An interesting doc on Thorium Nuclear Power.

Lifted from Wikipedia....

Thorium-based nuclear power is nuclear reactor-based electrical power generation fueled primarily by the nuclear fission of the isotope uranium-233 produced from the fertile element thorium. According to proponents, a thorium fuel cycle offers several potential advantages over a uranium fuel cycle—including much greater abundance on Earth, superior physical and nuclear fuel properties, and reduced nuclear waste production. However, development of thorium power has significant start-up costs. Proponents also cite the lack of weaponization potential as an advantage of thorium, while critics say that development of breeder reactors in general (including thorium reactors that are breeders by nature) increase proliferation concerns. Since about 2008, nuclear energy experts have become more interested in thorium to supply nuclear fuel in place of uranium to generate nuclear power. This renewed interest has been highlighted in a number of scientific conferences, the latest of which, ThEC13 ^[1] was held at CERN by iThEC and attracted over 200 scientists from 32 countries.

A nuclear reactor consumes certain specific fissile isotopes to produce energy. The three most practical types of nuclear reactor fuel are:

• Uranium-235, purified (i.e. "enriched") by reducing the amount of uranium-238 in natural mined uranium. Most nuclear power has been generated using low-enriched uranium (LEU), whereas high-enriched uranium (HEU) is necessary for weapons.
• Plutonium-239, transmuted from uranium-238 obtained from natural mined uranium. Plutonium is also used for weapons.
• Uranium-233, transmuted from thorium-232, derived from natural mined thorium. This is the subject of this article.

Some believe thorium is key to developing a new generation of cleaner, safer nuclear power.^[2] According to an opinion piece by a group of scientists at the Georgia Institute of Technology, considering its overall potential, thorium-based power "can mean a 1000+ year solution or a quality low-carbon bridge to truly sustainable energy sources solving a huge portion of mankind’s negative environmental impact."^[3]

After studying the feasibility of using thorium, nuclear scientists Ralph W. Moir and Edward Teller suggested that thorium nuclear research should be restarted after a three-decade shutdown and that a small prototype plant should be built.^[4][5][6] Research and development of thorium-based nuclear reactors, primarily the liquid fluoride thorium reactor, (LFTR), MSR design, has been or is now being done in India, China, Norway, United States, Israel and Russia.

The Wikipedia article seems to provide a measured statement of the viability, benefits and risks of looking to thorium as a fuel for nuclear energy. But it might need updating.

"Some believe thorium is key to developing a new generation of cleaner, safer nuclear power."

No, that's fusion (H+H, H+D, or H+He in order of preference).  The only really damaging material produced, and then only in the case of an accident, would be caused by fission of a portion of the heavier materials used in the construction of the plant (electrical conductors, magnets etc) due to the extreme conditions of an accident (particularly the neutron flux)

OK, in the case of H+He, the Lithium produced is quite damaging, but nowhere near as bad as the cesium, francium, iodine and other radioisotopes of a fission reactor (even thorium).

I'm not entirely clear what your "No" refers to at the start of para 2 ?

George posted a mere link to an article, a practice that I find irritating, so I simply copied a chunk out of Wikipedia (warts and all) to give other readers an overview of what Thorium was about. My only contribution was the final paragraph.

If Wikipedia says "Some believe thorium is key........" then I am inclined to believe that "Some believe..............." That doesn't mean that "All" believe or, more specifically the "Huge" believes......

My mate who works a Culham says that fusion can now be kept going for a couple of seconds, rather than a few nano-seconds, i'm not sure what he means by "kept going" but it doesn't sound too promising that fusion based energy will be with us before the end of this year.............?

Dear Don,

On the whole I agree that my initial post was somewhat lacking. but it is a subject I am interested in. Water cooled nuclear power stations rely on pressurised water. Thorium reactors would rely on non pressurised systems ... and would naturally shut down in the event of catastrophic failure ...

The human race needs to release a  relatively safe  source of energy that can generate electricity for heat light and personal transport as well home entertainment ...

