I know that such an animal exists. My possibly faulty recollection is
that the Fort St. Varain (sp) power station reactor was a thorium fueled
pilot plant along these lines.
Bechtel Inc. was involved in some of the licensing engineering for it, so
might be a source of info. Sadly I've lost touch with the the engineer I
knew who used to work at that plant.
Kyle L. Webb Dept. of Physics + Astronomy
kwebb@astro.phys.unm.edu University of New Mexico