Thorium nuclear energy?

[aeolium]

Today I happened to listen to a R4 programme on the use of thorium as an alternative to uranium as the basis for a new generation of nuclear reactors. There seemed to be a number of advantages to thorium - not least the fact that it is much more widespread and that its waste is supposedly less dangerous than that from uranium nuclear reactors. On the other hand, thorium-based nuclear energy technology is much less developed than uranium-based technology. Here is a recent report on Indian plans for thorium-based nuclear power.

Can any knowledgeable scientists on here shed light on the pros and cons of thorium-based nuclear energy production for a science ignoramus like me?

[aka Calum Da Jazbo]

er this ignoramus wishes to confess his enthusiasm for thorium nuclear energy on the basis of his own reading but will leave all to the far more expert boredees

[teamsaint]

The only explanation I have ever seen for not developing and using thorium reactors, is the lack of weapons grade plutonium produced.

Which explains a lot, really.

Other cheap energy sources are probably suppressed also.

[amateur51]

The only explanation I have ever seen for not developing and using thorium reactors, is the lack of weapons grade plutonium produced.

Which explains a lot, really.

Other cheap energy sources are probably suppressed also.

I'm with Calum and I suspect that teamsaint has hit upon the snag - which looks like a major positive to me

[Lateralthinking1]

We were here briefly in relation to Japan. I'm completely anti nuclear - done enough of that discussion already - but if we have to have it, I would choose thorium. We won't get it for the reasons stated. frances_iom is one who would have all the info.

[PhilipT]

The only explanation I have ever seen for not developing and using thorium reactors, is the lack of weapons grade plutonium produced.

Which explains a lot, really.

Other cheap energy sources are probably suppressed also.

It's certainly true that at first the main driver for building uranium reactors was to produce plutonium for weapons. This is the case for Britain's Magnox reactors, and the North Korean design which copied them. However, the trouble with thorium reactors is that to get them going you need a source of thermal neutrons; in other words, a fission reactor. So you have to start your reactor with U-235 anyway, in which case why bother with the thorium? [Technical aside: Th-232 (the only natural isotope) absorbs a neutron to produce Th-233, which decays by two beta decays to U-233, which *is* fissile, given a second neutron. U-235, by contrast, is very slightly naturally fissile on its own without an incident neutron, which is how nuclear power stations can start up from cold.]

Perhaps you'd like to suggest what other cheap energy sources might be being suppressed?

[teamsaint]

It's certainly true that at first the main driver for building uranium reactors was to produce plutonium for weapons. This is the case for Britain's Magnox reactors, and the North Korean design which copied them. However, the trouble with thorium reactors is that to get them going you need a source of thermal neutrons; in other words, a fission reactor. So you have to start your reactor with U-235 anyway, in which case why bother with the thorium? [Technical aside: Th-232 (the only natural isotope) absorbs a neutron to produce Th-233, which decays by two beta decays to U-233, which *is* fissile, given a second neutron. U-235, by contrast, is very slightly naturally fissile on its own without an incident neutron, which is how nuclear power stations can start up from cold.

Perhaps you'd like to suggest what other cheap energy sources might be being suppressed?

Thanks for that.........I think !!
No I wouldn't really like to suggest which sources might be being suppressed. I just put the idea out for others to look at if they wish.
All I would say is that it strikes me as a bit odd that we are still using internal combustion engines however long it is after they were invented...and that half of the worlds economic an political problems seem to revolve around oil.

[teamsaint]

[QUOTE=PhilipT;135916]It's certainly true that at first the main driver for building uranium reactors was to produce plutonium for weapons. This is the case for Britain's Magnox reactors, and the North Korean design which copied them. However, the trouble with thorium reactors is that to get them going you need a source of thermal neutrons; in other words, a fission reactor. So you have to start your reactor with U-235 anyway, in which case why bother with the thorium? [Technical aside: Th-232 (the only natural isotope) absorbs a neutron to produce Th-233, which decays by two beta decays to U-233, which *is* fissile, given a second neutron. U-235, by contrast, is very slightly naturally fissile on its own without an incident neutron, which is how nuclear power stations can start up from cold.]

In your opinion, is there a comparable quantity of weapons grade plutonium produced in the different processes?

[Frances_iom]

India I believe is pushing Thorium having easy access to it but its initial design uses a plutonium core - the wikipedia article http://en.wikipedia.org/wiki/Thorium seems succint and complete - there is much interest in the moltern salt reactor designs as appear inherently stable as well as usable in more specialised applications.

Re oil - catch is no one has invented a more convenient portable fuel with such high energy density + the century or so experience in building and operating the infrastructure to provide it. There are many current uses that could be replaced (eg domestic use of gas by nuclear electricity), railway transport and metropolitan transport by electric vehicles but hydrocarbons look to remain dominant in other modes of transport.

[Lateralthinking1]

frances_iom and PhilipT - Interesting. I have a few questions:

- Could it not be said that wave power is being suppressed if adequate money isn't put into research?
- How do we categorise fracking, other than controversial and often locally suppressed?
- Notwithstanding the U-235 matter and other points, I thought I read that the UK has masses of thorium?
- How quickly could molten salt reactors be used? Could we not wait to build new plants so that we can have those?

[Frances_iom]

depends on when you expect to start to see power cuts - too little investment in infrastructure already - the current recession has given a small breathing space but need both new transmission links (you don't get much wave power in the home counties tho plenty of unusable hot air seems to be generated there) + generators - thorium reactors + wave power in capacities we need to replace ageing coal + nuclear are still some way off.. However I guess we could dispense with what ever industry we have left and return to domestic energy consumption of the 19th C - should be good for tourism in that the Chinese can come and see real Dickensian conditions .

[Lateralthinking1]

depends on when you expect to start to see power cuts - too little investment in infrastructure already - the current recession has given a small breathing space but need both new transmission links (you don't get much wave power in the home counties tho plenty of unusable hot air seems to be generated there) + generators - thorium reactors + wave power in capacities we need to replace ageing coal + nuclear are still some way off.. However I guess we could dispense with what ever industry we have left and return to domestic energy consumption of the 19th C - should be good for tourism in that the Chinese can come and see real Dickensian conditions .

Yes thank you. I am extremely encouraged that the view from the Irish (Manx) Sea is that the recession will provide only a small breathing space.

[teamsaint]

depends on when you expect to start to see power cuts - too little investment in infrastructure already - the current recession has given a small breathing space but need both new transmission links (you don't get much wave power in the home counties tho plenty of unusable hot air seems to be generated there) + generators - thorium reactors + wave power in capacities we need to replace ageing coal + nuclear are still some way off.. However I guess we could dispense with what ever industry we have left and return to domestic energy consumption of the 19th C - should be good for tourism in that the Chinese can come and see real Dickensian conditions .

It is time that governments stopped threatening us with the kind of scenario that you(probably quite rightly) suggest, and started investing in clean, safe, affordable power.
They choose not to.
In the meantime, carbon capture coal is an option.Fukushima was pretty ugly.

[Flay]

...clean, safe, affordable power...
...pretty ugly.

Two oxymorons in one post. Very good!

[Serial_Apologist]

Perhaps you'd like to suggest what other cheap energy sources might be being suppressed?

As one who has naively tried to ignite wood chips using just a match, then newspaper, but no accelerant of any kind, the fire at the Tilbury power station raised a few such questions in my mind...