Thorium third Round Testing

Foxbat

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#1
Third round Thorium Oxide testing has begun on two fuel pins at the Halden research reactor in Norway. Continuous monitoring of a special fuel plug containing the two pins will tell whether it can be safely used.

One question about Thorium and its use that's puzzled me is how to actually get it going considering that it is less active than Uranium. The answer here is that the fuel pellet has a 10% mix of Plutonium as a 'fissile driver'.

Next problem- using Thorium in a reactor can produce Uranium 232, which emits high energy gamma rays as part of its decay chain. This is a significant hazard to workers on any plant of this nature and either large amounts of shielding or another method of control will have to be found. Apparently the process can be controlled by removal of protactinium 233 during the decay process. How this would be done in practical terms is beyond me.:(

Still, I think the biggest benefit of a Thorium reactor is the fact that it is extremely difficult to make bombs from its decay products. This would open up an abundance of power (three times more abundant than Uranium) without being a significant threat to the Nuclear Proliferation Treaty.:)

Third round of thorium test irradiation starts
 

Foxbat

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#4
Maybe, but if it requires a supply of plutonium in the first place ... :)
Yes, but the fuel could be manufactured under controlled conditions. A third world country for example could have a Thorium reactor built and the fuel supplied by another country (part of Euratom or some other controlled body).

The pellets are very small (a few centimetres in length) and come as an Oxide paste encased within a cladding. It is very difficult to make this paste and even more difficult to separate, which is why the UK spent billions on THORP (Thermal Oxide Reprocessing) only to find it to be pretty inefficient (yielding around 1 per cent Plutonium from 96 percent irradiated Uranium).

If a country had the tech to improve on this then they'd probably already have the bomb. Furthermore Plutonium239, when irradiated, becomes Uranium 235 as part of its decay chain. This is why the Fast Breeder reactor was experimented with (Uranium to Plutonium in conventional reactor, Plutonium to Uranium in Fast Breeder...and this Uranium going back to make conventional nuclear fuel). So any Thorium reactor would exhaust the Plutonium seeded within the Thorium Oxide.
 

Venusian Broon

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Question is though, will a working Thorium reactor ever be economical? It's clearly going to require significant R&D (I suppose a bit like fusion - a good pitch in theory, but in practice the technical details are hampering it) So the main commercial power providers are scared away from the investment, so that's only going to come from government subsidy, research and investment (and a lot of it).

And all the time the cost of renewables is dropping through the floor. And this is with much less support from governments (Clearly such tech would be better and cost less if governments had pushed it with the same vigour.)

Sure renewables have their issues, but you can work on them too. By the time a Thorium reactor is working will it just be a very expensive white elephant?

EDIT: I note that the UK doesn't see it as a viable power source, in general, but I believe they think it may have some value in helping to burn up plutonium and other difficult waste - which I think, if true, would be a good thing.
 

Montero

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Renewables - the cost of supply maybe. But there are lots of issues with intermittent supply and no large-scale reliable storage other than the most traditional of renewables - large reservoirs supplying hydroelectric. The storage for renewables is still in its infancy.
As well as intermittent supply, wind turbines have a very variable supply as the power produced is in proportion to the wind speed cubed - so it is up and down as the wind blows. The national grid in the UK is designed to be load balancing - keeping supply and demand very close to each other, with all the safety cut-outs triggering if the supply and demand are more than a fraction apart. The National Grid spends money on tracking power usage and predicting demands so they can bring another power station online, or turn up the turbines on one already running. Wind power is part of the grid but has to have a spinning reserve - this is a gas turbine power station kept on idle - with the turbines running hot but not putting out electricity - so if the wind suddenly drops the power station can pick up the slack. You can't cold start a gas turbine. Having diesel standby plants also works - subsidies were brought in for places like hospitals which have back-up generators - to make these available to the National Grid. This then expanded so you now have people applying to build diesel standby plants - as in fields full of diesel generators - under all the renewable regulations.
There is the further point about the type of supply - heavy industry needs a really meaty supply which renewables do not generate. This includes glass manufacture (needed in solar panels) and steel and aluminium (needed for wind turbines). Not to mention the rare earth elements needed for electromagnets in the wind turbine and as parts of the solar PV are largely sourced in China where there is a horrendous level of pollution caused by the mining.
 

Foxbat

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I'm sure I read somewhere about storage experiments with renewables using some kind of sand alongside solar panels. The idea being that it's heated up during the day using excess power generated from the sun and then the stored heat energy is used to generate in the dark hours. Wouldn't work in the UK for obvious reasons:D but probably has some merit for hotter countries.
 

Venusian Broon

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#9
Like I said, renewables have their issues :D;)

But I think I would rather we developed reliable energy storage to capture intermittent renewables and develop the technology more, rather than produce thousands of new nuclear reactors, that perhaps might be cleaner than the old nuclear reactors, but will still be producing nuclear waste that we and our descendants (and whatever species develops from us, and then the species that evolves from them and then...:whistle:) will have to deal with.

But, having said that, I believe we do need some form of reliable, fast start up, power generator that can handle the base load - with the current electrical grid we have...and I'd rather that was nuclear rather than coal. Maybe gas. Just a smidgen to get us through into the future.
 

Venusian Broon

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I'm sure I read somewhere about storage experiments with renewables using some kind of sand alongside solar panels. The idea being that it's heated up during the day using excess power generated from the sun and then the stored heat energy is used to generate in the dark hours. Wouldn't work in the UK for obvious reasons:D but probably has some merit for hotter countries.
Yeah, there's hundreds of possible schemes to store energy. I've read of schemes of storing compress air in abandoned mines, which seems a bit crazy, but should work. I think there's enough so that you can pick and choose the correct solution for the local environment and needs.

It'll be interesting to see where the countries who have sizable renewable assets take them in terms of energy storage - places like Denmark and of course our very own Scotland (54% of energy generated was renewable in 2015)
 

Venusian Broon

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#12

Montero

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@ Venusian Broon - Scandanavia does have a lot of renewable assets, Norway in particular is (from memory) 70% hydroelectric. Denmark has a very high number of wind turbines. For a lot of years, they've been running an interconnected grid - so when there is a lot of wind Denmark sells electricity, when there is less or no wind (or too much - turbines are turned off for safety reasons in gales) then they buy in. But that has a very complex buying and selling scheme and bid prices behind it. Maybe they will prototype storage, but......

At a domestic level - and this is purely domestic - there is the Island of Eigg scheme. Eigg was never on the National Grid, all the houses had individual diesel generators with fuel imported from the mainland and the locals were fed up with that and the ongoing noise in an otherwise quiet place. They got a whacking great grant from the EU and put in a local grid system fed by turbines, solar panels, hydroelectric and with diesel back-up. It is very heavily rationed.
Eigg Electric
As in
"ENOUGH FOR EVERYONE

We can only use what we make. To ensure nobody goes short, each house has a maximum use limit at any one time of 5kW, each business 10kW.

5kW is enough for an electric kettle and washing machine, or fifty 100w light bulbs! Spreading our use throughout the day is easy, and OWL meters tell us how much we’re using moment by moment."

I think that kind of rationing both in total and at a time is a very good idea and we should spread it to the mainland - not forever increase supply, but control demand. However it is not exactly a vote winner in a population used to having lots.


And another thingy - combined heat and power boilers - generate electricity, use the waste heat. Used to be only biomass and fairly large scale - so good as providing electrical power in an industrial setting where a lot of hot water is needed. (Or have one at your local swimming pool.) A few years back domestic sized gas powered central heating boilers were produced which are CHP - so you could have electricity generated in your own house by your gas boiler.
 
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