Thread by @CherylRofer

@BVasylchenko Definitely a fission event.

I want to look at the isotopes more closely before I say more.

Since folks are picking this up, yes I have looked at the isotopes and feel that there's not much more to be concluded from them.

Sr-91, Ba-139, Ba-140, and La-140 are all decay products of krypton and xenon fission products. 1/

Krypton and xenon are noble gases. They can travel on the wind if the explosion was in the air, or emerge from the water. 2/

I spent some time today discussing with @ferencdv whether we could distinguish what kind of fission event from the isotopes. We agreed that was not possible. 3/

@ferencdv In particular, we were looking at what kind of reactor might have caused this, a fast reactor or a thermal reactor. Some of the speculation is that a fast, sodium-cooled reactor was being tested. 4/

@ferencdv "Fast" and "thermal" refer to the speed of the neutrons in the reactor. That results from the way the reactor is built. Liquid sodium coolant (at several hundred degrees C or more) would create an explosion on contact with water. 5/

@ferencdv But there are other ways a reactor can explode. For this Rover reactor, back in 1965, the control mechanism was rapidly removed.

@ferencdv To go back to the krypton and xenon, a thermal reactor would produce them too. In order to distinguish from a fast reactor, you'd need concentrations from close to the reactor. And their production depends on many factors. So we can't tell between fast and thermal from this info.

@ferencdv All we know from today's release of information is that it was some kind of reactor, probably not the "isotopic power source" that Russia has claimed. 8/8

@ferencdv Supplement: Someone gave me this Meduza article while I was writing the thread. I've lost track, but thanks! It's a pretty good article. 1/
meduza.io/en/feature/201…

@ferencdv The article does not say that the Russian government has admitted that it was a reactor that exploded. But the government meterological service released the isotope data that I've been talking about. 2/

@ferencdv I disagree with the conclusion that the body of the reactor was not destroyed. I think we don't know what condition the reactor is in. It could have sunk right after, or as, it exploded. Will be looking for reports of overhead photos showing salvage ships. 3/

@ferencdv Otherwise, I mostly agree with the article. Might ask why the Russian government allows the meterological service to publish these data but pulled the plug on the IMS stations. 4/4