The LFTR (Liquid Fluoride Thorium Reactor) is a much more promising technology. For starters it's already been done, decades ago at Oak Ridge. It only needs to be commercialized. Also it lacks the hard gamma problems inherent in fusion.

See energyfromthorium.com [slashdot.org]

NIF itself isn't really the answer, though. It's great for super-dense matter studies and gathering information of use for nuclear bomb detonations, but if the goal is sustainable fusion, NIF's approach is too expensive and inefficient. Rather, you need to go with a variant like HiPER [wikipedia.org]. NIF relies solely on a compression pulse. HiPER uses a compression pulse plus a heating pulse. This allows the compression pulse to be much smaller and easier to achieve.

They don't.

Next question?

It seems to be that the thermal energy produced is equal to the optical energy put in. Well, great, it's a milestone of sorts, but still massively far off actually producing energy. First and foremost, conversion of thermal to electrical is 33-40% efficient. Then you have to convert that to optical, an efficiency I do not know, but seems according to the Wiki page to be 1% (422MJ bank, 4MJ shot, could be old). Still, maybe it could be a lot better, but probably wouldn't exceed 80-90%. So, you actually have to beat this "break even" by a factor of at least 3 in order to actually output energy. But that doesn't account for fuel production, nor maintenance or construction of the facility.

And, I should also point out that this story is just that their laser works, not that an sample was fired producing "break even" energy.

Will it work? Maybe. But realistically, by the time we see commercial power from this, a fission plant built today would be reaching end-of-life.

i thought you were serious until you mentioned the charlatan Rossi. Go kill yourself.

Not just Thorium, and there's probably better designs out by now anyway, but I for one was very pissed and still am that Clinton canceled America's Integral Fast Reactor project. Because ohhh scary nuclear. Except the IFRs produce less waste, safer waste, and can be fed just about anything, including most the crap that right now is considered waste.

Bad project, Bill kill!

I love how projected "breakeven" and "ignition" in 2012 has suddenly been extrapolated to MW powerplants on the grid within a decade.

Nevermind that we don't capture the energy yet, which might give us best-case 50% efficiency. Nevermind we need 3x breakeven the breakeven energy for converting heat into steam to power a turbine. Nevermind just about every factor of 2-3 efficiency loss out there. I'm going to post one goddamn link that was true when I interned there, and is still consistent today and then I want to see what the "scientists" who projected this commercial powerplant planned to do about this minor detail:

http://www.ieer.org/reports/fusion/chap3.html [ieer.org]

99% efficiency loss right off the bat. What's left for these people to even argue about?

You do realize that EXISTING thorium reactor designs -

1. Do not need water as coolant (hence no high pressure evironment and much smaller)
2. As designed will shutdown on their own with no outside intervention.
3. As designed they can't "overheat".

"Best results occur with molten salt reactors (MSRs), such as ORNL's liquid fluoride thorium reactor (LFTR), which have built-in negative-feedback reaction rates due to salt expansion and thus reactor throttling via load. This is a great safety advantage, since no emergency cooling system is needed, which is both expensive and adds thermal inefficiency. In fact, an MSR was chosen as the base design for the 1960s DoD nuclear aircraft largely because of its great safety advantages, even under aircraft maneuvering. In the basic design, an MSR generates heat at higher temperatures, continuously, and without refuelling shutdowns, so it can provide hot air to a more efficient (Brayton Cycle) turbine. An MSR run this way is about 30% better in thermal efficiency than common thermal plants, whether combustive or traditional solid-fuelled nuclear.[27]"

http://en.wikipedia.org/wiki/Thorium#Commercial_nuclear_power_station [wikipedia.org]

4. The US has a metric fuckton of thorium in it's coal deposits.

1. The definition of "ignition" here means laser energy onto target vs. fusion power out. Current laser technology is not efficient enough at the high powers needed for ICF. It's still meaningful because in laser fusion the target physics is largely separated from the lasers so once the principles work an improved laser can be developed.
2. The glass lasers used in NIF need to cool down for several hours between firings, whereas in a power plant the lasers need to fire at 10-15 Hz. High-power solid state lasers need development.
3. The indirect drive scheme used in NIF is too inefficient to be used in a power plant. NIF uses a hohlraum [wikipedia.org] to create a uniform implosion, but the conversion of laser energy to x-rays on the target is only a few percent.

I've been around NIF and it is an amazing machine. It's also designed (and funded) to study warm dense matter physics like equations of state at high density for nukes, not fusion. Use of NIF for fusion is a great side-benefit and hopefully they can get useful data from it.

The HiPER project to design a fusion reactor based on fast ignition has been though an initial concept design phase, but is now waiting further development. There is still a lot of research which needs to be done in target physics, lasers, and materials before ICF is ready to build an ITER-like machine

The physics behind the ITER tokamak [wikipedia.org] on the other hand is quite well understood at this point. Sure there are outstanding issues which are still being worked on (ELMS, divertor detachment, RWM control spring to mind) but we're pretty confident it will work. The design of ITER started in 88, and before that the INTOR project in '78, but it has taken a long time for politicians actually put some serious resources behind it. Hopefully it won't take that long for ICF projects like HiPER to be taken seriously and funded at a level which will make them happen

You can't make any industry completely safe. Nuclear power is probably one of the safest, but also so tightly controlled that when something bad does happen is is big news. Much like the crashing of a plane is big news compared to the crashing of a car - this doesn't make planes bad, they are in fact very safe compared to cars.

