Finally Some Science on the Japanese Reactors!

Got this link from a friend today on FB. Refreshing to actually hear some logical fact-based analysis of the situation from real authorities on the subject! It even has pictures for all of us 'big-word challenged' folks!

MIT NSE Nuclear Information Hub

Explosion at Unit 2
Posted on March 15, 2011 by mitnse

It was reported earlier today that the explosion at Unit 2 of the Fukushima Daiichi plant damaged the suppression chamber. As discussed in the previous post, the suppression chamber/torus (i.e. donut shape vessel containing water) is used to depressurize the reactor. The suppression pool is designed to condense the hot steam from the reactor, but can only do so as long as sufficient cold water remains in it. It should also be noted that the suppression pool is part of the primary containment.
Hydrogen gas from the cladding oxidation with steam collected in the suppression pool and ignited. This scenario differs from those of units 1 and 3 where the explosion occurred outside the primary containment in the upper part of the reactor building. The reasons why the steam/gas mixture was not released to the reactor building are still not clear. This breach of primary containment is certainly more serious than the situation in units 1 and 3. Seawater is still being pumped in the containment and the reactor vessel. At this time radioactive releases from unit 2 have been similar to the ones seen from units 1 and 3.

Just like the last guy from mit saying things could not get to where they are today.

the blind leading the blind into a ditch.

Here's a better site: www.world-nuclear-news.org...

World Nuclear News

The section on Regulation & Safety is where all the stories are on the failed reactors.

www.world-nuclear-news.org...

This story (www.world-nuclear-news.org...) mentions the radiation detected vs. announced by the Japanese Government:

Radiation levels on the edge of the plant compound briefly spiked at 8217 microsieverts per hour but later fell to about a third that.
...
Japanese authorities told the International Atomic Energy Agency (IAEA) that radiation levels at the plant site between units 3 and 4 reached a peak of some 400 millisieverts per hour. "This is a high dose-level value," said the body, "but it is a local value at a single location and at a certain point in time."

Later readings were 11.9 millisieverts per hour, followed six hours later by 0.6 millisieverts, which the IAEA said "indicate the level of radioactivity has been decreasing."

Just a note, 400 millisieverts (mSv) is quite a bit. A CT scan is 10 mSv. The former estimate of 8217 μSv = 8.217 mSv, just under a CT scan. However a CT scan is brief.

Radiation at Fukushima Daiichi - 400 mSv
CT Scan - 10 mSv
1year natural radiation dose - 1 mSv
Chest X-Ray - 0.05 mSv
Travel on airplane - 0.04 mSv
24hr natural radiation dose - 0.01 mSv

Originally posted by Kargun
Just like the last guy from mit saying things could not get to where they are today.

the blind leading the blind into a ditch.

Actually if you read the page, it's an analysis of what has happened from a technical perspective of folks who know exactly how the reactors are designed. The article even states

"...This breach of primary containment is certainly more serious than the situation in units 1 and 3. Seawater is still being pumped in the containment and the reactor vessel. At this time radioactive releases from unit 2 have been similar to the ones seen from units 1 and 3..."

To me, it is simply a fact-based assessment without the speculation or hyperbole.

reply to post by dbriefed


Good link, thanks for mentioning it. The articles are short, but do cover a wider scope than the MIT site. I do still like the MIT site for the detail provided though. Bookmarked it for my multiple-daily updates!