Returning To Busby's Excess Gas

I had a post on Dr. Chris Busby's lies about the excess helium gas formation in spent nuclear fuel canisters earlier this month.  His point is that there will be a buildup of He over time and the canisters won't be able to contain the pressure and will eventually rupture.  I had simply caught him lying about whether the Swedish authorities were aware of the problem or not, and they obviously were, contrary to Busby's claim.

However, I didn't address his main claim at the time because I hadn't read his paper.  He has since put a link to the paper on his YouTube upload.  The paper is atrocious!



His main claim begins with this:

"It is clearly possible, though I have not had the time, to calculate the exact alpha flux with time on the basis of summing the various decays of all the nuclides and their alpha emitting progeny. However I can use a conservative approach by employing the total repository value of 1.4 x 1019 Bq to make some interesting schoolboy calculations. In this I ignore the decays of the parent in the series since as Table 4.1 shows there are a whole series of alpha emitters downstream of the shorter half-life parent alpha-emitter nuclides.
If there are 6000 canisters, the content of one canister by simple division is 2.3 x 1015 Bq of alpha emitters, and since an alpha particle is a charged Helium ion, this means there are the same number of Helium gas atoms being produced every second. In 100,000 years (the kind of time frame we are being invited to consider) this is 7.25 x 1027 atoms. One Mole of an element contains 6 x 1023 atoms and so there will be 12088 Moles of Helium produced in the canister in 100,000 years. Since Gay Lussac’s law tells us that at STP (ambient temperature and pressure) one Mole of a gas occupies 22.4 litres, we can say that the volume V of the Helium in a canister at STP would be 270789 litres i.e without any consideration of heating expansion. Let us turn to the canister. The BWR canister is a cylinder of diameter 100cm and length 483 cm."

Etc., etc.

He is making a very fundamental error regarding alpha particles...they don't pop into existence!  They result from the decay of parent atoms...the particles were originally a mass associated with their parents.  The parent atom already exists within a fuel pellet, which exists within the fuel rod.  Due to their mass and charge, alpha particles don't travel outside the pellets (maybe a few, but shortly stopped) nor the rods.

The alphas will attract electrons to become He atoms with a lower density than the original parent atom.  The buildup of gas may rupture the pellet (unlikely) but is highly unlikely to come close to rupturing a canister.

Perhaps if he actually took the time and performed academic calculations instead of schoolboy ones...

(I can't link to it but if you are interested you should be able to find a peer reviewed study of the issue in the Journal of Nuclear Materials (407 2010), by Cecile Ferry, et. al., "Effect of helium on the microstructure of spent fuel in a repository: An operational approach.")