Thursday, March 8, 2012

3.43 Million Bq/Kg of Radioactive Cesium in "Black Dust" in Minami Soma City, Fukushima

Whatever this substance is, the number is extremely high.

About this "black dust" in Minami Soma, see my past posts, here, here, here.

Minami Soma City's Assemblyman Ooyama reports on his blog (3/8/2012):

試料:ID:080 鹿島区ジサ原C
Cs-134 1,498,000 ± 1,586 Bq/kg
Cs-137 1,932,900 ± 2,481 Bq/kg
TOTAL 3,430,900± 2,945 Bq/kg

It seems to be part of the report by Professor Tomoya Yamauchi of Kobe University who did the measurement. Mr. Ooyama lists the result of 11 samples tested by Professor Yamauchi.

The NGO in Minami Soma, HCR, seems to have some kind of a fallout with the assemblyman's volunteer group over the "black dust", and they've been making rather wild announcements (telling residents that the black dust was plutonium, when there was no alpha emission was detected, for example). I am still trying to get the overall picture on this matter.


Anonymous said...

Not to worry its only cesium. As has been pointed out a number of times it doesn't lodge in the body. No problem. Anyway if you have a problem with this free gift from Tepco it is the responsibility of each and every citizen living in that area to deal with it. If you are worried about the possible effects breathing this dust in could have get a mask, a protective suit and don't forget to wear goggles or alternatively move away but remember it is the responsibility if each individual to deal with it. Don't worry about your neighbors. If they want to carry on as if nothing has happened then leave them to it. It is not your responsibility to care about others.

Anonymous said...

They tested radioactive cesium only, but that doesn't mean there are no other nuclides.

But "As has been pointed out a number of times it doesn't lodge in the body"??

Oh I see, you are Brackett.

Anonymous said...

Brackett! Really! LOL.

Oh and I forgot to end with- Don't forget to smile.

Anonymous said...

@3:34, methinks 3:14 wrote that using high sarcasm. It gave me a good laugh.

Atomfritz said...

Glad that this substance has been officially tested and confirmed to really be a radioactive hazard.
So it's definitely no baseless rumor, but a serious real problem that needs to tackled with.

Regarding this "HCR NGO", my impression is that it actually does much damage to the nuclear-critic movement.
They constantly spread sensationalist rumors that cannot be verified.
A few days ago they reported of highly radioactive blue tap water in Minamisoma glowing in the dark like Cerenkov radiation.
No photos, no measurement readings, no proof at all.
But Fukushima-Diary and Enenews picked up the story and most commenters there seem to have believed that prank.
Such cannot help to curb the constant official rhetoric of "baseless rumors".

Anonymous said...

Both the Diary and ENENEWS tend to publish first and think later.

However, concerning the black dust not emitting alpha radiation, or being plutonium, when it was first discovered the thing that stood out was the fact that it was an alpha emitter much more than beta and gamma. The original readings for the black dust as shown in the links EX-SKF provides are;

Gamma radiation: 10.83 microsieverts/hour

Beta and Gamma radiation: 14 microsieverts/hour

Alpha, beta and gamma radiation: 41.72 microsieverts/hour which leaves alpha radiation at 26.89 uSv/hr

Now all of a sudden theres no alpha emissions. Hmmmmm?

Anonymous said...

Other recent readings from January and February 2012 also showed high alpha readings for the mysterious black dust.

On Jan 27 using an inspector a poster found 3,050 cpm alpha activity by testing with and without an alpha block

On Feb 9th, again using paper as an alpha block, a poster found 7,230 CPM alpha.

What this black substance is, and what it is contaminated with, is still a mystery. To have wildly different readings and compositions of nuclides suggests that the black dust has multiple origins. If it is lava rock used for winter traction on roads, coming from different quarries or location sites might explain this.

Never accept one reading as a tell all. Mr. Ooyama did not sample the same black dust that the original poster sampled.

Post a Comment