Wednesday, April 18, 2012

Photos of Reactor 2 Torus Room at #Fukushima I Nuke Plant, Highest Radiation 120 Millisieverts/Hr

The robot "Survey Runner" went down to the Reactor 2 Torus Room on April 18, and TEPCO released two photos of two manholes.

From the TEPCO's survey plan, the robot was to cover slightly over 1/3 of the Torus Room, but in the press conference TEPCO's Matsumoto said about 90% of the Room was covered.

Things look almost clean after seeing the mess in other reactors' upper floors. The robot must have taken more photos and probably videos, but for now TEPCO is willing to release only these photos.

From TEPCO's Photos for Press, 4/18/2012:

North S/C [suppression chamber] manhole:

Southeast S/C manhole:

Note the air radiation levels display at the bottom of the photos. At the north manhole, it is 47.4 millisieverts/hour, and at the southeast manhole 61.4 millisieverts/hour. The numbers next to the per-hour radiation level may be the cumulative radiation level sustained by the robot.

In about 30 minutes between when the robot was at the southeast manhole and when it was at the north manhole, the cumulative radiation (if that's what it is) went up from 57 millisieverts to 82.2 millisieverts.

From TEPCO's press conference on April 18,

  • The robot was in the Torus Room for 3 hours, from 10:52AM to 1:51PM.

  • 6 TEPCO workers accompanied the robot, receiving 0.28 millisievert radiation.

  • The robot got 186 millisieverts cumulative radiation in the 3-hour work.

  • 120 millisieverts/hour in the northwest corner.

  • 90% of the Torus Room covered.

  • No discernible leak, damage observed. Clean.

  • Video, audio recorded by the robot, will be released on April 19.


Anonymous said...

Wonder how they explain..COLD SHUTDOWN..with THAT LEVEL of radiation. Its a totally new use for that term. Kind of thought CS would radiation discovered and the reactors being offline/shutdown/not creating radiation products..

OH..wait..there is no radiation seen..if you do not have a dosimeter--its invisable..So guess they expect as long as nobody CHECKS for radiation levels..Fukushima reactors are in cold shutdown...

Anonymous said...

Are those wooden planks?

Anonymous said...

Think it's a mesh, look at second floor landing in second picture

elbows said...

Yeah its a metal walkway that is suspended above the torus.

As for the term cold shutdown, it has no business being used at Fukushima (except reactors 5 & 6). Not that they ever pretended the radiation levels are low, they are just using this term to mean that the temperature is below 100 degrees C. Its PR of the worst and most potentially counter-productive sort, but sadly Japan appears to be a world leader at this kind of thing.

Anonymous said...

It would be helpful to know the level of radiation-hardening on the Survey Runner.

Anonymous said...

This from NHK, "TEPCO says no water leaks found at No.2 reactor", 4, 18, 21012.

"TEPCO said the robot found no water leaks or traces in manholes on the north and southeast sides of the chamber, where leakage had been suspected.

But TEPCO has not confirmed whether the robot was able to capture images of pipes connecting the suppression chamber and a containment vessel where the company also suspects water leakage."

Photos of piping - great idea when looking for leaks.

ToB said...

I know this isn't relevant, but these shots make me think of the well in Ringu.

Anonymous said...

Just to be clear - this is reactor 2 where "radiation inside the containment vessel has reached a lethal 73 sieverts per hour and any attempt to send robots in to accurately gauge the situation will require them to have greater resistance than currently available. Exposure to 73 sieverts for a minute would cause nausea and seven minutes would cause death within a month, Tokyo Electric Power Co. said. The experts said the high radiation level is due to the shallow level of coolant water — 60 cm — in the containment vessel, which Tepco said in January was believed to be 4 meters deep". All according to Japan Times on March 29, 2012.

None of that has changed right?

arevamirpal::laprimavera said...

@anon at 12:04AM, no nothing has changed. 73 Sievert/hour is the radiation inside the Dry Well portion of the containment. The robot ran on top of the torus.

Anonymous said...

That`s bad idea to opent that hatches.
Torus is a main plase where RA dust & evaporized RA elements rests (except for "elefant foots" at the reactor`s bottom). Levels 4-8 Rh/hour is "almost clean" in that circumstances. Open this hatch will rise levels to hundreds (if not a thousands) Rh/hour.
Second. Thorus is a reactor`s 'drain'. Probably it is filled with extremely radioactive water.
The only way is to make a pinhole and watch/measure inside.

Anonymous said...

82.2 millisieverts is a flash of torus content thru torus wall. Level inside can be calculated.
73 sieverts is level inside drywell where melted fuel probably rests as chernobyl`s "elephant foot"
Anyway is bad idea to go there for the next 100 years.

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