I just thought that the previous work on Thorium might be an interesting discussion point.

ATB from George

George Fredrik Fiske posted:

Dear Don,

On the whole I agree that my initial post was somewhat lacking. but it is a subject I am interested in. Water cooled nuclear power stations rely on pressurised water. Thorium reactors would rely on non pressurised systems ... and would naturally shut down in the event of catastrophic failure ...

The human race needs to release a  relatively safe  source of energy that can generate electricity for heat light and personal transport as well home entertainment ...

I just thought that the previous work on Thorium might be an interesting discussion point.

ATB from George

I agree. and I am only mildly irritated when people only post a link to an interesting subject, rather than posting even a brief executive summary.........

Don Atkinson posted:

I'm not entirely clear what your "No" refers to at the start of para 2 ?

George posted a mere link to an article, a practice that I find irritating, so I simply copied a chunk out of Wikipedia (warts and all) to give other readers an overview of what Thorium was about. My only contribution was the final paragraph.

If Wikipedia says "Some believe thorium is key........" then I am inclined to believe that "Some believe..............." That doesn't mean that "All" believe or, more specifically the "Huge" believes......

My mate who works a Culham says that fusion can now be kept going for a couple of seconds, rather than a few nano-seconds, i'm not sure what he means by "kept going" but it doesn't sound too promising that fusion based energy will be with us before the end of this year.............?

Hi Don,

Despite your first para, you clearly indicate that you understood that the 'No' referred to the quoted sentence.

As you also indicate that you understood, that I'm not throwing doubt on the fact that some people believe that "thorium" reactors (N.B. you can't actually use thorium for fission - see comment 1 below) would be safer - after all some people believe that the moon landings never happened and that the world is flat (I actually know someone like that ).  I accept that my language could have been clearer; please excuse that, I currently have concentration problems as my autonomic nervous system is a bit disturbed (biased to the parasympathetic) and I have language issues anyway - it's not a good combination.

I don't believe thorium would be safer, as:

1  The fissile material you'd have to produce to drive the reactor isn't thorium but uranium(233)
2  Unconverted Pa(233) is included in the waste and this is known to be a particularly dangerous isotope
3  Many of the fission products of U(233) have longer half lives than those of U(235)
4  U(233) produces significant amounts of I(129) as a fission product which is particularly dangerous due to iodine's biological role.
5  The coolant circuit runs at between 600°C and 800°C (fused mixed halide salts)
6  You can produce plutonium from U(238) in a "thorium" reactor, simply by placing the U(238) inside the containment vessel.  This can then be extracted to yield weapons grade plutonium.

You are right, that continuous fusion hasn't been achieved, only a few seconds (but they are now well beyond parity): it's an engineering problem yet to be solved.  On the other hand there hasn't been a production scale "thorium" reactor built either: so that's also an engineering problem yet to be solved!

What many people fail to realise is that nuclear power is already (by far) the safest form of power generation we have. Safer than even wind and solar. Three of orders of magnitude safer than coal.

Energy Source               Mortality Rate (deaths/trillionkWhr)

Coal – global average         170,000    (50% global electricity)

Coal – China                         280,000   (75% China’s electricity)

Coal – U.S.                               15,000    (44% U.S. electricity)

Oil                                               36,000    (36% of energy, 8% of electricity)

Natural Gas                                4,000    (20% global electricity)

Biofuel/Biomass                    24,000    (21% global energy)

Solar (rooftop)                              440    (< 1% global electricity)

Wind                                                 150    (~ 1% global electricity)

Hydro – global average          1,400    (15% global electricity)

http://www.forbes.com/sites/ja...e4857a0b40446b0b49d2

Nice link winky.

It still raises as many questions as it provides answers (as George said in his initial post), but it's a good starting point and I doubt if we could ever answer all the relevant questions even if we could get rid of the politicians and only deal with honest scientists, engineers and accountants.

