Thorium / LFTR Reactors - the cheaper and safer nuclear technology

[Madus_Maximus 0]

Gnat;2100974']Well' date=' I'd have to say Japan is a FAR from an ideal country to base ANY large plant in, nuke or otherwise, especially coastal.

- Very small size

- Very high population desity

- Earthquakes

- Typhoons

- Tsunamis

- Volcanos !

Not the best example.[/quote']

The problem is, nuclear is the ONLY (current) option available to them. There's no other way they can produce the amount of power their population needs to sustain itself without having total (or near enough) reliance on an outside party. They have sweet F.A. natural resources like gas, oil or coal, so those kind of plants are out of the window. Their cities are far too dense and land is far too scarce to use wind, their shores aren't all that great for wave power and their weather is far too varied for solar (not to mention the huge amount of land such plants require). They have very little in the way of large rivers they can dam for hydro power too. They're left with no other real alternative. I'm sure they've been looking for one for years, and now more than ever, but it's sadly not that easy.

[[aps]gnat 28]

Yes I know. Thats part the reason why Japanese companies are buying billion dollar Natural Gas contracts (via direct investment in field development) in my country ..... upcoming Gas Turbine power stations.

[Dwarden 1124]

again why we having this debate?

Fukushima power plant is one of oldest in japan, has 2 or 3 obsolete reactors

(these were supposed to be closed half year before the tsunami incident)

they obtained the usual one time +20 years (or was it 10 years) extension

but that was supposed to go hand in hand with massive modernization which

in this case not happened at all ... and that resulted into worst outcome ...

also imo i have specific theory about the one reactor there, as the type is used

to produce enriched output - which is usable for nuclear weaponry or similar ...

these factors combine and even hinders fast fix-up and result into big disaster a

but also into lesson learned and example how not do things

we would not move on secure modern nuclear plants or even develop low yield reactors

w/o CH, TMI, F etc. happen in first case

blindly deny advantages and stability of these power-sources over others is just naive

it's just absurd claim fosil fuels are safer while slowly polluting the world 24/7/365

if you let the development and advantages of last 50y research to shine You will easily

resolve and surpass anything we had built and use now

[glerner 1]

why not simply build the plants deep underground, away from subsurface water?

For current reactors (PWR, LWR): They are cooled by water, lots of it; need to bring water in, and send water out. Need to maintain and repair (for example, high pressure water requires fixing pipes often). Need to remove and replace spent fuel rods.

For LFTR: No high pressure coolant, no water at all. Refueling is either a) add liquid UF4 on a schedule or b) use a LFTR design that simply has fuel for 30 years and runs without reprocessing. So, Yes, bury it! However, the burying is to prevent simple car-bomb type terrorist attacks. The fuel and coolant don't dissolve in water, don't react with water, there's no high pressure to explode, (instead of complex engineered safety, there is a lot of inherent safety) and in a problem (for example earthquake), the liquid fuel can simply be drained to passive cooling tanks where nuclear reaction is impossible. The uranium and transuranic elements are strongly chemically bound to the salts, which cool to a glass-like solid. Cooling by passive air or water cooling towers above ground.

See LFTRs Do Not Need High Pressure Containment and No Water Needed for LFTRs, and no Loss of Coolant Accidents for more detail.

Edited February 5, 2012 by glerner

[glerner 1]

The question you have to ask, is what happens when somebody will make a mistake, will take the wrong decision (because of lazyness, lack of money, you name it)? What happens when some external, unexpected event happens? ... what happens when catastrophic events occur? When someone decides to cut costs and lower security? ... And it happens, for every energy source. There's no reason that it won't happen with nuclear power, absolutely no reason that miraculously, every cause of outage seen in every industry disappear in the nuclear industry. Catastrophic events will happen. Are the consequences worth it?

We know there will be failures. We know several failures that current reactors (PWR, LWR) have that are impossible in a LFTR: high pressure water explosions (no water, and atmospheric pressure), loss of coolant accidents (the liquid salts are minimum 500 degrees below the temperature they become gas, and the uranium and transuranic materials are all strongly chemically bound to the salt), hydrogen explosions (no hydrogen at all in most LFTR designs, minimal in some others, and no high pressure to contain it). Let's add the nuclear waste to the failures of PWR/LWR, that LFTR can't produce (and can even consume). I've gone into more detail what failures I think LFTRs could have, and what can be done to prevent those accidents (including terrorist attacks), at Passive and Inherent Safety and How Might LFTRs Fail?

Gnat;2100974']Well' date=' I'd have to say Japan is a FAR from an ideal country to base ANY large plant in, nuke or otherwise, especially coastal.

- Very small size

- Very high population density

- Earthquakes

- Typhoons

- Tsunamis

- Volcanos !

[/quote']

If you're talking about current PWR/LWR reactors, yes. If you're talking about LFTR, I'd say Japan is an excellent country for it -- for each of those reasons.

