4、We can then look at uranium 238 which has a relatively low absorption thermal energy range and essentially has no fission cross section which is why we call uranium 238 a fertile atom.
1、And you can see a very high energy as uranium 238 does have a fission cross section which in some ways can be used in fast reactors.
3、And then of course as part of the absorption we have a fission cross section which, as I said earlier, is what we want to focus on so we can make some power and some heat.
2、So if you take a certain volume and you have a certain amount of material, let's just take the fission cross section as the issue.
