Fusion power could arrive sooner than expected

Clean, yes.

By any measure, cleaner than what else is out there. Already a fission nuclear power plant will produce less leakage of radioactivity into the environment than many coal plants, fusion drops that level several orders of magnitude more.

First off, no fission products, which are typically the most dangerous radioactive waste from fission reactors. Second, the materials used in the reactors don't have the same engineering constraints that fission reactors do and so can be chosen to produce far lower quantities of hazardous radioactive isotopes bred from intense neutron flux bombardment. Also, Tritium is a fuel, and of enormous value so it would be handled very carefully. More so, it would be bred specifically in custom built containment vessels within the reactor.

On top of all that you have the fact that a fusion reactor cannot be made to undergo a meltdown or overload the way a fission reactor can. If something bad happens in a fusion reactor the immediate result is usually that fusion stops, which compares very favorably to the what happens in a fission reactor: fission chain reactions continue, temperatures build as the heat from fission products decaying builds up, etc. And you don't have weapon proliferation concerns.

Overall what you have with nuclear fusion reactors is no chance of a meltdown, very much less hazardous waste generated (by orders of magnitude) and a very clean energy profile.

1. Who said it was 10 years out? I've never heard that. Sometimes milestones are 10 years out and the public tends to confuse milestones with the finished product.

2. Ideas for parallel implementations of nuclear fusion have expanded, and as a result, funding and research has arguably become fragmented and resources have been diverted. In reality, there's a fixed amount of capital and knowledge (which is also a function of the availability of money) available for this kind of research. The amount of money the US puts into fusion research is quite paltry compared to the potential benefits. It may be a priority, but the way Washington spends money says otherwise.

Scientifically, fusion is maybe 10 years away. Politically, it's more like 40 for a real power plant, but with the current congress, I couldn't say. In addition to that, it's an expensive enough endeavor that it would be corporate suicide for a private company to attempt it, especially considering the majority of companies with enough capital to pursue something like fusion tend to be in the Oil and Gas industries.

In fusion-based nuclear weapons, a fission bomb is used to create the temperature and pressure needed to kick off nuclear fusion. Calling that "combined fusion/fission" is like calling my car an electric hybrid because it uses an electric starter.

Detonating a nuclear weapon inside of a power plant isn't really practical. :-) Existing nuclear power plants don't get anywhere near the temperature and pressure needed to start nuclear fusion.

So, now we have the engineers trying all sorts of ways to get to the needed temperature and pressure without turning the plant into a smoking crater. That's where all the fancy lasers and magnetic pulses described in the article come in: They're trying to aim the heat source so they can superheat the fuel without melting the containment vessel.

I wouldn't mind a small amount of the money that goes into fusion research heading to liquid fluoride thorium reactors instead: http://en.wikipedia.org/wiki/Liquid_fluoride_thorium_reactor

Amongst the many attractive properties of LFTRs is the ability to burn spent fuel from existing nuclear plants.

That's a popular misconception, IIRC. Actually, in thermonuclear weapon the bulk of energy comes from fission. [1] Fusion is technically only used to get the high energy neutrons to get the bulk of fissionable material to undergo fission. So, ironically, calling it a "fusion bomb" is very much like calling your car an electric hybrid.

1. http://en.wikipedia.org/wiki/Thermonuclear_weapon