Fukushima's "Swimming Robot" Captures First Images Of 'Massive Deposits' Of Melted Nuclear Fuel

The “Little Sunfish,” the swimming robot that TEPCO is using to capture images of the containment vessel in the Unit 3 reactor of the ruined Fukushima power plant, has brought back the goods.

A trove of new images captured in the past few days show what is likely to be melted nuclear fuel from inside the reactor, what Bloomberg describes as a “potential milestone” in the cleanup of one of the worst atomic disasters in history.

The pictures show what looks to be the melted nuclear fuel that caused the worst-ever nuclear disaster when northeastern Japan was hit by a massive earthquake and tsunami in March 2011. If confirmed, these would be the first discovery of the fuel, which is being sought by TEPCO as part of the cleanup effort.

Tokyo Electric Power Co. Holdings Inc., Japan’s biggest utility, released images on Saturday of mounds of black rock and sand-like substances at the bottom of the No. 3 reactor containment vessel at Fukushima, which is likely to contain melted fuel, according to Takahiro Kimoto, an official at the company. A survey on Friday found black icicles hanging from the above pressure vessel, which was “highly likely” to contain melted fuel. Kimoto noted it would take time to confirm whether this debris contains melted fuel.

 

'The pictures that we have gained will assist us in devising a plan for removing the melted fuel,' Kimoto told reporters Saturday night in Tokyo. 'Taking pictures of how debris scattered inside of the reactor was a big accomplishment.'

 

If confirmed, these pictures would be the first discovery of the fuel that melted during the triple reactor accident at Fukushima six years ago. For Tokyo Electric, which bears most of the cleanup costs, the discovery would help the utility design a way to remove the highly-radioactive material.”

The pictures were taken by the “Little Sunfish,” the Toshiba-designed robot the company sent into the destroyed reactors to explore the inside of the reactor for the first time from July 19. The robot, 30 centimeters (12 inches) long that can swim in the flooded unit, was tasked with surveying the damage inside and also finding the location of corium, which is a mixture of the atomic fuel rods and other structural materials that forms after a meltdown.

“It is important to know the exact locations and the physical, chemical, radiological forms of the corium to develop the necessary engineering defueling plans for the safe removal of the radioactive materials,” said Lake Barrett, a former official at the U.S. Nuclear Regulatory Commission who was involved with the cleanup at the Three Mile Island nuclear power plant in the U.S.

 

“The recent investigation results are significant early signs of progress on the long road ahead.”

Until now, TEPCO hasn’t managed to find the melted fuel, presenting a major obstacle in the cleanup effort, where the removal of the fuel is considered one of the most difficult steps. Sightings of what was believed to be the destroyed fuel in reactors No. 1 and No.2 proved to be inaccurate.

“Similar to the latest findings in the No. 3 reactor, Tepco took photographs in January of what appeared to be black residue covering a grate under the Fukushima Dai-Ichi No. 2 reactor, which was speculated to have been melted fuel. However, a follow-up survey by another Toshiba-designed robot in February failed to confirm the location of any melted fuel in the reactor after it got stuck in debris.

 

A robot designed by Hitachi-GE Nuclear Energy Ltd. also failed to find any melted fuel during its probe of the No. 1 reactor in March.”

The significance of the recent finding “might be evidence that the robots used by TEPCO can now deal with the higher radiation levels, at least for periods of time that allow them to search parts of the reactor that are more likely to contain fuel debris,” M.V. Ramana, professor at the Liu Institute for Global Issues at the University of British Columbia, said by email.

“If some of these fragments can be brought out of the reactor and studied, it would allow nuclear engineers and scientists to better model what happened during the accident.”

According to Bloomberg, because of the high radioactivity levels inside the reactor, only specially designed robots can probe the unit. And the unprecedented nature of the Fukushima disaster means that the utility is pinning its efforts on technology not yet invented to get the melted fuel out of the reactors.

The budget for the cleanup, which is still running behind schedule, has more than doubled to a whopping $188 billion last year. TEPCO has also not been able to decide on what to do with the 777,000 tons of water contaminated with tritium when it was used to cool down the plant’s cores, and has petitioned Japan’s government to allow it to dump some of the water into the Pacific. According to the officials, tritium is not harmful in small doses. It’s believed that the decommissioning of the reactors will cost 8 trillion yen ($72 billion), according to an estimate in December from the Ministry of Economy, Trade and Industry, and take as long as 40 years.

