A long steel tube with fiber optics to pipe in light, mirrors and optics to transmit an image down the tube would be infinitely easier. They'd need to burn a few holes, but none of the reactor vessels are intact so that wouldn't allow additional radioactive material to escape.
I'm surprised the Japanese decision to dump the all the tritium contaminated water into the ocean hasn't made more news.
What about the animals you possibly didn't see and how many animals reach fertility in 2-3 years?
https://www.pri.org/stories/2016-04-26/30-years-after-cherno...
It's probably unwise, but it's not super deadly.
With an electronics-free periscope, they could have saved five years. And keep in mind, the radioisotopes are still flowing into the ocean this whole time.
That seems likely to degrade the fiber, or the signal and I'm having trouble thinking of any tested fiber in the range of a molten reactor core. The flux is really crazy near that thing, and not just photons, but relativistic electrons and some very angry helium nuclei.
Or you could put a scintillating detector in a lead ball with a hole, and scan by rotation and pipe the light from the scintillator out to external electronics. All you need is a long pipe installed to get started.
Could you go into more detail?
Oh you mean the dump that had 4 grams of tritium in it?
Not drinking water for sure, but less worrying than it seems at first
https://www.reddit.com/r/worldnews/comments/6nenrd/fukushima...
Radiation shielding is a hard problem. For meaningful reduction of xray and gamma radiation in this environment, we're talking inches of lead cladding [0]. And even that won't ensure a useful lifespan for your fiber, exposed to at least tens of Sv/h along much of its length. And cladding doesn't even begin to address the problem posed by neutron radiation.
The environment in Reactor 2 isn't just hostile to life; it's hostile to organized matter.
http://www.eichrom.com/PDF/gamma-ray-attenuation-white-paper...
Did they consider non-electronics solutions? Who knows. It may be the sooner they discover where the fuel went, the sooner they need to start spending the $80B to dig it out. So slow is a feature.
You absolutely would need cladding on a light pipe, and lots of it. All kinds of optical materials are subject to darkening, clouding, and embrittlement by much lower levels of ionizing radiation than exist in the reactor [0]. Again, here we're talking about tremendous amounts of radiation over much of the pipe's length, so even small amounts of damage per unit length are going to quickly render the pipe useless for imaging.
As for the illumination, collimated light down a polish steel tube would obviously work, but a rod of glass should work as well.
Imaging is a problem. Your search for "refractive elements that would work in the high radiation environment" would likely lead you to something like the optics that Toshiba has developed for these robots. Remember to also account for the thermal effects; radiation of this magnitude is capable of heating the internal elements of your assembly by hundreds of degrees, and your telescope-like camera must maintain its tolerances very precisely to produce a usable image. And perhaps the hardest problem of all: how to maneuver all of this stuff into place through hundreds of meters of industrial hell, where humans can't even stay long in the parking lot outside of a shielded truck. Tackle these problems using no robotics, and you'll be famous, I guarantee it :)
* You can transfer light through such cables. This means you use one cable to send light into the scene and another cable to see to the scene. Please just look up how endoscopy works for many many many decades, long before computers were a thing. (face palm #2) You probably have a SPDIF connector at your home entertainment devices. Have a look at the fiber cable and hold it against a light or look through it, to get the idea. https://en.wikipedia.org/wiki/S/PDIF (it's about a single fiber cable, not a multi-fiber cable that is nowadays more common)
* Endoscopes are operated with wires, mechanical wires operated by a human (or could be by low tech remote pneumatic construct many feets away from the scene) - just look up endoscop (face palm #3)
So a low tech solution would work in such environments, though it's not as news worthy and not as cool as some robots, but it would be useful for a long time, not die at all.
I am surprised by the lacking education here, unfortunately the site got mainstream and attracted average joes from everywhere - with even basic education like in physics and mechanical engineering we could have a proper conversation here. Even CS and startup topics are now littered by corporate drones and fanboys of minor things. Maybe different tags/channels would help to channel the news.
