
Tepco carries out examination in Fukushima by remote-controlled probe - Ultramanoid
https://www.japantimes.co.jp/news/2019/02/13/national/tepco-completes-physical-examination-probe-melted-reactor-fuel/
======
themodelplumber
How fascinating that they might need to develop new tools for the unique
circumstances. Does anyone know if they would keep the design proprietary and
e.g. mine it for profits, or are they under any requirement for open-design,
open process?

It strikes me that in what can be described as a "disaster" from many angles,
they are potentially modeling a working containment-and-recovery process from
other angles. This could be extremely valuable, the exception to the safety
tradition that writes new rules providing higher leverage in working with
beneficial and yet hazardous materials.

~~~
joe_the_user
It's been quite a few years and this is the first time they've made to
reactor.

My guess is this success is not so much a matter of finally creating a clever
design as it is the radiation has finally gotten down to a manageable level. I
know they tried earlier with quite a variety of robots, all of which were
rendered useless by the radiation levels (sensors and circuits becoming too
unpredictable).

~~~
geomark
What are the radiation levels the failed robots experienced? Searching, I keep
finding information about radiation levels in reference to human health. But
I'm interested in the total dose those robots get before they fail. I used to
work on space electronics that had to survive mega-rad levels of total dose
radiation. How quickly do electronics accumulate those levels inside
Fukushima?

~~~
pvaldes
Maybe I sound naive, but why do we need to move electronics there?.

Why they don't just use a disposable lead tube ending in the minimum working
telescopic lens (mechanical) system possible and a cable moving electrons
inside to build an image in a computer at km of distance. The brain of the
robot should be out of the building, not inside.

Couldn't we estimate radiation by how long some well known matherial is
surviving before to crash instead to use a sensor?.

~~~
pjc50
Ah, the HN "why don't they just"...

A good overview: [https://www.wired.com/story/fukushima-robot-
cleanup/](https://www.wired.com/story/fukushima-robot-cleanup/) containing the
excellent phrase "Until we send the bot in, we don’t know what the conditions
are. And after it’s sent, we can’t change it".

[https://www.independent.co.uk/news/world/robots-fukushima-
nu...](https://www.independent.co.uk/news/world/robots-fukushima-nuclear-
disaster-dying-probe-clean-up-tepco-toshiba-reactor-nuclear-
radiation-a7612396.html) : "The latest attempt to harvest data on Fukushima
failed after a robot designed by Toshiba to withstand high radiation levels
died five times faster than expected.

The robot was supposed to be able to cope with 73 sieverts of radiation, but
the radiation level inside the reactor was recently recorded at 530 sieverts
per hour."

~~~
jandrese
If anybody is curious how much radiation a sievert is, there is a handy chart
for reference:

[https://xkcd.com/radiation/](https://xkcd.com/radiation/)

530 sieverts/hour would mean a person exposed for less than a minute would be
a dead man walking. Even a 30 second exposure would be difficult to recover
from. Electronics would suffer from constant bit flips.

You would really need to keep most or all of the electronics back in a
shielded box at the end of a long cable and make the robot as dumb as
possible. This sadly only goes so far since you do need sensors that are made
out of electronics on the robot. Cameras for example. It's a complicated
system, and worse you need this robot to be quite capable if it's going to
deal with uneven terrain and eventually breaking up and removing the melted
fuel.

~~~
pvaldes
> a person exposed for less than a minute would be a dead man walking.

Yup, fortunately robots aren't alive

We know how to fabricate telezooms to take a photo to an animal at 400m
distance. We use periscopes rutinely that do not need electronic necesarily.
We know how to take a photo to the reflection in a mirror and zoom it later.
We have the technology to make a mirror with a very finely polished metal
surface (would be that sensible to radioactivity?), and we have all the time
in the world to make a big photo secuentially from many small simple photos,
ommatidium like. with less info encoded ...

