There is on-going fission occurring at the site

About the measurement of Xenon at reactor 2, Tepco downplayed it with their word game.

According to their explanation, it was a temporary spontaneous fission, which can be observed even at a stopped reactor, and it was not from Uranium, but from Curium.

If Tepco says so, maybe it wasn’t.

Today Dr.C.Busby sent me his analysis.

The activity ratio of 0.85 reported by TEPCO can only result from an enriched Uranium fission having occurred about 50 hours before the samples were measured or an explosive criticality which occurred 60 hours before the measurements. What these results confirm is that there is on-going fission occurring at the site. The identification of prompt criticality is straightforward in samples obtained or measured within a few hours of the event.



Tepco says it was because of Curium, not Uranium. What do you think ?


I am not an expert on this, so I may have missed something. But as I see it, it is not the quantity of Xenon but the ratios that tell us what is happening. The quantity depends on various factors, how local and extensive was the fission, dilution of the Xenon, how long after the fission, where they measured it etc. The equations suggests that it was measured 50 hours after the fission t = 0. By that time, the Xenons will have changed in concentration from

Xe 133 from 0.01 to 10 an increase of 1000-fold
Xe135 from 9 to 9 for an initial activity of 1×10 to the 15th Bq (100,000,000,000,000 Bq). Hence the change in activity ratios.

The main problem is the critical mass for Curium isotopes. These are, according to Wikepedia,

Cm-242 25kg
Cm-243 10kg
Cm-245 11kg
Cm-247 10kg

It is hard to see how enough Cm managed to get together in the reactor when the production of Cm is very low, and according to my books the production of Cm-243 for example, the hottest nuclide will not be sufficient to produce more than a few grams dispersed thoughout the whole of the reactor fuel. So that sounds like bullshit. Remember, to have a spontaneous fission you need lots of neutrons and something to fission. It could just as easily be Plutonium and probably is, but they wont want to mention the P word. Incidentally Curium decays into Plutonium. The concentration of Pu in a reactor is greater than teh concentration of Cm according to my book.

But of course, in a way who cares. Fission is fission and produces fission products. The baseline is these Xenons have a very short half life, Xe-135 a few hours. The Xenons are daughters of the radio Iodines, so they must have measured those also. But they didnt report them. I-131 decays to Xe-131m which decays to Xe-131. What the measurements show is that these things are still being produced more than 6 months after the explosions. Their stuff about Curium is a discourse manipulation.

Finally, the International Monitoring System for the Test Ban Treaty was mandated to establish a worldwide network of detector systems capable of detecting the four radio Xenons. (CTBTS)

So that data are available. Why havent we seen them? They would answer the question of nuclear vs hydrogen. Probably why we havent seen them.

About this site

This website updates the latest news about the Fukushima nuclear plant and also archives the past news from 2011. Because it's always updated and added live, articles, categories and the tags are not necessarily fitted in the latest format.
I am the writer of this website. About page remains in 2014. This is because my memory about 311 was clearer than now, 2023, and I think it can have a historical value. Now I'm living in Romania with 3 cats as an independent data scientist.
Actually, nothing has progressed in the plant since 2011. We still don't even know what is going on inside. They must keep cooling the crippled reactors by water, but additionally groundwater keeps flowing into the reactor buildings from the broken parts. This is why highly contaminated water is always produced more than it can circulate. Tepco is planning to officially discharge this water to the Pacific but Tritium is still remaining in it. They dilute this with seawater so that it is legally safe, but scientifically the same amount of radioactive tritium is contained. They say it is safe to discharge, but none of them have drunk it.


November 2011