Thorium Nuclear Reactors

[mosaix]

I'd read a science-fact article about Thorium Reactors in Analog a few years ago and wondered then why no one had thought they were worthwhile. Apparently they are 'safe' and there is a plentiful supply of raw material.

China is taking the lead on the technology.

Safe nuclear does exist, and China is leading the way with thorium - Telegraph

US physicists in the late 1940s explored thorium fuel for power. It has a higher neutron yield than uranium, a better fission rating, longer fuel cycles, and does not require the extra cost of isotope separation

The plans were shelved because thorium does not produce plutonium for bombs.

The UK has already put its efforts into the next generation of uranium reactors. Yet critics say vested interests with sunk costs in uranium technology succeeded in chilling enthusiasm.

The same happened a decade ago to a parallel project by Nobel laureate Carlo Rubbia at CERN (European Organization for Nuclear Research).

France’s nuclear industry killed proposals for funding from Brussels, though a French group is now working on thorium in Grenoble.


I would have thought, in the aftermath of Fukushima, that here is an excellent opportunity for the UK to get involved at an early stage in promising technology and may be a better investment of scarce funds than, say, HS2.

 

[Dr Zoidberg]

Interesting stuff. That sounds pretty promising.

 

[Ursa major]

Just to point out that, in regard to your comment about HS2, in the absence of battery or hydrogen powered cars, the best way to use electricity (whether generated from Thorium Reactors or not) for transport is an electrified railway; and increasing the capacity of the network is necessary, particularly on the West Coast Mainline (whose last upgrade cost £9+billion, I believe), which is already a quadruple tracked route from London as far north as Crewe, leaving little room for further expansion.

Note also that the granddaddy of all the high speed projects outside Japan, the Paris-Lyon TGV, originally emerged from a desire to increase the capacity on SNCF's normal-speed network, mostly to make room for more freight. By siphoning off a lot of the passenger traffic onto the fast line(s), that's what has happened. Of course, all the interest focuses on the speed and the power of the trainsets and that sort of thing. (Even Wiki isn't immune from this narrow viewpoint, to the extent that the word, freight, only appears in the context of carrying it on the fast line.) But that's not why the TGV was built, and it's not why HS2 needs to be built.

 

[Foxbat]

There have been a few experimental Thorium reactors over the years (last I heard of was South African Pebble Reactor).
Thorium has very little fissile material (why it is safer) and cannot sustain a chain reaction. It needs constant bombardment of Neutrons from another source. I'm only guessing but I would imagine these problems would lead to a lower power output than other forms of reactors.

On the safety side - similar claims were made about the UK AGR programme after Chernobyl (gas being subject to convectional currents even if circulation is lost) but it still died a death because the system was just too expensive.

I think if this system does happen, we could see two or three Thorium reactors needed to produce the output of one using Uranium (incidentally a by product of the Thorium reactor but wrong isotope...233)

 

[mosaix]

Just to point out that, in regard to your comment about HS2, in the absence of battery or hydrogen powered cars, the best way to use electricity (whether generated from Thorium Reactors or not) for transport is an electrified railway; and increasing the capacity of the network is necessary, particularly on the West Coast Mainline (whose last upgrade cost £9+billion, I believe), which is already a quadruple tracked route from London as far north as Crewe, leaving little room for further expansion.

Note also that the granddaddy of all the high speed projects outside Japan, the Paris-Lyon TGV, originally emerged from a desire to increase the capacity on SNCF's normal-speed network, mostly to make room for more freight. By siphoning off a lot of the passenger traffic onto the fast line(s), that's what has happened. Of course, all the interest focuses on the speed and the power of the trainsets and that sort of thing. (Even Wiki isn't immune from this narrow viewpoint, to the extent that the word, freight, only appears in the context of carrying it on the fast line.) But that's not why the TGV was built, and it's not why HS2 needs to be built.

The whole HS2 argument and why it may or may not be needed as work patterns change in the next 20 or 30 years is the subject of another debate.

 

[Ursa major]

True, but I couldn't let your off-hand remark about how the money for it ought to be diverted to thorium reactor research. It isn't as if other budgets don't deserve looking at first. (And whatever the work patterns - as it happens, the people I know travel to work far farther now than they did, say, twenty years ago - we should be trying to get freight off the roads whenever possible.)

 

[mosaix]

True, but I couldn't let your off-hand remark about how the money for it ought to be diverted to thorium reactor research. It isn't as if other budgets don't deserve looking at first. (And whatever the work patterns - as it happens, the people I know travel to work far farther now than they did, say, twenty years ago - we should be trying to get freight off the roads whenever possible.)

Off-hand to you maybe, and I did use the words 'may be' rather than 'ought to'.

 

[Ursa major]

Also true. Sorry.


(But you did single out HS2, another real investment - because we'll have something to show for spending the money - rather than often wasteful projects whose supporters would have trouble calling investments. Now that we seem to be backing off from, say, bombing or occupying distant lands, there'll be more money for worthwhile projects back home.)

 

[mosaix]

No probs, UM.

 

[Mirannan]

I'm not sure about this, but AFAIK the biggest problem with thorium as a reactor fuel is that thorium is not in itself fissile. This means that a thorium reactor, every time it's refuelled, will have to have some fissile material mixed in with it. (Of course, this could be thorium-derived U233 once the thorium fuel cycle is established.) Initially, this would have to be plutonium-239 or partially enriched uranium.

Incidentally, it's not quite true that thorium reactors can't be used to make bomb material. It's just damn difficult and potentially extremely hazardous.

This is because although U233 would make good bomb material, in an actual reactor some U232 is formed; and U232 is extremely hazardous (producing high-energy gamma rays) and unsuitable for use in bombs because the gamma rays are strong enough to damage bomb electronics.

 

[ed9428]

I'm always suspicious when promising technology is lost or "forgotten", especially when government is involved.

But I also might be a little bit crazy.

 

[Starbeast]

Great info about THORIUM

link - THE THORIUM PROBLEM - Danger of existing thorium regulation to U.S. manufacturing and energy sector - YouTube​