Friday, December 16, 2011

Former Japanese PM Hatoyama: #Fukushima Reactor 3 Nuclear Explosion Likely

It turns out that former Prime Minister Yukio Hatoyama had more than just the recriticality back in March and April to talk about in his Nature article that was published on December 15, a rather awkward day it must have been for the Noda administration who was going to declare the end of the Fuku I Nuke Plant accident.

Even though the original English version of the Nature article is only available to the subscribers, Nature Asia has the full translation made available to anyone.

In the article, he and his co-writer Tomoyuki Taira talks about the possibilities of recriticality (chlorine-38 detection), nuclear explosion of Reactor 3, and melt-through of the corium contaminating the groundwater.

No wonder Yomiuri Shinbun, when writing about Hatoyama's article in Nature magazine, decided to only mention TEPCO nationalization and recriticality in March/April - a subject safe enough to talk about now.

In concluding that it may have been a nuclear explosion at Reactor 3, Hatoyama forgoes the mechanism of how a nuclear explosion could have happened and focuses on the evidence of transuranic elements scattered far outside the plant, saying a hydrogen explosion wouldn't be powerful enough.

The original was English, and the translation (by Nature Asia?) was edited by Mr. Taira, according to Nature Asia website. The following is my quick translation back into English from the Japanese translation of the portion about Reactor 3 nuclear explosion. As such, it will be probably nowhere near the original English in terms of expression.

From "Nuclear energy: Nationalize the Fukushima Daiichi atomic plant" by Tomoyuki Taira & Yukio Hatoyama (translation into English from the Japanese translation of the original English):


Possibility of Nuclear Explosion


We need to answer the question of what caused the series of explosions at Fukushima I Nuclear Power Plant. Initially, they were reported as hydrogen explosions, i.e. explosions as the result of chemical reaction at a high temperature between the alloy in the cladding and the water vapor in the reactor core. However, this is not conclusive. Other possibilities exist, and they are nuclear explosions and gas explosions other than hydrogen gas.


How much, and what kind of radioactive materials were dispersed by the explosions, and how far did they spread? What is the condition of spent nuclear fuel stored in the Spent Fuel Pool of Reactor 3? To answer these questions, it is imperative that we know one way or the other if a nuclear explosion took place. From two observed facts, we believe a nuclear explosion is more likely. First, several transuranic elements have been detected several tens of kilometers away from the plant. Second, the steel trusses in the upper part of the reactor building of Reactor 3 are twisted as if they had been melted.


According to the reports by the Ministry of Education and Science, curium-242 (242Cm) has been detected at a location 3 kilometers from the plant, and plutonium-238 (238Pu) has been detected at a location 45 kilometers from the plant. These are extremely toxic, and if ingested they will cause internal radiation. 242Cm's half life is short (about 163 days), and the deposition of 238Pu around the plant is far greater than normal, leading the Ministry of Education and Science to conclude these are not the radioactive fallout from the past atmospheric nuclear testing but that they were emitted from Fukushima I Nuclear Power Plant. If that's the case, pieces of broken spent nuclear fuel rods may have been scattered around the plant, and it is extremely dangerous.


These transuranic elements are not carried by the radioactive plume like much lighter cesium or iodine. Therefore, they must have been blown out by an extremely large force. It is not known to us whether a hydrogen explosion is powerful enough to disperse transuranic elements this far. It is unlikely that a hydrogen explosion generated a high enough temperature that would melt steel. TEPCO initially announced that there was a white smoke from Reactor 3 explosion. However, the later investigation has revealed that the smoke was black, and a hydrogen explosion is not considered to generate such a black smoke. Our conclusion therefore is that it [explosion of Reactor 3] may have been a nuclear explosion. It is equally important to investigate whether a different explosive gas [other than hydrogen gas] was being generated at that time.

Hatoyama, as a former prime minister and a high-ranking official of the Democratic Party of Japan, has had access to more detailed information about the accident from both the government source and TEPCO, in addition to the data from nuclear experts that he invited to his study group on the Fukushima accident, though he complains in the Nature article how he was frustrated with the slow response from TEPCO. (He is referring to the 99% blacked out operation manual from TEPCO.)


Anonymous said...

Thanks for posting this with translations.

Darth3/11 said...

TEPCO...leading the way straight to hell.

no6ody said...

Seconded! what anon at 1:28 said!

In this post, EX-SKF has a picture of the crater over the spent fuel pool:

Here's a video released in May showing the explosion (about 50 seconds in).

