Wednesday, June 4, 2014

#Fukushima I NPP: Construction of Frozen Soil Wall Around the Reactor Buildings and Turbine Buildings Has Started


Following the grudging approval from Nuclear Regulation Authority, the construction of the frozen soil impermeable wall around the reactor buildings and turbine buildings has promptly started.

The first place that the contractor (Kajima) started to drill holes in was the northwest corner of the wall right near the Reactor 1 building.

The frozen soil wall plan by Kajima has been criticized by the media and net citizens as "untested" and "costly". I don't personally share much of that sentiment after looking at the presentation by Kajima and those by two competitors (see my post from May 30, 2013), but I do worry, as the modus operandi of TEPCO is to cut cost by any means. I have a nagging feeling that TEPCO will manage to sabotage Kajima's work somehow.

From TEPCO's photos and videos library (6/2/2014):


An aerial photo by Yomiuri (how they got away with taking a picture is a mystery to me, given the warming from the government/TEPCO on the physical protection) shows how close the wall would be to the reactor building (Reactor 1, in this case). The drilling location is marked with a red circle:


The exhaust stack you see on the right has a spot where the dosimeter went overscale at 10,000 millisieverts/hr (or 10 Sieverts/hr) back in August 2011. TEPCO did calculate how high the radiation might be in November 2013, and it was at least 25 Sieverts/hr on the surface of the pipe. Ambient radiation levels near the pipe range from 19 to 95 millisieverts/hr.

TEPCO's survey map on March 23, 2011 made public for the first time outside TEPCO shows the area with the radiation levels between 6 to 130 millisieverts/hr:


After painstaking removal of highly radioactive debris that littered the location by human workers and remote-controlled heavy equipment, the radiation levels as of May 14, 2014 are mostly between 0.2 to 0.8 millisieverts/hr. The level near the drilling location looks to be 0.35 millisievert/hr:


Still, 0.35 millisieverts/hr is 350 microsieverts/hr; it is nowhere near the level for workers to work without concern for radiation exposure. Three-hour work on that location, and you may exceed 1 millisievert per year excess radiation exposure.

In Fukushima City today (6/5/2014), the radiation levels are mostly below 0.25 microsievert/hr, according to Fukushima Prefecture radioactivity measurement map:


In Tokyo today, a monitoring post in Shinjuku shows the level at 0.0343 microgrey/hr, according to Tokyo Metropolitan Institute of Public Health. It is back to the level before the nuclear accident. At 1 meter off the ground, the radiation level is 0.06 microgrey/hr:

18 comments:

Nick Thabit said...

There's concern that the groundwater inside the wall will rise to surface level, weakening support under already damaged buildings. Also: what's to stop 'excess' mountain groundwater from flowing over the top of this wall?

netudiant said...

Segregating the mess that is Fukushima from the rest of the world, especially the Pacific Ocean, seems to me a worthy goal. The ice wall is a big step in that direction..
It is not a panacea, it does not reach down to bedrock, there may be ongoing large flows beneath the site, but it is a start.
Meanwhile, Japan Inc gets a half decade to develop more effective ways to deal with this cancer on the landscape. That should be long enough to get ALPS working properly and eliminate the need for the ice dam.

Joffan said...

@Nick - making up stupid stories about water doing physically impossible things is not a "concern" - it's simply lying. Water inside the barrier can be pumped down to leave dry basements, finally, and water outside will drain around the barrier to the ocean.

Anonymous said...

@ joffan

Such optimism is laudable... But rather foolish given the historic ineptitude and lies of Tepco (et al) inc.

Anonymous said...

The lies flow thick and fast on both sides. What of the ineptitude of the many pundits who claimed unit 4 was on the verge of collapse?

Anonymous said...

Lmfao 12:48
SPF 4 IS on the verge of collar by any sane engineering standards. The fact that is hasn't (thankfully) does not mean that it won't.

The sane amongst us just hope that the bumbling inept Tepco will manage to empty SPF 4 before another earthquake brings t down.

But how about that Vent stack between R1 & R2 showing 25 SIEVERTS/hr at head hieight. You seen the pics of the broken and rusted support struts? If that comes crashing down, all bets are off as to how any work will possibly continue at all!

And the billions of Bq/litre of strontium90 in the thousands of tons of water within the basements of the reactors and turbine halls- any thoughts as to what's gonna happen to them?

