Fuel on a Friday - 10 Facts

I can’t believe it’s Friday already. 

This week has just gone by so fast. It started with Alexandra still being sick on Monday, and then on Tuesday I went to Stavanger, and spent around 50 hours there - giving two talks, and talking to so many interesting people. (I think I’ll have to write about some of my thoughts about the Norwegian oil industry - just not right now.) Yesterday I got home, and the evening was spent with Anders; we shared a bottle of wine, he worked on his code and I scanned all my receipts from the trip, and sorted them into the right folders (not fun doing, but it feels GREAT when you’re done, especially when you realise you’ve spent roughly 9000NOK on travelling, that you of course want, and will get, back ;)). Then we made the working your ass off thai chili, and around that time I got a migraine…:/ 

However, today is Friday, and luckily I woke up this morning feeling great again - hopefully there'll be many months before I get another migraine attack!

So Friday is luckily NOT equal to migraine, but it IS equal to FACTS! It's finally time for ten Friday Facts about Fuel - nuclear fuel, of course:

1. the fuel in a nuclear power plant is placed inside the reactor core. Mostly all the fuel soaked in water because water is great for cooling the fuel, which is the same as removing the heat - which is exactly what we want; we want water to be heated so that we can produce steam and thus generate electricity with a turbine <3
2. we often call it "burning" the fuel, but it's no real burning going on - the fuel is the place where the fission chain reaction happens (the energy from nuclear power comes from fission of nuclei inside the fuel :) ), so when I talk about (nuclear) fuel I mean material where there’s a chain reaction going on.
3. nuclear fuel is made out of slightly radioactive elements; it can either be uranium, plutonium, or thorium
4. a small part of the fuel has to be fissile; meaning it has to have a really big chance of splitting if it's hit by a neutron. The fissile material can be either uranium-233, uranium-235, or plutonium-239
5. thorium is NOT fissile, so thorium must be mixed with something that is. This means that in thorium based fuels it is actually not the nuclei of the thorium atoms itself that fissions - thorium is first transformed into uranium-233, and then this uranium nucleus is the one that fissions and releases energy :D
6. the fissile part of the fuel is typically just 5% of the total of the fuel. The rest of the fuel (so, the majority of the fuel, really) is either thorium-232 or uranium-238.
7. the "flame" in nuclear fuel is the neutron. There is of course no real flame, and there is also no burning (see point number 2.), but I think that calling the neutron "the flame" is a nice analogy, since the neutron is what makes the nucleus fission and then release all the energy <3
8. the most common nuclear fuel is called UOX, which is for uranium oxide, meaning that it’s not pure metallic uranium (uranium as an element is a metal), but uranium and oxygen ( the oxides are used rather than the metals themselves because the oxide melting point is much higher than that of the metal and because it cannot actually burn, since it's already in the oxidized state.)
9. used fuel can (and should, in my opinion!) be recycled, since it has a lot of material that is really useful (actually: typically only half a percent of all the fuel fissions during the years it's in the reactor, so if you throw away all that's left after a couple of years, you throw away A LOT of resources). If you recycle these materials - which can be uranium-235 that just hasn't fissioned yet, or plutonium-239 that has been made during the time the fuel was in the reactor - you have to mix them with fresh fissile material, and when you do this the fuel is called MOX. MOX is short for Mixed Oxides :D
10. if you get really got at recycling, and you have the kind of reactors that are optimized for this type of MOX fuel (see point number 9.), you can actually end up getting 200 times more energy from the fuel than you normally get today!

- my fuel when I got to Stavanger airport yesterday: Chablis and Cæsar salad - as I started going through all the receipts (a lot!) rom just two days travelling -