In my opinion, the only large source of energy available for the explosion was the spent fuel or the fuel in the reactor itself, and the crater is over the spent fuel pool.

Anonymous said...

like the others said, thank you
fine work you are doing EX
-enenews admin

Be Well said...

This is the first time I have heard of melted steel in reactor 3. Does anyone have a reference?

Atomfritz said...

Regarding the apparently molten steel beams:
Please keep in mind that the cause is not necessarily explosion heat. It would be difficult to heat steel so quickly. However, if metals are being deformed massively very quickly because of mechanical force, they can get very hot because of the internal friction and soften, even melt. This could also be a reason for the paint being burnt/damaged.

Regarding the chlorine:
the samples were apparently taken on March 24 in the basement water of Unit 1.
They measured 1.6 million becquerels/milliliter, respective 1.6 trillion becquerels/cubic meter.
I do not know how much water this time already run up in the basement, maybe somewhat less than the around 10,000 cubic meters where it stagnates now.

So let's assume 10,000 cubic meters of 1.6 trillion becquerels each.
This would result in about 16,000 trillion becquerel of Cl-38, if dispersed evenly.

I don't know if these 16 E+15 Bq are negligible, even if this resembles "only" somewhat more than three milligrams of of Chlorine-38.

Some other things have also to be considered.
First, the salt water was not circulated, it was only a short one-time passage.
A large part of the salt might have been lodged in the reactor/containment, so that only a part of the radioactive chlorine actually reached the basement water. (Remember, the NRC expressed concerns that the seawater cooling might create new difficulties because of the salt crusts hampering the cooling water flow)
Second, a large part of the radiochlorine that didn't get lodged in salt crusts might have already decayed on the way to the basement.
Third is the question, whether this large quantity of radiochlorine could at all have been created by neutron-emitting decay ("spontaneous fission") of plutonium etc only.

So the actual "production" of radiochlorine could have been much higher than the measurement indicates.
The fact alone that Tepco/govt apparently attempted to cover-up the radiochlorine issue makes me wary that there is something foul been hidden.

DD said...

Thanks, English translation fine. Well done.

We can now see the breakup of the "silence alliance" beginning to happen. Expect more, and expect more late arrivals of the truth wagon, and expect more accusations, counter accusations, and laughably failed attempts at spin.

Well, I for one always went along with the concept of a criticality explosion. But it pains me that others who should have, and clearly must have, known better sat on their consciences and lied brazenly to the rest of the world. Shame on such!

Thanks once again Ex-SKF.

Anonymous said...

"It is unlikely that a hydrogen explosion generated a high enough temperature that would melt steel."

Adiabatic Flame Temperature of Hydrogen in Air: 2,045°C (

Melting Point of Steel: 1,425°C to 1540°C (

Difference between Adiabatic Flame Temperature of Hydrogen in Air and Melting Point of Steel: between 505°C and 620°C.

In short, the explosion, if it were hydrogen only, would have exceeded the melting point of steel by more than 500°C. The only question is whether the steel would have been exposed to this temperature for long enough to melt and that would probably depend on the thickness of the steel.

Atomfritz said...

I find this page ( ) with its illustrations very instructive.

Just keep in mind that to get a such steam explosion hypothesized on this page it would not be necessary for corium falling into water.

In Chernobyl the reactor (or part of it) was doubling its power in intervals of less than one seconds, until it blew up when it was at a peak power of over 100 gigawatts and the water in it evaporated explosively.

As control and absorber rods melt away long before the fuel assemblies, this could have created a configuration like in the Chernobyl reactor power excursion (explosion).

Atomfritz said...

@ anon 11:32

The short duration of the hydrogen explosion heat would not transfer sufficient warmth to even discolor the painting.

Anonymous said...

Following your post on this subject, I looked up the Dec 15 issue of Nature through my employer's subscription. In addition to the article by Hatoyama, the issue contains an editorial with unusually blunt criticism of the Japanese government's modus operandi over the years:

"Many times in Japan's recent history, the government has handed responsibility for dealing with issues involving tricky scientific concepts to bureaucrats or politicians. All too often, these officials, not understanding the issues, do what governments shouldn't do — hide the problem and hope it will go away. In the meantime, politicians fumble for answers, while ill-informed government spokespeople tell confused stories that can make them look foolish, irresponsible or deceitful.

