We certainly do (have 2000+ MW power stations) - though none under construction right now, and of course they always comprise several power generation units -- like for example a dozen or more hydro turbines at a dam in James Bay. The Darlington Nuclear Power station on Lake Ontario operates four CANDU 9 reactors, for a total of 3,524 MWe. The Nanticoke coal power plant, also in Ontario, has a capacity of 3,800 MWe. There are others.

The p-B11 reaction is attractive since the product is 3 alpha particles - no neutrons - so no activation of structure.

It would be feasible only if it produces net energy.

The downside of this reaction is the relatively high Z (as fusion fuels go) of boron (Z=5).  The energy losses due to ionization, recombination, brehmsstrahlung and cyclotron radiation make magnetic confinement very challenging.

If highly efficient proton beam sources can be developed and a direct energy conversion system be devised then there might be a chance of a feasible system.

Regarding your question, "What do you think? Think it could be doable?"

....I would say its "doable" to roughly the same extent as Bubble Fusion -- an interesting curiosity, which can certainly produces fusion reactions, but not on a scale to be useful.

Incidentally, I posted that Colliding Beam Fusion research link to the old NS board some time ago (I believe I mentioned the originator of the concept, Bohdan Maglich, and his "migma" trademark), but its obvious that there has been no progress in the field recently, since the web site has remained unchanged over many years -- I was quite surprised to even find that it still exists !

I guess the salient (negative) feature of this fusion scheme is that the reaction products add nothing towards sustaining the thermonuclear reaction conditions directly. High power would therefore require very high CURRENT accelerators, gobbling up vast amounts of power, as you already alluded to. You end up with a huge amount of high-tech harware, for very little benefit (net energy output). Not the sort of thing that's likely to lead to economic power generation.

Magnetic confinement fusion is certainly the "glamour boy" of nuclear technology.

Personally, I'm not a fan. In fact I particularly despise the misleading way its being marketed around the world, by both media and (most) project scientists :  we are told that it operates on the same nuclear reaction as the Sun (which it doesn't), when in fact it operates on the reaction(s) typical in bombs (albeit in a very low density, slow & controlled fashion).

While this may seem like nitpicking, my view is that this deceptive advertising is what has created a perverse mentality and the essentially politically-induced situation whereby we must spend endless billions on ridiculously complex fusion machines which are unlikely to ever be economically competitive with other power production means -- when we could have had fusion power "the easy way" decades ago. Of course I'm refering to "contained fusion" (as opposed to "controlled fusion") using serial detonation of explosive devices in large, steel-lined underground cavities, filled with a thermal energy absorption medium such as FLiBe salt spray.

Anyway, it doesn't matter, since fission power can make fusion unnecessary for hundreds of thousands of years at least, if we recycle spent fuel and use breeder reactors and uranium disolved in seawater. All three have already been tried, despite the fact that at this time some of these technologies are rendered unnecessary and/or uneconomical by the availability of cheap, high-grade uranium ore deposits.

Regarding the size of magnetic confinement fusion reactors, I have never heard of 50,000 MW Tokamaks. ITER is supposed to be around 500 - 700MW(thermal), and I believe the "commercial" units envisioned today are to be in the 1,500 to 2,000 MWe (ie. roughly 4,000 to 5,000 MW thermal) -- about 10x the size of ITER and not all that much larger than today's largest PWRs.

Here's an interesting article on fusion :

30 July 04, NewScientist.com news service

Amidst a prolonged stalemate over where to build the world's largest nuclear fusion facility, the US is halting work on a homegrown fusion project. The decision caused concern among researchers at a fusion meeting earlier this week.

The US is pinning its hopes on ITER (International Thermonuclear Experimental Reactor), which aims to lay the groundwork for using nuclear fusion as an inexhaustible and clean energy source.

But the project has been stalled since December 2003 because its six members - the US, the European Union, China, Japan, South Korea, and Russia - cannot agree on where to build the facility. The EU, China, and Russia favour the French city of Cadarache, while the US, South Korea, and Japan back the Japanese town of Rokkashomura.

The deadlock has persisted even after both the EU and Japan sweetened their offers in June, each agreeing to pay half of ITER's estimated $5 billion construction costs to host the reactor. And rumours have spread that some parties might splinter off to build the reactor on their own.

No backup

Planning for FIRE was actually begun in 1998, when the US Congress directed the DOE to pull out of ITER. Since then about 50 researchers have been working on a "preconceptual" design for FIRE. But the approximately $2 million annual budget for this will come to an end in September.

In 2003, the US rejoined ITER, and now the DOE says FIRE will not serve as an alternative even if ITER falls through.

"We do not have a backup plan," Anne Davies, director of the DOE's Office of Fusion Energy Sciences, told New Scientist. "We are focused on making ITER work. If ITER doesn't work, we are going to have a lot of reassessing to do."

Davies said FIRE's use of copper magnets - instead of superconducting ones like ITER - was "dead-end" technology that would not lead as quickly to the goal of a fusion power plant.

She added that Congress would probably balk at building the $1 billion FIRE reactor without international partners, and that such partners might not want to sign onto a project whose plan was already so well established.

Square one

FIRE's design team leader Dale Meade, a physicist at the Princeton Plasma Physics Laboratory, agrees that ITER should take top priority.

But during public comments at a meeting of the DOE's fusion energy sciences advisory committee near Washington, DC, this week, he urged the government to reconsider its decision to scrap FIRE as a backup.

"I was reminding them we were ready if called upon," he told New Scientist. If ITER negotiations fail, he says, "we might have to take a step back, but we don't want to go all the way back to square one".

Earl Marmar, a physicist at the Massachusetts Institute of Technology who has reviewed the FIRE design, says it is a viable alternative to ITER. If FIRE were pursued, he says, it would be best to do it with international participation, but he says ITER has proven how difficult that can be.

"ITER has been technically ready to move forward for at least a couple of years - it's really been a political holdup," he told New Scientist. "We're all hopeful ITER will succeed, but we're also rather impatient."

Maggie McKee

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Regarding your question about "how much CO2 is emitted from mining and processing/refining steps," there is a nice article on energy lifecycle analysis (LCA) posted on the (recently launched) web site of Nuclear Engineering International magazine :

15 September 2004

Steve Kidd, Head of Strategy & Research at the World Nuclear Association

Even with gas diffusion enrichment, it is clear that the studies which attempt to show that there is little or no net energy gain from nuclear are absurd, relying on unrealistic assumptions about key elements of the fuel cycle. In fact, best estimates of the energy inputs in each area, backed up by a thorough study from Vattenfall of the Forsmark plant, show that the energy inputs in nuclear are at most only 5-10% of the output. Only hydropower can beat this, with both coal and gas lagging well behind.

Centrifuge enrichment, however, is very economical in energy terms and only uses about 2% of that consumed by a gas diffusion facility

nuclear incurs only about one tenth of the external costs of coal. This is because the waste costs of nuclear are already internalised, which has the effect of reducing the competitiveness of nuclear when only internal costs are considered, as in conventional financial analyses.

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.....of course Canada's CANDU reactors use natural uranium fuel, so there are no enrichment energy losses -- but we get barely a quarter of the burnup that PWRs do, so the mining & processing is a larger component in that case, plus there are losses in the production of heavy water for CANDUs. An assessment of CO2 emissions from CANDU including the nuclear fuel cycle and heavy water preparation is posted on the CNA website noted below. The assessment used data from actual mining operations of Cogema and Cameco. It also looked at the preparation of heavy water from the perspective of fossil fuel and nuclear steam as the energy source.

http://www.cna.ca/english/files/Climate%20Change/candureactors.pdf