Greater than seven years have handed since a monsterand triggered what grew to become, after Chernobyl, the worst nuclear catastrophe in historical past on the Fukushima Daiichi Nuclear Energy Plant.
When three of its six reactors melted down, scorching gasoline turned to molten lava. And burned by metal partitions and concrete flooring. To today nobody is aware of precisely the place contained in the reactor buildings the gasoline is. And it’s so lethal, no human can go inside to search for it. So the Japanese firm that owns the crippled plant has turned to robots.
There are four-legged robots, robots that climb stairs and even robots that may swim into reactors flooded with water. They’re outfitted with 3D scanners, sensors and cameras that map the terrain, measure radiation ranges and search for the lacking gasoline.
That is a part of an enormous clear up that is anticipated to price practically $200 billion and take many years.
Lesley Stahl: Has something like this cleanup, by way of the scope, ever occurred earlier than?
Lake Barrett: No, this can be a distinctive state of affairs right here. It is by no means occurred in human historical past. It is a problem we have by no means had earlier than.
“It was actually Hell on Earth.”
Lake Barrett is a nuclear engineer and former Division of Vitality official who oversaw the cleanup of the worst nuclear accident in U.S. historical past, Three Mile Island. He was employed as a senior adviser by TEPCO, the Tokyo Electrical Energy Firm that owns the plant and is in command of the trouble to search out the lacking gasoline.
He is additionally advising on the event of recent robots like this six-legged spider robotic that engineers are designing to hold from scaffolding and climb onto tools. He describes them as…
Lake Barrett: Very superior working robots that may really be those with lengthy, muscular arms and laser cutters and such that may go in and really take the molten gasoline and put it in an engineered canister and retrieve it.
Lesley Stahl: Ought to we consider this as a undertaking like sending somebody to the moon?
Lake Barrett: It is even an even bigger undertaking for my part. However there is a will right here to wash this up as there was a will to place a person on the moon. And these engineering duties might be carried out efficiently.
Lesley Stahl: Why not simply bury this place? Why not do what they did at Chernobyl? Simply cowl it up, bury it, and simply go away it right here all– , enclosed?
Lake Barrett: Primary that is proper subsequent to the ocean. We’re 100 yards from the ocean. We have now typhoons right here in Japan. That is additionally a excessive earthquake zone. And there is gonna be future earthquakes. So these are unknowns that the Japanese and nobody desires to cope with.
The earthquake that precipitated the meltdown measured 9.0, Essentially the most highly effective ever recorded in Japan and triggered a sequence of tsunami waves that swept away vehicles, homes and whole cities. Killing greater than 15,000 folks.
At Fukushima Daiichi, the large waves washed over the plant, flooding the reactors and knocking out energy to the cooling pumps that had saved the reactor cores from overheating. Lake Barrett took us to a hill overlooking the reactors the place the radiation ranges are nonetheless comparatively excessive.
Lesley Stahl: So that is really proper where– the place all of it occurred? The guts of the catastrophe, proper right here?
Lake Barrett: Appropriate. There’s reactor primary, reactor quantity two, reactor quantity three. And when the earthquake occurred, 100 miles away, these buildings all shook and these towers all shook. However the design was such that they had been secure. However 45 minutes later, waves had been racing in, tsunami waves, from the earthquake, and there have been seven waves that got here in at 45 ft excessive. And put the station in what we name “station blackout.” They’d no energy. And the cores acquired hotter inside, and warmer, and warmer once more till the uranium began to soften.
Lesley Stahl: What number of tons of radioactive waste was developed right here?
Lake Barrett: Most likely 500 to 1,000 tons in every constructing.
Lesley Stahl: So how lengthy will it’s deadly?
Lake Barrett: It is going to be deadly for hundreds of years.
Lesley Stahl: What we’re speaking about actually is three meltdowns?
Lake Barrett: Sure. It was actually Hell on Earth.
“Nobody is gonna ship a employee in there as a result of they’d be overexposed in only a matter of seconds.”
The meltdowns triggered enormous explosions that despatched plumes of radioactive particles into the environment, forcing the evacuation of everybody inside a 12-mile radius – about 160,000 folks in all. Weeks later, TEPCO officers engaged in so-called kowtow diplomacy – permitting townspeople to berate them as they prostrated themselves in apology.
Hundreds of staff had been despatched to the countryside to decontaminate every thing touched by radiation together with digging up grime and placing it in luggage – plenty of luggage.
However whereas a lot of the evacuation zone has been decontaminated,silent and lifeless with radiation ranges that stay too excessive.
On the plant they’re capturing contaminated groundwater, about 150 tons a day, and storing it in tanks, so far as the attention can see.
Lake Barrett: Water is all the time the main problem right here. And it’ll stay a significant problem till your entire cores are eliminated.
The nearer staff get to the reactors, the extra protecting gear they must put on, as we found.
We had been zipped into Tyvek coveralls and made to put on two pairs of socks and three pairs of gloves.
Lake Barrett: Okay, we have tape.
Not an inch of pores and skin was uncovered. The layers of safety embrace a masks…
Lesley Stahl: It is a bit of free.
Lake Barrett: We’ll tighten it up.
…That usually fogged up.
Lake Barrett: How do you are feeling?
Lesley Stahl: Good.
And a dosimeter to register the quantity of radiation we might be uncovered to.
We had been prepared for battle. We went with a crew of TEPCO staff to unit three, one of many reactors that melted down on that March day, seven years in the past, that the Japanese name, merely 3/11.
Lesley Stahl: Lake!
Lake Barrett: There you’re, Unit 3.
Lesley Stahl: Watch it. Step.
Lake Barrett: These are defend plates as a result of there’s cesium within the floor.
Within the years because the accident, a lot of the injury to the constructing has been repaired.