Energy Source               Mortality Rate (deaths/trillionkWhr)

Coal – global average         170,000    (50% global electricity)

Oil                                               36,000    (8% of electricity)

Natural Gas                                4,000    (20% global electricity)

Hydro – global average          1,400    (15% global electricity)

Solar (rooftop)                              440    (< 1% global electricity)

Wind                                                 150    (~ 1% global electricity)

The starting point must be "can we afford to provide electricity via the nuclear route". I am guessing that coal is significantly cheaper and so too with oil, gas and hydro. OTOH, hydro is somewhat limited (at least in the UK).

Don Atkinson posted:

Nice link winky.

It still raises as many questions as it provides answers (as George said in his initial post), but it's a good starting point and I doubt if we could ever answer all the relevant questions even if we could get rid of the politicians and only deal with honest scientists, engineers and accountants.

Energy Source               Mortality Rate (deaths/trillionkWhr)

Coal – global average         170,000    (50% global electricity)

Oil                                               36,000    (8% of electricity)

Natural Gas                                4,000    (20% global electricity)

Hydro – global average          1,400    (15% global electricity)

Solar (rooftop)                              440    (< 1% global electricity)

Wind                                                 150    (~ 1% global electricity)

Nuclear – global average          90    (17%  global electricity w/Chern&Fukush)

The starting point must be "can we afford to provide electricity via the nuclear route". I am guessing that coal is significantly cheaper and so too with oil, gas and hydro. OTOH, hydro is somewhat limited (at least in the UK).

If all forms of generation were regulated so as to be as safe as nuclear then it would likely be one of the cheapest options.

Willy.

Willy posted:

Don Atkinson posted:

Nice link winky.

It still raises as many questions as it provides answers (as George said in his initial post), but it's a good starting point and I doubt if we could ever answer all the relevant questions even if we could get rid of the politicians and only deal with honest scientists, engineers and accountants.

Energy Source               Mortality Rate (deaths/trillionkWhr)

Coal – global average         170,000    (50% global electricity)

Oil                                               36,000    (8% of electricity)

Natural Gas                                4,000    (20% global electricity)

Hydro – global average          1,400    (15% global electricity)

Solar (rooftop)                              440    (< 1% global electricity)

Wind                                                 150    (~ 1% global electricity)

Nuclear – global average          90    (17%  global electricity w/Chern&Fukush)

The starting point must be "can we afford to provide electricity via the nuclear route". I am guessing that coal is significantly cheaper and so too with oil, gas and hydro. OTOH, hydro is somewhat limited (at least in the UK).

If all forms of generation were regulated so as to be as safe as nuclear then it would likely be one of the cheapest options.

Willy.

True, but I rather suspect that coal, for instance, is heavily populated with deaths in coal mines and people breathing polluted air, rather than shovelling coal into power stations or building power stations.

OTOH, if we looked at the equivalent figures for electricity generation in the "developed" world eg N America, Western Europe, Austaraisia and Japan, we might get a clearer picture of the "potential" mortality rates of each energy source.

Perhaps winky can provide the data ?

The death rate for hydroelectricity is skewed by the single but catastrophic accident (170,000 deaths) at the Banqiao Reservoir Dam in China in 1975, as shown in the data below from theenergycollective.com:

Energy Source Mortality Rates; Deaths/yr/TWh

Coal - world average, 161

Coal - China, 278

Coal - USA, 15

Oil - 36

Natural Gas - 4

Biofuel/Biomass - 12

Peat - 12

Solar/rooftop - 0.44-0.83

Wind - 0.15

Hydro - world, 0.10

Hydro - world*, 1.4

Nuclear - 0.04

 * Includes the 170,000 deaths from the failure of the Banqiao Reservoir Dam in China in 1975

Looked at from a cost point of view, hydroelectric is the cheapest for operating costs, high on maintenance costs and nil on fuel costs.... provided you have the water. On average about a third of the cost of nuclear power.