The fat lady has not sung. It ain't over 'til it's over. Claiming all the dire predictions are wrong just because SPF 4 has not collapsed...YET, is just plain asinine.

nyarlathotep almighty said...

frozen wall ? i fear it will requiere too much energy to maintain at correct temperature and the design is bound to fail anyway. frozen wall or not if hot water or corrium bits go that way they'll melt their way through it.

and about shinjuku monitoring posts..
it has been reported before that the governement monitoring posts in fukushima are lying.
why believe those in shinjuku? better ask the citizen to take the measure themselves. the japanese governement lack credibility.

Anonymous said...

Areva-kun,

another lousy post?? The quality of this blog is sinking fast.

To hear that the air 24 meter above the ground is back to the radioactivity levels antecedent to Fukushima is good but not enough, because we do not live at 24 meter height.

How about radioactivity close to the ground, where my 5 years old lives? how does it compare with pre-Fukushima levels? 0.06 microgrey/hr would be +50%, or am I missing something?

Anonymous said...

"I do worry, as the modus operandi of TEPCO is to cut cost by any means. I have a nagging feeling that TEPCO will manage to sabotage Kajima's work somehow"

No need to worry: Tepco is already saving its pennies and spending our health: the frozen wall solution has been chosen because it is *cheaper* than a regular wall.

By the way, a few months after the disaster "some pundits" suggested that Tepco build an underground wall as soon as possible to contain radioactive leaks. Now Areva-kun tells us that Tepco "has promptly started" the construction of its ice-cubes wall... more than three years after the accident. By the way, these leaks are hardly a surprise since Chernobyl had the same problem.

Anonymous said...

Maybe it's a form of bravado seen as necessary by some in that area .. , but to be claiming in an area where a meltdown plume deposited freely and would only feel safe with a detector in hand that levels are back to normal does suggest a promotion of bravado.

Anonymous said...

Anon at 8:44AM, are you dumb and cannot read? The post does say what the level is closer to the ground (0.06microgray). In case you don't bother to know, THERE WAS NO MEASUREMENT at that height in Tokyo (for that matter, just about anywhere in Japan) before the Fuku accident. Take your lousy ass somewhere else.

arevamirpal::laprimavera said...

Anon at 8:44AM, you made my day.

Anonymous said...

Areva - your posts are great, it is the comments section that has become comical.

Anon @ 8:44 - you can calculate for yourself the annual impact of staying in spot where the radiation is 0.06 microgreys an hour. I'll give you a hint, your child has a greater chance of being injured by Santa's reindeer than he/she has of being in any danger from 0.06 microgreys an hour.

Even if the measurement were twice that, your child would be fine. Its not a popular sentiment on this board, where people call you an idiot for not believing the worst about Fukushima, but, the feeling of liberation one has from not cowering in fear from the bogey man in the closet is not to be underestimated.

Anonymous said...

" .. but, the feeling of liberation one has from not cowering in fear from the bogey man in the closet is not to be underestimated."

Really?
Could you elaborate on that experience, I have grown intrigued by your "technique"?

So you are the type where the "bogey man, closeted" is to be directly confronted? with the rapier-wit, presumably?

jim said...

That is so cute, I would of never thought of that. I am definitely making me one or maybe a few! Lol

Anonymous said...

@12:49 As far as I know radiation in Tokyo before the Fukushima disaster was about 0.04 uSv/h. It seems reasonable to think that the additional 50% up to 0.06 uSv/h is caused by the fallout from the accident.

Claiming that there was no radioactivity measurement close to the ground before Fukushima is so obviously ridiculous that does not deserve refutation.

By the way, if I recall correctly, the monitoring post in Shinjuku was located lower that 23 meters before Fukushima; about 15m, if my recollection is accurate.

arevamirpal::laprimavera said...

Anon above, there was indeed no radioactivity measurement close to the ground in Tokyo before Fukushima accident. The metropolitan government started measuring 1 meter off the ground sometime after the accident, not immediately.

As far as I know, the monitoring post in Shinjuku has always been on top of the building that houses the Institute of Public Health.

Anonymous said...

But isn't there a difference now? The radiation is in the dust, right? So it can blow around and people can inhale it. Isn't that different from before 3-11?

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