What is the link between nuclear weapons and nuclear power stations?

Utwig

Hi

The link really centres around a kind of reactor called a breeder or fast breeder reactor. In general, we use U235 to produce power, and also to make weapons with. U235 is refined from an ore called yellow cake via gas centrifuges usually linked together in series, so the output of one is the input of the next. The problem is that there is a finite amount of U235 available, and its a pain to refine.

There is another material U238, that is far more abundant but can’t really be used in its native or refined state to produce power or weapons, but, and its a big but, if you place staves of the stuff around a U235 fission pile the effect of the neutron bombardment it is subjected to turns it into something else, plutonium.

We can make power from plutonium, but its a hideously toxic material and to be honest, you don’t really want to have anything to do with it. The sad fact though is that its really really good at making unbelievably lethal bombs. As you have probably guessed, the kind of reactor space used for this purpose is a breeder reactor, where staves of U238 are arranged near the U235 core for precisely the purpose of manufacturing plutonium, and that is your link.

Hope this helps.

Utwig

Astronuc

Yellow cake (oxide) is converted to UF₆, which is used in centrifuges where is is a gas. Enriched UF₆ (that is up to 4.95% U-235) is sent to commercial nuclear fuel plants where it is converted into an oxide, ultimately in the form of ceramic pellets which are then encapsulated in Zr-alloy cylindrical tubing, and hermetically sealed with Zr-alloy endplugs (Zr-alloy barstock).

For the naval program, the enrichment is much higher, and that value is classified. Naval reactor fuel is quite different from commercial fuel.

Nuclear weapons are predominantly based on Pu-239 which is produced from U-238 in special production reactors, which are not necessarily fast breeder reactors.

U-235 based weapons have been phased out.

Utwig

Hi,

Yep, I have no doubt plutonium can be made in other kinds of reactor, but I've only really ever had experience with the breeder type, and pressurised water kind. I could have put down a lot more detail, but was really only trying to highlight the link between commercial power generation and instant sunshine machines in layman's terms.

My personal fave was he pressurised water reactor, during the time I was involved with them we refuelled 2 boats and pulled the solid relief's out of 4 more. Its amazing how small the reactor actually is, once you pull all the boron impregnated polythene off one its not much longer than a family car and maybe about half a meter in diameter. Stunning how something so small can put out so much heat. It wasn't often we had to enter a reactor space while the pile was in plant state A but the odd time we did, if the blowers were not on it was uber hot. Oh, incidentally the exp with breeders didn't involve working on them but was more along the lines of getting the monitoring certification completed.

Utwig

Utwig