Why we need electrons when we could use photons and an optic cable to
translate the info at 100 km in some fractions of second? What happens with an
optic cable when radioactivity hits it?

~~~
nate_meurer
Optical materials of all kinds are vulnerable to darkening, clouding, and
embrittlement by much lower levels of ionizing radiation than those in the
reactor [1]. Darkening along the length of an optical fiber adds up quick, and
will quickly render it opaque. Shielding won't help you at these radiation
levels; you would need inches of lead cladding [2], and even then your fiber
optics might not have a useful lifespan, exposed to at least tens of Sv/h
along much of the length. And shielding offers nearly zero protection against
neutron radiation.

Also note that the radiation in the reactor can heat the internal elements of
your perisccope by hundreds of degrees, so without a cooling system your
optical system's tolerances are at risk. Remember to make everything
waterproof, and robust against shock and vibration.

After you figure all that out, you still need to get your periscope into the
reactor somehow. Humans can't go closer than about a kilometer, and any robot
you use must be able to navigate industrial wreckage.

These are not simple problems.

1 -
[http://www.dtic.mil/dtic/tr/fulltext/u2/a013786.pdf](http://www.dtic.mil/dtic/tr/fulltext/u2/a013786.pdf)

2 - [https://www.eichrom.com/wp-content/uploads/2018/01/gamma-
ray...](https://www.eichrom.com/wp-content/uploads/2018/01/gamma-ray-
attenuation-white-paper-by-d.m.-rev-4.pdf)

~~~
pjc50
"Virtually unusable after lengths of as little as 10m", wow. I'd no idea they
were that vulnerable.

------
AaronM
Anyone know why it was raining inside the reactor?

------
trhway
seems that there is more progress on Mars than at Fukushima. That illustrates
the true scale of risks/dangers/difficulty of dealing with nuclear disasters.
Basically we have no technology to deal with nuclear disasters. All we can is
just to wait for the radiation to decrease while for example in Belarus
several thousand people die per year from Chernobyl related cancers (plus
associated birth defects, etc.). And we can do nothing. This is why the only
way we have is like Germany - getting rid of nuclear completely. While nuclear
is our best bet in space, on Moon/Mars/etc., it just cant be used on Earth as
we completely lack necessary technology.

~~~
scatters
That is a lie.

According to the WHO
([https://www.who.int/ionizing_radiation/chernobyl/20110423_FA...](https://www.who.int/ionizing_radiation/chernobyl/20110423_FAQs_Chernobyl.pdf)),
a "large fraction" of 6000 thyroid cancer cases (to 2005), of which 15 were
fatal, are attributable to radiation exposure. No other health impacts are
supported by evidence.

As such, the actual figure for deaths (at present, over 30 years since the
incident) resulting from the Chernobyl incident is somewhere between zero and
one per year.

Even if it was thousands of deaths per year (which it is not), that would
still be far below the number of deaths caused by burning coal.

~~~
trhway
>As such, the actual figure for deaths (at present, over 30 years since the
incident) resulting from the Chernobyl incident is somewhere between zero and
one per year.

and that can't be farther from the Belarus reality. For example
[https://www.ncbi.nlm.nih.gov/pubmed/16506213](https://www.ncbi.nlm.nih.gov/pubmed/16506213)

" In addition, a significant 2-fold increase in risk was observed, during the
period 1997-2001, in the most contaminated districts (average cumulative dose
of 40.0 mSv or more) compared with the least contaminated districts"

Breast cancer in general is the most frequent one - 1 in 8 women will get it
over lifetime. Now double that. That is the reality of life in Gomel and
Mogilev regions which took the brunt of the Chernobyl accident.

Russia and Ukraine have the same cancer rates, while Belarus - same people,
same habits/lifestyle/etc. - have 1.5x cancer rates of Russia/Ukraine
resulting in about 15000/year extra cases and the majority of those extra
cases are in the Gomel and Mogilev regions. The cancer mortality in Belarus is
30%-50%. Do the math.

>According to the WHO
([https://www.who.int/ionizing_radiation/chernobyl/20110423_FA...](https://www.who.int/ionizing_radiation/chernobyl/20110423_FA...)),
a "large fraction" of 6000 thyroid cancer cases (to 2005), of which 15 were
fatal, are attributable to radiation exposure. No other health impacts are
supported by evidence.

that is a lie. The minimally honest WHO report would at least added something
like this:

"There is a significant increase in cancer rates in the most contaminated
districts. WHO sees no evidence connecting it to the contamination.
Correlation is no causation. Pure random distribution. What are the chances!"