This is how the government handled Minamata disease caused by industrial mercury poisoning in the 1950s and 60s, the HIV-tainted blood products problem in the 1980s, and the BSE scare of a decade ago. And now it is how it has handled Fukushima. Fear of spreading panic, for example, prevented warnings being issued on the dangers of radiation predicted by simulations. As a result, more residents than necessary were exposed."

You may contact me (johnoah [at] gmail [dot] com) if you would like a copy of the full Nature editorial or the original English version of the article by Hatoyama.

Anonymous said...

".. and a hydrogen explosion is not considered to generate such a black smoke. "

That really is an important signature. TEPCO wishing it was white smoke is infantile.

".. if metals are being deformed massively very quickly because of mechanical force, they can get very hot because of the internal friction and soften, "

Hydrogen at any concentration on the planet's surface conditions is not capable of bending steel girders that quickly, those girders are massive.

"The fact alone that Tepco/govt apparently attempted to cover-up the radiochlorine issue makes me wary that there is something foul been hidden. "

Exactly. The fact they went mute on nuclides detected is not a minor one.

"Adiabatic Flame Temperature of Hydrogen in Air:"

Do come on. The hydrogen was escaping confinement with exceptional rapidity.
Heh, have they ever combusted pure hydrogen in anything other than ceramic crucibles, by your version 11:32 AM ?

Atomfritz said...

We have also to consider that Hatoyama in his position has access to classified information that is not available to the public.

So it could perfectly be possible that the molten steel wasn't shown to the public because the danger of causing panic would be too high.
Same for a criticality excursion (euphemism for nuclear explosion) in the melting reactor remains.

There could be many things that the high pigs knew/know of and kept secret for not being the traitor who leaks it first.
But after this kind of "cold shutdown" the current government is obviously the traitor...

I believe we are in for more surprises, anyway.

Atomfritz said...

Hatoyama seems to be right...
(sorry for double-posting, but I think this belongs here)

Be sure to read all the pages the author links to.
The author is a retired reactor engineer, but he is (imho) honest and looks for the truth.

He explains in detail and well-written what probably happened (criticality excursion, explosion with blackened steam/smoke), and _why_ it happened.
He shows in his photo and video analysis what Tepco apparently tried to hide.

Remember, Tepco showed practically no detailed video/pics of reactor 3. Only very short low-res flyovers and photos from big distance and angles that obscure the really interesting parts.

Please read the post and the links the author (jim hardy aka Analog) provides.
He actually proves what Hatoyama said about the nuclear explosion.

Anonymous said...

I just bought online the original article from NATURE in English. You did a fine job translting it! Here is the excerpt about nuclear explosion:
"Another question that must be answered is what caused the explosions at the site. They were initially reported as being caused by the ignition of hydrogen generated by a high-temperature chemical reaction between the alloy covering the fuel rods and the vapour in the core. But, again, this has not been settled. Other possibilities include a nuclear explosion, or the ignition of other gases.
Knowing whether a nuclear explosion took place is essential for predicting how much radioactivity might have been released, what it would have consisted of and how far it would have spread, as well as the state of the spent-fuel rods stored in a pool in unit 3. Two observations suggest that this is plausible. First, some metals heavier than uranium have been detected tens of kilometres from the plant. Second, the steel frame on top of the unit-3 reactor building is twisted, apparently as a result of melting.
“Solutions for the Fukushima nuclear disaster must be based on the worst-case scenario.”
Japan's Ministry of Education, Culture, Sports, Science and Technology (MEXT) reported finding heavy metals such as curium-242 up to 3 kilometres from the reactor site and plutonium-238 up to 45 kilometres away. These isotopes are deadly poisons if ingested, causing internal exposure to radiation. Because 242Cm has a short half-life (about 163 days), and because the concentrations of 238Pu around the plant were much higher than usual, MEXT concluded that these radionuclides were not fallout from past nuclear tests in the atmosphere, so must have come from the Fukushima reactor. If so, they suggest that broken spent-fuel rods might be scattered around the site — a considerable hazard.
Such elements are too heavy to have been borne in a plume, like the lighter caesium and iodine, so they must have been blown out with great force. Whether a hydrogen explosion would have been powerful enough to scatter heavy metals that far remains unclear. And a hydrogen explosion should not have generated enough heat to melt steel. Initially, TEPCO claimed that the explosion in unit 3 generated white smoke; on re-examination, the smoke was black, and therefore unlikely to have been caused by a pure hydrogen explosion. So a nuclear explosion is a possibility. Whether other explosive gases were present on the site would be equally important to establish."
from Janick in Japan

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