As an example, coal power has a history of serious disasters - from mining accidents (usually restricted to killing/injuring the miners themselves, but occasionally a big deal for the whole community around a mine [wikipedia.org]), to huge environmental disasters [wikipedia.org]. Even in normal operation, coal power plants are designed to pump toxic and radioactive material directly into the atmosphere.

The difference between the environmental impact of coal and nuclear is largely that the design of nuclear reactors largely keeps harmful biproducts carefully contained whilst coal doesn't. This means that it is considered a big deal when radioactive material contaminates the environment, whereas contamination from coal fired power stations goes unreported (since it happens routinely every hour of every day).

Another example: hydroelectric has the potential for really serious disaster [wikipedia.org].

To date, we have had just 3 serious nuclear incidents:
- Chernobyl was the big one, 4,056 people lost their lives. Whilest this is a large number, it pales in comparison to other disasters, such as the afore mentioned hydroelectric dam failure that cost 171,000 lives.
- Three Mile Island is often cited by the anti-nuke brigade, but that demonstrates an inability to read and understand the reports - three mile island is a pretty good example of everything going to hell and basically not much bad happening.
- Fukushima - a serious accident, of course. Low level contamination over a large area. But that's what it is - low level. The fact that the media concentrated on this nuclear power accident instead of the vast number of lives lost through the quake and tsunami demonstrates that nuclear power's big problem is down to image, hype and public paranoia/misunderstanding rather than a substantial level of risk.

Military reactors have a lot to answer for, of course. For example, Dounreay is a pretty good example of how not to run a nuclear facility. This is largely down to the fact that the military pretty much had a free reign to do what they liked rather than being under the strict regulation and oversight that commercial reactors are subjected to.

Stepping away from power and comparing to other large industries, I would much rather live next door to a nuclear power station than a chemical plant. In part because the nuclear power station will be subjected to much stricter regulation, but also because anything that does leak from the power station is likely to be much less of a danger than some of the really nasty substances used in chemical works (even though a nuclear leak will probably draw far more media coverage and protests from the environmentalists than a chemical leak would).

Fission really is one of the safest (if not the safest) method of large scale power generation. As for handling the waste: this can largely be reprocessed, we just need to provide incentives to do this rather than just storing it away. However, it seems unfair to compare the problem of handling nuclear waste with technologies that routinely release their wa

How do you generate hydrogen in a molten salt reactor? What's the source?

The Fukushima reactors generated it because the water was boiling to steam and reacting with the zirconium-cladded fuel canisters. There are no such canisters in a molten salt reactor, and there is also no water and no pressurisation of the containment structure (what's the vapour pressure of Lithium Fluoride anyway? ;) ).

The danger of overheating is also removed - the fuel is already molten *by design*, and is contained in the system by a plug of solid fuel that is kept below the melting point by active cooling. Should the power fail (or the temperature of the fuel go too high for the cooling if the plug to cope), the plug of fuel melts and the whole primary loop drains off and settles in a non-critical arrangement run off area. It will then either solidify, or remain as a liquid if the temperature is high.

Unfortunately Thorium is naturally found in a highly insoluble state so does not concentrate well into ore seams as does Uranium; instead Thorium generally finds itself dispersed as sands. Extracting the Thorium requires extensive mining and intensive processing, producing byproducts worse than Uranium mining. Processing Thorium ore into more useful fuel pellets for HWR or graphite moderated adjustable piles is only marginally better (energy, pollution, cost of plant) than processing Uranium into SEU, even though Thorium does not require enrichment (i.e., the processes are based on chemistry rather than isotopes). Thorium forms awkward compounds in chemical slurries - daughter products in LFTR were chemically hazardous, an explosion and corrosion risk, radioactive and had a tendency to decay into even more awkward compounds during cooling (not what you want in a SCRAM).

The primary reason BARC explored the Thorium fuel cycle so thoroughly was that India is very poor in known Uranium deposits, but has an enormous amount of Thorium sands domestically. Before rapprochement with nonproliferation politics, Thorium was its only bet without compromising its particular political neutrality with respect to the declared nuclear weapons states; its access to Uranium was almost certainly entirely reserved for weapons development. Things have changed now, and the Thorium fuel cycle is looking less attractive for several reasons. Cost of fuel is high on that list, since there is now an abundance of SEU to HEU available to it through trade. Consequently, BARC's optimistic projections of large numbers of Thorium fuel cycle civil power generation plants look far too aggressive.

That said, they or the South Koreans might buy AECL and integrate its civil power knowledge, patents, and processes surrounding e.g. CANFLEX, in which case mixed-fuel-cycle HWRs seem almost practical, depending on the capital costs and financing compared to buying an EPR or equivalent. Modern very high burn-up LWRs are more attractive for power generation than modern HWRs for a variety of reasons (cost of moderator, higher thermal output, neutron economy has been getting better in modern LWRs, and so forth).

Meanwhile the most likely use for Thorium fuel cycles is in chained or stacked fast breeders researching the production of higher thermal power and the breeding of weaponizable isotopes. Safety is less of a concern with that particular goal in mind, so molten slurry cores, high temperature highly chemically active coolants, and so forth are more likely to find use (as at ORNL).