But it surely’s nonetheless harmful to spend so much of time right here. We may keep solely 15 minutes.
Lesley Stahl: There’s this quantity I have been seeing, 566.
Lake Barrett: Proper. That is telling you the radiation stage that we’re in. It is pretty excessive right here. That is why we’re gonna be right here a short while.
Lesley Stahl: How shut are you and I, proper this minute, to the core?
Lake Barrett: The– the melted cores are about 70 ft that method.
Lesley Stahl: Seventy from here–
Lake Barrett: From right here.
Lesley Stahl: –is the melted core?
Lake Barrett: Appropriate, that is proper over in right here. We do not know fairly the place aside from it fell down into the ground.
Lesley Stahl: So should you despatched a employee in proper now to search out it, how lengthy would they survive?
Lake Barrett: Nobody is gonna ship a employee in there as a result of they’d be overexposed in only a matter of seconds.
Enter the robots.
Lesley Stahl: That is the robotic analysis middle.
Dr. Kuniaki Kawabata: Sure. That is for distant management expertise improvement.
In 2016, the Japanese authorities opened this $100 million analysis middle close to the plant the place a brand new era of robots is being developed by groups of engineers and scientists from the nation’s prime universities and tech corporations.
Dr. Kuniaki Kawabata is the middle’s principal researcher.
Dr. Kuniaki Kawabata: That is our latest robotic, J-11.
Lesley Stahl: So, quantity 11. And it is an impediment course.
Dr. Kuniaki Kawabata: Sure. the operators use the digicam picture in entrance of the robotic. But it surely’s so many hours required to coach. As a result of it appears very straightforward, nevertheless it’s fairly troublesome.
Additionally they practice right here on this virtual-reality room the place 3D information taken contained in the reactors by the robots is projected onto this display. Operators, utilizing particular glasses, can go the place no people can.
Lesley Stahl: So we’re really strolling through–
Dr. Kuniaki Kawabata: Uh-huh.
Lesley Stahl: –a a part of a reactor.
Dr. Kuniaki Kawabata: Uh-huh. You are feeling some immersive expertise.
Lesley Stahl: Y– in order should you’re in there.
Dr. Kuniaki Kawabata: Sure.
Lesley Stahl: I really wanna duck. I imply, that is how actual it feels to me. Like right here we’re going beneath this factor. I’ve to duck.
Dr. Kuniaki Kawabata: Ah, sure.
However even with all of the high-tech coaching and know-how, the robots have run into issues. For the early fashions, it was the extreme ranges of radiation – that fried their electronics and cameras.
Lake Barrett: Their lifetime was hours. We hoped it might be days, nevertheless it was for hours.
Lesley Stahl: Inform us what occurred to the robotic named Scorpion. It is a extremely refined, and I collect all people thought this was the reply.
Lake Barrett: That was gonna be the primary robotic we had been going to place contained in the containment vessel, which is the place we want the data essentially the most ‘trigger that is the place the core is.
That is Scorpion, whose mission price an estimated $100 million. It was designed to flatten out and slither by slender pipes and passageways on its method to the core. And, like a scorpion, it raises its tail.
Lake Barrett: The tail would provide you with a digicam on prime with lights. As a result of it’s a must to have its personal lights. It is all darkish inside. There’re no common lights. In order that was the plan. And we had nice expectations and hope for that. All of us did. Took a yr to organize, and it was onerous work.
However when Scorpion went inside, it hit some particles and acquired caught after touring lower than 10 ft.
Lesley Stahl: I can not think about the frustration l– ranges.
Lake Barrett: Nicely, however you be taught extra from– from failure generally than you do from success.
They’d extra success with this robotic named Little Sunfish, which was designed to swim inside one of many reactors flooded with water. In getting ready for Little Sunfish’s mission, engineers spent months doing check runs inside this monumental simulation tank, fine-tuning the propellers, cameras, sensors and 65 yards of electrical cable — all constructed to face up to intense ranges of radiation.
They used nuclear reactor quantity 5 to assist plan the mission. It did not soften down when the tsunami hit and is sort of equivalent to the one Little Sunfish would scout. Lastly, final yr, the swimming robotic made its foray into the center of the reactor. To search for the lacking gasoline. Barrett took us into unit 5 to point out us the way it maneuvered by the labyrinth of pipes and particles contained in the reactor.
Lake Barrett: The Little Sunfish got here down on the sting and it swam underwater down by this little entryway right here beneath the reactor vessel.
Lesley Stahl: Is that this the route Little Sunfish took?
Lake Barrett: Sure that is. The Little Sunfish swam through this portal, down into this space, it went across the facet. It went down by this grating, which was gone. We’re standing instantly beneath the reactor vessel. Molten gasoline got here by right here and it jetted out beneath very excessive strain. After which it got here out slowly like a lava in a volcano, and it fell down and burned its method by this grating right down to the ground.
That is what Little Sunfish noticed as technicians guided it by the pipes and hatchways of the flooded inside. It beamed again photographs revealing clumps of particles, gasoline rods, half-destroyed tools and murky glimpses of what appears like solidified lava — the primary indicators, TEPCO officers say, of the lacking gasoline.
Lake Barrett: These robotic steps up to now have been vital steps. However it is just a small step on a really, very lengthy journey.
Lesley Stahl: That is gonna take you stated many years with an “S.” What number of many years?
Lake Barrett: We do not know for certain. The purpose right here is 40– 30– 40 years. , I personally assume it might be even 50– 60, nevertheless it’s–
Lesley Stahl: Oh, perhaps longer.
Lake Barrett: It, effectively, it might be longer. However the actuality is this can be a problem that is by no means been handled earlier than. However each step is a constructive step. You be taught from that and go ahead to a different step.
Produced by Richard Bonin and Ayesha Siddiqi