Also making the news over the past couple of days is Japanese trading firm Marubeni Corp., which commenced commercial operations of a 37-MW biomass plant running on imported wood chips in Tsuruga City, western Japan.
The energy generated generate will be sufficient to power some 70,000 local homes and is one of Marubeni’s 18 renewable energy projects in Japan.
Global clean energy investment in Q2 of 2017 rose 21% over Q1 to USD 64.8 billion, down 12% over 2016 Q2. Japan’s 12% rise in the quarter was modest compared with Mexico (up 261% to $1.8 billion) and Sweden (213% to $887 million) though significantly better than others, including the UK (down 93% to $407 million), Germany ( down 34% to $3.2 billion) and China (-16% to $23.3 billion).
The Japanese government's aim is to have renewable energy account for 22-24% of Japan's total power mix by fiscal 2030. At present, that figure stands at roughly 7.5%, according to Japan for Sustainability data. The top renewable energy source in the country is solar power (with a 3.3% share of the total mix) and should the 2030 target be met, Japan’s installed PV capacity will hit 64 GW. .Japan's current solar power production is around 30 GW.
The head of Japan's nuclear regulator says he feels "a sense of danger" over Fukushima nuclear plant operator TEPCO's ability to decommission the stricken plant and manage the utility's other reactors.
During a meeting with TEPCO's top executives, Japan's Nuclear Regulation Authority chairperson Shunichi Tanaka, expressed doubts about the utility's commitment to decommission the Fukushima No. 1 Nuclear Power Plant, which experienced multiple explosions and reactor meltdowns following the March 2011 earthquakes and tsunami that devastated a large area of northeastern Japan.
Tanaka said that officials at Tokyo Electric Power Co. (TEPCO) do not seem "to have the will" to take the necessary moves toward decommissioning the stricken plant, which has hit upon numerous problems during the first stage of a three-part decommissioning plan, which in total is estimated to take around 40 years to complete.
The NRA chief also questioned TEPCO's ability to adequately manage its other nuclear facilities, in particular the Kashiwazaki-Kariwa plant in Niigata Prefecture. TEPCO has requested the green light to resume operations at the plant's no. 6 and no. 7 reactors in an attempt to finance massive compensation payouts related to the Fukushima disaster, which resulted in the evacuation of more than 150,000 residents living near the plant. Among the compensation costs faced by the utility is a multi-million dollar lawsuit by US navy personnel who were irradiated by poisonous leaks from the plant as they anchored off Japan's Pacific coast following relief operations in the disaster region.
Despite the Niigata plant having cleared the necessary safety upgrades imposed following the Fukushima disaster, Tanaka expressed his doubts during a meeting with TEPCO's chairman Takeshi Kawamura and president Tomoaki Kobayakawa, saying "an operator that is lacking the will to take the (decommissioning) initiative does not have the right to resume operation of nuclear reactors."
This is not the first time that Tanaka has criticised TEPCO. In September 2013 he rapped the operator for continuing to put out questionable data on radiation leaks from the Fukushima plant, a situation that he said was causing confusion and a heightened sense of crisis.
"As I've said before, TEPCO has not been properly disclosing the situation about the contamination and the levels of contamination," Tanaka said at the time.
"This has caused confusion domestically and internationally," he addd. "Because of that, the Japanese government has a sense of crisis and I, personally, feel a little angry about it. ... Releasing incorrect information ... has created trouble around the world."
A month later during an NRA meeting Tanaka questioned TEPCO's technical capacity to operate nuclear reactors.
There have been reports of a mystery woman delivering paper bags stuffed with cash to the three prefectures most severely affected by the March 2011 disasters in northern Japan.
The woman, who is thought to be in her 60s, made three separate donations to prefectural offices in Iwate, Miyagi and Fukushima, which were battered by a magnitude 9.1 megaquake and subsequent tsunami on March 11, 2011.
When officials tried to give the lady a receipt she excused herself, saying she had to rush to catch a bus.
Some 18,000 people were killed during the disasters, and hundreds of thousands lost their homes. More than six years on, many remain in temporary housing as reconstruction efforts continue and the decommissioning of the Fukushima No. 1 Nuclear Power Plant, which suffered multiple reactor meltdowns triggered by the tsunami, will take at least 35 years.
Local news has been reporting of a state-backed corporation coming up with a way to decommission Fukushima No. 1 Nuclear Power Plant through an unconventional method that could cause even more radioactive emissions from the the crisis-stricken plant.
The Nuclear Damage Compensation and Decommissioning Facilitation Corp., which was established after the March 2011 crisis to help utility TEPCO with its massive indemnifications, has also been involved with providing technical support for decommissioning the complex. Now, however, it is believed to be on the verge of announcing a method to remove nuclear debris within the three stricken reactors that does away with filling the reactor containment vessels with water.
The method reportedly under consideration is to use drills or lasers to gradually shave off the debris, with water sprayed in remotely.
Normally filling containment vessels with water is considered essential before removing radioactive debris in order to prevent the spread of radiation. An expert who was asked about this new method said that new approaches were important as the conventional approach might prove difficult due to the possibility water may leak from the damaged structures.
The argument about whether or not water “might” leak form the vessels or not is moot -- the ground water issue that has stymied decommissioning progress at the plant is already well known to have been caused by leaks from the reactors. Even officials from Japan’s International Research Institute for Nuclear Decommissioning (IRID) have stated that the vessels are riddled with holes.
“The safest way to remove the fuel is to fill the primary containment vessel with water and … under such a condition maybe the workers can access the fuel debris underwater,” Kazuhiro Suzuki, executive director of IRID, told me while researching “Yoshida’s Dilemma.” However, hundreds of holes and cracks and other damaged components would need to be fixed first, perhaps with the help of robots and a kind of nuclear fuel-proof sealer, he added. “With the high radiation levels, just to fix all of these is very difficult,” he said.
The new method apparently under consideration would mean that some debris would remain in the air during the operation, meaning radioactive materials could fly off into the air.
However, even if the new method should prove to be viable there is still one major hurdle to be cleared first: Finding out exactly where the debris is located.
Previous forays into the reactors using a number of robotic devices developed by IRID and nuclear component developers such as Hitachi have been largely unproductive in clarifying the situation. It is hoped that latest investigation, which is reported to be taking place this month, will make some headway inside reactor 3, though experts are unsure if it will be enough to encourage any concrete plan of debris removal there. The previous investigation, inside reactor 2, was equally inconclusive, though it did prompt TEPCO to announce that radiation inside the reactor is of such a high level as to be life-threatening.
Sources: NHK, Asahi Shinbun, Kyodo