Comments

EuroPox Stuck on Zero Sun, 07/23/2017 - 20:37 Permalink

Or use automatic tunnel boring machines to excavate a huge cavern below the power plant (deep enough to avoid all the underground streams); drop the plant into the cavern and then top it with a concrete plug.  We have the tech to do that sort of job but removing the fuel... it has taken 6 years and they still aren't sure they even have a picture of it!  

In reply to by Stuck on Zero

Manthong johngaltfla Sun, 07/23/2017 - 21:14 Permalink

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  A scaled-up version of those things should come in handy when Steven Hawking’s prediction of the earth turning into Venus comes true.

In reply to by johngaltfla

FoggyWorld EuroPox Sun, 07/23/2017 - 21:23 Permalink

The Russians did try to do a very deep boring and it's today called the Kola Boring.   Worth googling because it's quite a story.  They did get down past 4 miles but the heat exceeded 180 degrees and with that and after spending many years on the project, they abandoned it in the mid 90's. And it wasn't done for military reasons or for searching for petroleum or other resources, but was a genuine scientific project developed to see if they could learn more about what this globe is made of.  Very little really is understood even now about the core of the earth which they got not close to at all.  And they did bring up samples and some web sites show photos. 

In reply to by EuroPox

logicalman EuroPox Sun, 07/23/2017 - 21:36 Permalink

Modern concrete doesn't last even close to long enough to contain this shit adequately, especially wet.Might give some breathing space, though, especially with a decent addition of Boron to absorb a lot of the neutrons that would otherwise be flying about making a whole zoo of nastiness.

In reply to by EuroPox

TeraByte EuroPox Sun, 07/23/2017 - 22:13 Permalink

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A tunnel in the fault line area is not a safe long term storage option.

In reply to by EuroPox

FoggyWorld SilverRoofer Sun, 07/23/2017 - 20:57 Permalink

Those previous two sort of walked around and now they are using what really is a drone that can take being under water and can float.   One person outside guides the critter around and another is focusing the camera.  And they must have upgraded the electronics because the first two just got burned out quickly where this one seems to be a bit more useful.But neither design is that of a robot.  They both require human beings to tell them what to do and to then operate the camera and light. 

In reply to by SilverRoofer

cookies anyone gmak Mon, 07/24/2017 - 04:49 Permalink

why oh why are the sheeple so stupid? Who or what survived you idiotic piece of shit? There are still islands in the bikini atoll that can not be visited for more than a couple of hours. The atoll is one of the most toxic places on the face of the earth. There is no justification for illiteracy. You will eat what you deserve...

In reply to by gmak

put a kettle on Sun, 07/23/2017 - 20:21 Permalink

This is going to take decades to clean-up and contain and I imagine it will be some kind of exclusion zone forever, like Chernobyl. We're so busy erecting monuments to our own hubris all over the world, the aliens that find the husks of civilization we leave behind will think we were so fucking dumb.

logicalman Moe Howard Sun, 07/23/2017 - 20:47 Permalink

Here's a scary one that was so well ignored that hardly anyone knows about.Maybe this explains why there's so much cancer for big pharma to profit from, added to everything else.1957 - Windscale fire UK - was uiranium & graphite - burned for 16 hours.1979 - Three Mile Island US1986 Chernobyl - another burning graphite reactor.The radiological disasters that are old uranium mines, the likes of Hanford, Oak Ridge ....It's a long list and, coincidentally???, cancer rates are on the up and up.When it comes to nuke plants, the spent fuel pools are rarely mentioned, but they are at least as nasty as the cores.This was all about bombs. The only way to sell the nuke concept to the public was to say it would produce almost unlimited, cheap power. Another huge lie.Face it, we're fucked.  

In reply to by Moe Howard

are we there yet Sun, 07/23/2017 - 20:28 Permalink

The price difference between North Pacific wild salmon and Norwegian wild salmon is a good sign people are aware of the radiation problem for a top of the food chain fish.

Utopia Planitia Sun, 07/23/2017 - 20:39 Permalink

This won't get cleaned up for decades (or millenia) just like in the USA because:  It is more valuable to keep it a problem than it is to clean it up.  Hanford could have been completely cleaned up by 1985 if it were not a powerful magnet for two groups of people:  Those whose entire life is dedicated to stirring the pot and labor unions who want to keep thousands of union jobs running for hudreds of years. It is a multi-lifetime pension for all of them.