I wish they would be more up-front about the specifics of their technical proposal and how it compares to other proposals, since it was not at all obvious to me at first glance.
What I think they're actually proposing (correct me if I'm wrong): a uranium molten salt fast breeder reactor that drives a steam turbine. So, much more ambitious than what's currently on the market, with better fuel utilization. As compared to, say, the Flibe Energy/Kirk Sorensen/LFTR crowd, it's mixed: it sounds like these folks have some new innovations around moderators and salts, and the stuff about consuming existing waste is compelling, but they're sticking with a uranium fuel cycle rather than thorium (though it sounds like they're getting proliferation resistance in other ways), and they're sticking with a steam turbine vs. proposed gas turbines that could yield some more efficiency and compactness in proposed thorium MSR designs.
EDIT: looks like I might have been wrong about the neutron temperature; their white paper says thermal, not fast.
EDIT 2: the white paper actually has all kinds of great stuff in it, now that I've read the rest: http://www.transatomicpower.com/wp-content/uploads/2015/04/t... ... In particular, it sounds like this is the first planned design, but they offer some potential future variations. They say this design could be adapted to Thorium fairly straightforwardly, but advocate uranium at least initially because of advantages in the existence of a supply chain around it and the availability of uranium spent nuclear fuel. They also mention Brayton cycle gas turbines as a possible future improvement, among others.
To get this straight, when they indicate 96% utilization of the uranium, they don't mean converting 96% of the total energy to electricity, as it is assumed that some will be lost along the way, right?
If the above statement is true, what happens to the remaining 4% of the energy in the uranium? Is it just not effective to have it in the molten salt, so the entire batch is replaced? Or does this happen 'on the fly' so to speak?
It means 96% of the uranium fuel undergoes fission (gets its nuclear potential energy converted to heat). When they separate out fission products (waste) by chemical processing, about 4% of the fuel gets dragged into the waste stream. It looks like a cost/benefit decision not to recover it:
Of the 200 kilogram lanthanide mass removed by liquid metal
extraction, we estimate that approximately 20 kilograms will
be actinide contaminant with a longer half-life similar to
SNF. It may be most practical to leave such a small quantity
embedded in the ceramic granules, as it would be well
distributed and would not materially extend the time for the
overall waste form to reach background levels. If desired,
however, the actinides can be further separated offsite with
additional post-processing techniques.
I think it means that they'll be using up 96% of the uranium but the 4% is unusable with this method. That the concentration is down low enough that they're unable to extract energy from it at that point.
96% of fissile material converted to non-fissile material, and that energy is then converted to electricity at normal steam turbine efficiency, 30% or something. This as opposed to less than 1% for Gen III reactors.
Edit: I posted that fuel handling is a batch process, not continuous – that might not be true for molten salt, not sure.
What I think they're actually proposing (correct me if I'm wrong): a uranium molten salt fast breeder reactor that drives a steam turbine. So, much more ambitious than what's currently on the market, with better fuel utilization. As compared to, say, the Flibe Energy/Kirk Sorensen/LFTR crowd, it's mixed: it sounds like these folks have some new innovations around moderators and salts, and the stuff about consuming existing waste is compelling, but they're sticking with a uranium fuel cycle rather than thorium (though it sounds like they're getting proliferation resistance in other ways), and they're sticking with a steam turbine vs. proposed gas turbines that could yield some more efficiency and compactness in proposed thorium MSR designs.
EDIT: looks like I might have been wrong about the neutron temperature; their white paper says thermal, not fast.
EDIT 2: the white paper actually has all kinds of great stuff in it, now that I've read the rest: http://www.transatomicpower.com/wp-content/uploads/2015/04/t... ... In particular, it sounds like this is the first planned design, but they offer some potential future variations. They say this design could be adapted to Thorium fairly straightforwardly, but advocate uranium at least initially because of advantages in the existence of a supply chain around it and the availability of uranium spent nuclear fuel. They also mention Brayton cycle gas turbines as a possible future improvement, among others.