India is active in the liquid-salt thorium reactor development venue. India has no uranium deposits, but it has a lot of thorium and since only a small amount of 'waste' from a conventional reactor is needed to seed a thorium reactor, this would greatly benefit their plan to bring power to all parts of their country.

I would like to take this opportunity to quibble with the term 'waste'. This is a good example of derisive labeling. "What are we going to do about all of this horrible nuclear waste?" people wail. It is not waste, it is byproducts; it is not something that needs to be gotten rid of but something that needs to be preserved as a resource. To whit: use in seeding the reaction in the next generation of reactors. To call it 'waste' is to fall smack dab into the agenda of people who are against nuclear power.

I would also like to mention that, back in the 60's, before the environmental movement shut down nuclear development, there was discussion as to whether, with nuclear plants as the source of electricity, it would cost more to bill for electricity than the effort would be worth. India may be the nursery of the thorium reactor but we would all like to have the benefit.

Jan

sounds similar to the breeder reactor of the Jimmy Carter era, the problem will be that the granola chomping nutbags that always file lawsuits and cause costs to rise to such a level that the projects die...are all a bunch of Luddites that want us all living in grass huts.

Molten Salt Reactors (MSRs) are a Generation IV reactor concept that has been around since the 1950s (like most concepts). It always has looked like the most promising concept for utilizing used nuclear fuel from light water reactors. There are several significant technical challenges. The biggest is the fact that it uses fluorine salts that the actinides and other heavy metal fuels are dissolved in. Fluorine is one of the most corrosive elements in the periodic table of elements.

Pumping a molten, heavy metal fluoride salt mixture through the reactor's primary loop and going through a heat exchanger to dump heat to the secondary loop (which uses either a Rankine or Brayton cycle to drive the electric generator) introduces a couple of big problems that nobody has wanted to tackle with much R&D spending:

1) Severe chemical corrosion of all components in the reactor's primary loop (pipes and the intermediate heat exchanger) is a big life-limiting and maintenance problem. In a Gen II (current) or III (being built) reactor (light water reactors), chemical corrosion of pipes from cooling water is the biggest maintenance challenge (significant cost) over the typically 60 year life of a nuclear power plant. Using fluoride salts makes all of these material compatibility and maintenance issues an order of magnitude more problematic.

2) Pumping a radioactive, molten fluoride salt mixture through the primary loop pipes and intermediate heat exchanger degrades their material properties faster (in addition to the corrosivity problem) due to radiation damage of the metal alloys in the structural material. This significantly shortens the useful life of the structural material, requiring more frequent replacement of pipes and intermediate heat exchanger (difficult inside the reactor's radiation containment...).

There are other less challenging problems with MSRs, but the 2 above are the ones that have been show-stoppers to any significant R&D investment over the years. There are 5 other Gen IV reactor concepts receiving most R&D funding, due to being less challenging, etc... Two of those also help close the nuclear fuel cycle (minimize waste) but are breeder reactors (a proliferation concern since the plutonium can be extracted for use in weapons) -- LFRs and SFRs:

1) Lead-cooled Fast Reactors (LFRs), being advanced by Russia in their BREST family of reactors, use more conventional solid nuclear fuel elements in the reactor core that mix in used nuclear fuel. The coolant is liquid lead instead of water. Molten lead has a high heat capacity, making it thermally a great coolant. However, lead has a high melting point. If the temperature of the lead drops too much, it starts solidifying inside all the pipes of the primary cooling loop (which usually have heaters to try to avoid this...).

2) Sodium-cooled Fast Reactors (SFRs) advanced mostly by the U.S. and a few other countries are similar to LFRs but use liquid sodium as primary coolant. Sodium has a significantly lower melting point than lead. The drawback is the risk of sodium fires, if hot sodium comes in contact with air (like if a pipe springs a leak at a joint). So, the reactor core has an inert atmosphere and inspections are more frequent for pipes, etc... The U.S. DOE successfully built and ran test SFRs (EBR-I and EBR-II) from the 1950s through 1994. While successful, they were expensive projects.

