Thorium 232-Uranium 233 Nuclear Energy. No Route to Weapons Grade Fissile M

[SanddancerUSA]

Thorium 232 nuclear reactors. No route to weapons grade fissile material so this technology has been almost completely ignored by all parties.

I consider myself fairly well read regarding science and technology. So how come i missed this?

http://pubs.acs.org/cen/science/87/8746sci2.html

http://en.wikipedia.org/wiki/Thorium

Get ya fingers out people.

[Statistical]

1. Main reason is economics.

Thorium has no isotope that can achieve criticality on its own. Thus you can never have a pure Th232 cycle.



(Hopefully wiki won't mind me leeching their image.)

Notice an initial neutron is needed, but TH232 never emits neutrons. So a Thorium reactor either needs
a) some uranium-235 "seed" fuel
b) massive neutron generator (increases cost & complexity)

The second issue is a very high burnup rate is required for Thorium fuel to remain "neutron rich". The cycle produces less thermal neutrons than U235 cycle. While this is possible it is harder to achieve commercially (cost) and also was much harder to acheive circa 1960. Also in 1960s we were looking for weapons grade production so that is where research was focused.

PWR can be adapted to Th232 but it isn't optimal. We have decades of research in PWR so there is reluctance for companies to drop all that and take a massive risk and try to commercialize molten salt Th232 reactor or some other exotic design.

U235 cycle "just works".

Current reactors can use a thorium fuel cycle but it does require some significant modification and for the time being U238 is more economical. Turning soviet warheads into MOX has lengthened the U238 lifespan. Even doubling or tripling price of U238 would only result in a small increase in overall electrical generaiton costs (<10%).

However going forward demand will likely exceed capacity of U238 in a couple decades this will require either
a) reprocessing (currently about 3x as expensive an enriching new uranium)
b) thorium fuel cycle
c) fast breeder reactors

There is less weapon risk with b but nuclear device can be made from U232. The combination of higher burnup rate and natural abundance means we have enough Thorium fuel for about 100+ years of electrical generation even if we quadruple nuclear capacity.

India is heavily focused on Th because they have large amounts of it but <1% of worldwide uranium supply.