A few bothersome facts

I have been consistently non-alarmist on this blog because I myself understand what is going on at Fukushima Daiichi, at least in the big picture. There is one assemblage of fact, however, that surrounds No. 2 plant and seems quite troubling at the moment. I will relate this clearly -- and I invite you to go back in the blog and check the facts.

About 24 hours ago or so we reported right here, from TEPCO and JAIF sources that the water injection to the Number 2 plant was borated. This struck me as odd, since no boron has been added to the water being injected to No. 1 or No. 3 plants. If it was, it wasn't noted but I'd doubt this kind of omission given the thoroughness of the documentation the Japanese are releasing.

We also had at least one report of high radiation fields in the No. 2 plant days ago although we never did get a solid breakdown on what type of radiation this was.. one would have to assume gamma with possibly some neutron.

We now have reports of contaminated water in the turbine building at No. 2 plant that is ten million times the normal activity of primary coolant.

One of the isotopes being found in this water is reportedly Iodine-134. I-134 has a half life of 53 minutes.

If you put this all together you arrive at the fact that uncontained fissions in Uranium fuel are occurring in the plant. (And that the water being used to cool the core right now is getting out.)

If there is a significantly damaged core, and some of this core has melted down into a lump or pile, it's possible that this material (a melted mixture of uranium, and zirconium, and other metals that in the industry is referred to in accident discussions and predictions and calculations as "corium," or all sorts of core metals melted together into a non-homogeneous mixture) may not necessarily be overall and throughout in what you would call a shutdown configuration. Normally the core being fully shut down depends upon the relation of the fuel rods (or plates in some designs) and the fully inserted control rods which absorb neutrons to stop the fission process. When a core melts and fails, the exact orientation of all these materials is lost and if enough fuel material can move away from enough neutron absorbing material in the corium, an increased rate of fissions per unit time in the Uranium fuel could theoretically result. Of course, one major problem is moderating the neutrons -- normally the water in the core 'moderates' or slows down the neutrons to thermal energies. It takes thermal neutrons to trigger fission in the U-235 in the fuel. However, if enough corium metals of other types are melted into the pile it's conceivable that you could have a higher fission rate .. all the while being unable to attain any sort of recriticality since there is no good geometry and not enough moderation.

Is this happening at No. 2 plant? It sure sounds like it; the giveaway to me that at least TEPCO or else NISA suspects that it is or may be is the injection of borated water.

This is speculation based upon the facts already released and mentioned previously here, which I've also delineated in this post. We will surely keep on top of this nagging detail and follow it to see what happens.

5:35 AM Eastern Sunday 3/27
ATOMIC POWER REVIEW

UPDATE: TEPCO seems to be hedging their bet on this.. indicating that there is no credible proof yet of how the material is presently exiting the core. Calculations will have to be done to determine the I-134 inventory in the core at this time, very many days after shutdown. The best I have here at hand is the old TID-14844 at the moment. As noted before we will keep looking at this possibility and hope that it is indeed remote.