Record radiation level detected inside damaged Fukushima reactor

Japantoday ^ | Feb. 3, 2017 | NA

[Reily]

If a 6 core Intel I7 has something like 1.1 billion discrete elements i.e., transistors. 1 transitor = 1 tube (or valve).

Built from tubes the robot would likely be as big as a small moon & generate the heat of a blast furnace.

[chimera]

Here is a link to the technical report for this study, if you want something other than from the popular media (which tends to be a bit embellished).

http://www.tepco.co.jp/en/nu/fukushima-np/handouts/2017/images/handouts_170130_02-e.pdf

[Noob1999]

Actually, the problem started when the designers of the plant decided to place the emergency generators to power a shutdown scenerio at a location near sea level.

If they had been smart, the gensets would have been sited on the bluff above the plant, and emergency power would have kicked in within seconds, to shut down the plant. Once the gensets we’re flooded, it was all over!

Exact thing that caused Katrina floods to overcome the emergency pumps.

[zek157]

Liquid Flouride nuclear reactors are basically fail safe and do not produce waste. The technology has been around since the 50s but was abandoned because it doesn’t produce nuclear materials that were needed to support nuclear weapons programs at the time.

Big difference. Nuclear can be extremely safe.

[steve86]

And the components no doubt are already hardened/shielded to the maximum extent practical. It would be feasible to implement the robot mechanical functions using hydraulics, but the sensors and cameras are another matter. That unprecedented level of radiation (within the scope of man’s activities) is going to do funky things to a broad range of materials: solid, liquid, and gaseous.

[PAR35]

Run it on punch tape instead of electronic memory. Mechanical switches. Young pups need to learn some history.

[Reily]

Radiation shielding is capture cross section & shielding thickness. I am sure as you pointed out the robot is probably already at edge of what can be done to protect it.

[Reily]

and the post data analysis done on Walther WSR160s.

[Redcitizen]

Same here. It was REM till I woke up.....

... :D

[fruser1]

Enough there for an explosion?

[PAR35]

What? Your slide rule is broken?

[Vinnie]

If they had been smart, the gensets would have been sited on the bluff above the plant,

IMO nuke plants should be built below their cooling water source. If pumps fail, manually open the valves and let gravity do the rest.

Yes, it would restrict where the plants were built but better be safe than sorry.

[Reily]

My freshman physics class was the last class to be taught slide rule. I still have it somewhere.

[gundog]

Some locals were running around Charleston, OR with a Geiger counter and some of Alex Jones’ people and got shut right down.

[gundog]

Some locals were running around Charleston, OR with a Geiger counter and some of Alex Jones’ people and got shut right down.

[shotgun]

The spent pool is located above the reactor vessel. During refueling, they open the vessel and remove the spent bundle. This is all done underwater so the spent rods, which are highly radioactive, are never exposed to the atmosphere. Once adequately “cooled” they are transferred out of the pool into large casks and moved to a new location.

Here in the US those rods that are in the casks were to be transferred to Yucca Mountain for permanent storage but that contract has been broken by Obama and Harry Reid. Of course Harry didn’t have any problem with spending billions on Yucca until the time came to open it up for it’s intended use.

[Nuc 1.1]

The fault line, near the ocean build, and design assumptions regarding the potential for tidal waves are legitimate concerns. The pool on the refueling floor is called a spent fuel pool. Used fuel from refueling is stored there. The initial design was to store the fuel for about five years then reprocess it. Except for refueling spent fuel pool water does not communicate with the reactor. Spent fuel pool water is not used to make steam to make electricity. The location simplifies refueling. The pool is fully seismic and is designed so that it cannot drain below the level of required shielding above the spent fuel. IMHO they may have been able to save the reactors equipped with RCIC turbines by thinking way outside of the box. It would have been risky and would have required cutting the RCIC turbine exhaust line and routing the exhaust out of the reactor building. Do-able but dangerous. All BWR RCIC turbine exhaust lines should have the ability to exhaust to the atmosphere added to their normal exhaust path.

[Tilted Irish Kilt]

shotgun :".. the casks were to be transferred to Yucca Mountain for permanent storage but that contract has been broken by Obama and Harry Reid.
Of course Harry didn’t have any problem with spending billions on Yucca until the time came to open it up for it’s intended use."

TIK: That is because it brought jobs and industry to the area, in preparation work.

shotgun :" Once adequately “cooled” they are transferred out of the pool into large casks and moved to a new location."

TIK: The problem is that with Yucca Mountain closed, there is no place to transport the spent rods to another location.
Many of those spent rods (fuel) are being warehoused elsewhere on the site of the nuclear plant until other storage arrangements can be made.
Those spent rods still need to remain secured and under guard (security expense).

[Jim W N]

I’m not convinced - yet.

Once nuclear power plants are actually safe then it seems like things like Fukushima shouldn’t happen.

[AFPhys]

I can envision a (rather large) cable controlled robot that could withstand this radiation flux for hours. However, I do not know of any camera, tube or Solid State technology, that would be worth a darn after a few minutes in that flux.