I think the likely long-term future combination for U.S. nuclear power plants will use a mix of 2 types -- VHTRs (commercial) and SFRs (DOE). For closing the nuclear fuel cycle, a DOE-operated SFR (with required adjacent used fuel reprocessing plant) would be dedicated to more fully utilizing spent nuclear fuel from commercial power plants. For commercial power plants, VHTRs (Very High Temperature, gas-cooled Reactors) would operate with higher efficiency than Gen II light water reactors. VHTRs, due to the higher temperature of the helium gas exiting the reactor core, can also be used as process heat for hydrogen production and other industrial facilities, in addition to electricity generation. R&D on VHTRs is much further along than most of the other 5 Gen IV reactor designs.

Of course, the biggest roadblock to innovation is the U.S. Nuclear Regulatory Commission (NRC, which is separate from the DOE). Any new reactor design takes at least 8 years (usually far more) to obtain NRC licensing approval for commercial construction and operation. The nuclear power industry is the most heavily regulated industry in America, which results in a depressingly slow pace of innovation...

There are always problems but the proof of concept is done. It ran for thousands of hours in Oak Ridge. Its time to build a power plant and work the production issues. From what I've read corrosion is not a major stumbling block.
It seems to me that if we wish to remain competitive in wold power generation it's time we turn loose the productivity and imagination of Americas industry.

what we need is an island on which to try a SFR,
recommended by robertmbeard, on this post, crossed
with a thorium reactor using set-aside (Not Waste)
fuel rod pellets, to prove it in. then, strong-arm the
NRC with evidence that it works. rotating blackouts
produced by BHO's curtailment of the coal-power
industry should get the public on our side.

if it were mine to design, I would have multiple
fuel flow paths, multiple coolant flow paths, and
multiple cooling tower flow paths -- to allow long
runs during alternate-pipe maintenance.
too expensive? how expensive are shutdowns?

just thinking ! -- j

It reminds me of the Pebble Bed Modular Reactor design from South Africa. For its forty-year span, you load it in advance with all the fuel it will ever need. And when its fuel is spent it is SPENT. You then pour concrete on top and bury the whole thing in place.

But the real goal--and let's not kid ourselves--is fusion.

I have read about reconstituting spent fuel before, but this sounds even better. Very intriguing. They predict the cost of nuclear produced energy would be cut in half. Cheap energy is a prerequisite for a growing economy.

There are new stainless alloys for MSR's about twenty five years ago Sweden created 904L stainless for such purposes. Your Nickel Alloys are even more expensive. I'm sure by now there are more formidable stainless alloys will work very well in such reactors. Exotic pipe coatings have a certain life expectancy. They are more prone to erosion by the molten salt flowing through the piping. Once you have the materials aspect of of building the nuclear worked out is the getting approval to build it and stop the Luddites from holding everything up with frivolous law suits.

Like all innovative ideas, it has to be tested and the glitches worked out. After testing it may or may not work. However, I doubt if the state will allow it to get off the ground. There are several reasons for this, not the least of which is that it goes against their desire to control the nations power. Their enemy is coal, and nuclear power in particular. I'm not a scientist or engineer by any means, but this is another opportunity for me t point out how we are sliding into another Dark Ages, where the controlling entities hate innovation and see it as a threat.

That the article did not mention the caustic reactions problem indicates to me this is money grab that will produce nothing. If an article is in Business Week I generally ignore it.

The irony is that the lefties are shutting down nuclear power plants with alarming frequency throughout the Northeast right now.

Other than the fact that this deals with radioactive waste vs. regular waste, this is the approach that my former company use to take, but that was before I went Galt......Sigh.

This is a more interesting approach that vitrifying nuclear waste (encasing it in glass), which is the traditional way.

Fascinating.