I don't know where you got that idea, but it's very wrong. Optical glasses of all kinds are quite vulnerable to darkening, clouding, and embrittlement by much lower levels of ionizing radiation than those at Fukushima [0].
Even if you shielded the fibers with centimeters of lead, the radiation received along the fiber's length would quickly render it useless for either imaging or lighting. And with that much shielding, good luck moving it around. How exactly do you think you'll get your low-tech thingy into place, maneuvering it hundreds of meters of abandoned building, ruble and industrial wreckage? Remember that you can't even be in the parking lot unless you're in a heavily shielded truck. How would you protect the optical assemblies at the working end of your cable, which cannot be shielded and are thus exposed to hundreds of Sv/hr? Do you know how Toshiba designed the optics on their Scorpion robot? How would you improve on their materials or lens arrangements? Have you considered the thermal effects of this much radiation, which is capable of heating the internal elements of your assembly to hundreds of degrees?
Read the links I gave, maybe do a bit of googling, and be assured that you have not actually outsmarted hundreds of nuclear physicists and robot experts with your super clever idea.
And glass and probably types of plastics can be quite hardened against negative effects of radiation. Think of transparent windows where you can look at the reactor core of research reactors, NASA space missions with high precision optics that last for decades, etc.
The issue in Japan is their culture, their problem with "loss of face" which inevitably caused problems in the hours when the worst case scenario unleashed - and the whole world watched 24h live while they did little and USA proposed (and had them ready on the nearby ship) to send in helicopters with backup generators but Japan made no official request for help - lesson learned, in the end US should have crossed their border and fixed the generators because Japan hasn't acted rational at all. Even the years later, they could have learned from Russia how to fix it quickly by sending in human people. But again false bride, and "loss of face" gets in their way. They keep going on with business as usual, and the leaks aren't fixed or anything worth mentioning. Chinese and Japanese have a related culture, yet Chinese know what they are doing and are very successful.
"All optical fibers undergo some darkening depending on a number of factors that include: ionization type, optical fiber core glass composition, operating wavelength, dose rate, total accumulated dose, temperature and power propagating through the core. Since attenuation is composition dependent, it is observed that fibers having pure silica cores and fluorine down doped claddings are amongst the most radiation hard fibers. To minimize damage consequences, it is better to use a pure silica core fiber at higher operating wavelength, higher temperature (accelerated recovery) and higher signal power (photo-bleaching)." -- https://en.wikipedia.org/wiki/Radiation_effects_on_optical_f... -- (shortened snip)
Have you ever actually seen an endoscope? Do you have any idea how complicated they are, how many optical elements they have and how precise the tolerances must be?
Did your study of wikipedia reveal the extent of transmission loss in rad-hard optical materials after exposure to levels of radiation near those at Fukushima? Because the link I gave you does. Read that and tell me how long you expect your fiber optics to last down there. I'll give you a hint: not very long.
Tell you what, just make a sketch of your "low-tech" endoscope that withstands hundreds of Sv/hr, deals with hundreds of degrees of internal heating, is waterproof of course, and is robust to extreme physical abuse. And then come up with a way to remotely maneuver it into place through hundreds of meters of industrial wreckage, without using a robot.
Then get ready to be famous, for your brilliant low-tech solution will be lauded by the international team of scientists and engineers working on Fukushima who simply hadn't thought of it for over 6 years.
Why? It seems relatively safe, and there doesn't seem to be much else to do with it.
https://www.google.com/amp/s/amp.theguardian.com/environment...
They are putting a little over 50mL of a weakly radioactive, fast decaying isotope into the ocean. It will be undetectable within a few years.
Natural tritium production (from cosmic rays) occurs at at a rate 3 orders of magnitude higher [0] than is occurring at Fukushima [1].
The robots will likely at least be useful for retrieving the samples.
Why does that surprise you?