The table is complex to copy here, but easy to link to

http://www.eia.gov/electricity.../html/epa_08_04.html

Banqiao Dam Disaster

The UK has maxed-out its hydro schemes, including the pumped water storage sites. If other sites exist, I'm pretty sure the "environmentalists" would scupper any more flooded valleys !

Here in the UK I consider we should invest in nuclear stations to replace the coal stations as we decommission them. And until we commission the new nuclear ones, we shouldn't de-commission the existing coal ones.

I also consider that as and when we build renewable energy sites (wind and solar a present) we should also build storage sites so that the renewable energy sites are effectively able to supply power when it is needed, rather than when it is available.

Don Atkinson posted:

Here in the UK I consider we should invest in nuclear stations to replace the coal stations as we decommission them. And until we commission the new nuclear ones, we shouldn't de-commission the existing coal ones.

I'm not sure that is feasible to maintain UK power "independence" within the time scale of nuclear plant build  cycles & the projected needs for UK power over the next two decades.    At the moment wherever feasible decommissioned coal stations are being converted to Biomass,  but we don't have enough bio-anything-fuel to replace the decommissioned coal GW.   The other solution that achieves more power than we need & can be done in a fraction of the time to commission a nuclear plant, is CCGT.  We are sitting on many hundreds of years of gas,  probably the worlds largest gas reserve.   However the bad (wrong) public knowledge/fear/opinion of fracking will probably mean we will never use it & we will continue to be held to ransom by Russia & buy their fracked gas instead.

Don Atkinson posted:

Willy posted:

Don Atkinson posted:

Nice link winky.

It still raises as many questions as it provides answers (as George said in his initial post), but it's a good starting point and I doubt if we could ever answer all the relevant questions even if we could get rid of the politicians and only deal with honest scientists, engineers and accountants.

Energy Source               Mortality Rate (deaths/trillionkWhr)

Coal – global average         170,000    (50% global electricity)

Oil                                               36,000    (8% of electricity)

Natural Gas                                4,000    (20% global electricity)

Hydro – global average          1,400    (15% global electricity)

Solar (rooftop)                              440    (< 1% global electricity)

Wind                                                 150    (~ 1% global electricity)

Nuclear – global average          90    (17%  global electricity w/Chern&Fukush)

The starting point must be "can we afford to provide electricity via the nuclear route". I am guessing that coal is significantly cheaper and so too with oil, gas and hydro. OTOH, hydro is somewhat limited (at least in the UK).

If all forms of generation were regulated so as to be as safe as nuclear then it would likely be one of the cheapest options.

Willy.

True, but I rather suspect that coal, for instance, is heavily populated with deaths in coal mines and people breathing polluted air, rather than shovelling coal into power stations or building power stations.

OTOH, if we looked at the equivalent figures for electricity generation in the "developed" world eg N America, Western Europe, Austaraisia and Japan, we might get a clearer picture of the "potential" mortality rates of each energy source.

Perhaps winky can provide the data ?

My original table has coal for the US at a mortality rate of 15,000 deaths per trillionkWhr, compared to nuclear at 90. OK, it's 10 times better than the global average (heavily affected by China and India), but is still 150 times worse than nuclear. Yes, a lot of those deaths come from the mining process and pollution effects, even in the US. Building and/or running a coal-fired power plant in the US is perhaps not particularly dangerous from an industrial safety perspective. The whole system is correctly considered in each case.

Thanks winky, I imagine the US figures are fairly typical of the potential minimum death rate for coal. Presumably carbon capture technology would make coal a bit more attractive (and a bit more expensive).

I'm not sure how these would compare with fracked gas powered power stations.

When I used to provide consultancy services to the transport industry, ISTR that when comparing options, risk of death or serious injury was taken into account by valuing a life at c.£3m (there were different figures in the airline industry and the railway industry and I might be miles out, it was some time ago). Society seems willing to accept that cheaper options are acceptable providing the death/injury rate isn't too large.

Since nuclear seems to be less expensive than Wind or solar (at least in the UK), it seems to look like a no-brainer to me. I'm not sure about the situation with fracked gas, perhaps Mike has some info ?