Instead of complex engineered safety, LFTRs have high inherent safety, plus passive safety:

LFTRs don't need water coolant, don't need water at all (you could heat transfer to a steam turbine, or a gas turbine to make electricity)

LFTRs operate at atmospheric pressure, since the coolant stays liquid up to ~1400 degrees C (reactor might be 700 to 1000 degrees)

LFTR coolant doesn't react to water (unlike a sodium cooled reactor, like the Japanese http://en.wikipedia.org/wiki/Monju_Nuclear_Power_Plant ) and doesn't dissolve in water;

LFTR fuels (uranium and transuranic elements) are strongly chemically bound to the coolant, which cools to glass-like solid

That means no loss of coolant accidents, no high pressure explosions, no hydrogen explosions, no radioactive materials released to the air.

That means no massive containment building (in a PWR/LWR, that is to contain water coolant becoming steam in an accident, LFTR doesn't have that), and no large buffer zone with low population is needed.

LFTR has no spent fuel rods, no spent fuel rod cooling ponds, no ponds leaking to the ground or ocean.

For 1 gigawatt-year of power, PWR/LWR take 250 tons of uranium, to make 35 tons of enriched uranium, and fission about 1% of it. 250 tons of waste for a million years.

For 1 gigawatt-year in a LFTR, need 800kg of uranium (whether from thorium or nuclear waste) or plutonium, any isotope. 99+% gets fissioned. Of the 1 ton of waste, most is completely safe in 10 years. 135kg (300lbs) needs to be stored for 350 years.

I think 135kg for 350 years is better than 250,000kg for thousands to millions of years, for a country with small area and high population density.

Site footprint: A uranium fueled light water reactor, or a seed-and-blanket solid fuel reactor would need 200,000 to 300,000 square feet, surrounded by a low-density population zone.

A LFTR would need 2,000 to 3,000 square feet, with no need for a buffer zone. Thor-Facts

Since a 200MW LFTR would fit in a tractor trailer, any LFTR near a volcano could be designed for "emergency release" and carried away by helicopter. (Go to my blog, I cover some design requirements). But even lava melting the reactor wouldn't release as much radiation as Fukushima (anyone know the temperature of lava?), because there isn't nearly as much uranium around as a PWR would have.

I go over how much waste, what's in the waste, how long until it's safe, how much Thorium or nuclear waste it consumes, (and how LFTR compares to current reactors with all of these) at No Long-Term Toxic Waste Storage.

I go over the inherent and passive safety features at LFTRs Do Not Need High Pressure Containment and No Water Needed for LFTRs, and no Loss of Coolant Accidents.

I've gone into what failures or accidents I think LFTRs could have, and what can be done to prevent those accidents (including terrorist attacks), at Passive and Inherent Safety and How Might LFTRs Fail?

I think LFTRs would be ideal for Japan.

Edited February 10, 2012 by glerner

[[aps]gnat 28]

Some movement .....

Westinghouse enters U.S.-China nuclear collaboration

"It's helping DOE-funded U.S. universities commercialize an alternative nuclear technology known as 'molten salt' in a project connected to country's partnership with the Chinese Academy of Sciences."

Another article

"While the US has only paid lip service to thorium in recent decades, China is joining the likes of India, Japan, and Norway in a quest to develop a working, commercially-viable thorium reactor."

While all empires eventually come to an end, the US will quicken its demise if it plays the wrong "energy" card .....

[instagoat 133]

Unfortunately it's nuclear, nuclear power is a demon, so we don't use nuclear power.

Thorium reactors were being developed alongside the original piles back in the 30s, but the concept was not taken up because they are not good at producing weapons grade material for nuclear weapons. Pretty much all current nuclear powerplants use reactors that are ultimately derived from a design that was not made to produce energy, but to produce waste that could be used to produce nukes.

I'd love to see this go somewhere, but I think the opposition would be too great, and until the renewable sources run out of overhead, this will not become an alternative. Scared as people are of nuclear powerplants, they'd much rather prefer coal or oil, I'd imagine.

I am much more interested in seeing fusion power develop, unfortunately that one has been proving one tricky bitch to crack. In the 50s they said the first operational fusion powerplants would become operational and supplying the net by 1990. Today they say that a functional fusion powerplant supplying the public network is at least another 50 - 70 years away. The prototype Tokamak in france will not become operational until 2030~, roundabout.

But at least this is better than these idiotic Ideas suggesting hydrogen energy cell based powerplants.

[Mattar_Tharkari 10]

While it does look promising it's more than a little over hyped:

The Guardian: Don't believe the spin on thorium being a greener nuclear option

http://www.theguardian.com/environment/2011/jun/23/thorium-nuclear-uranium

http://www.nnl.co.uk/media/27860/nnl__1314092891_thorium_cycle_position_paper.pdf

Onr thing I notice is overlooked in all the supporting evidence in this thread is that thorium isn't a fissile material (it's fertile), it needs to be converted to U²³³ first before fission can occur. So when it is described as an alternative to uranium it isn't really. The theoretical work on how to do that within a molten salt is there but the actual proven technology doesn't actually exist yet. In previous working examples the thorium had to be 'kick started' with a neutron source to create U²³³. Other sobering details are mentioned in the NNL paper such as: cost, complex reprocessing and it isn't waste free either, it produces less waste. Despite claims, it is possible to extract the U²³³ to make nuclear weapons so the non proliferation argument doesn't stack up either.

Edited January 17, 2014 by Mattar_Tharkari