Patent #1 : Double Cylinders Molten Salt Nuclear Reactor - DCMSR
The original Oak Ridge experiment ran directly on uranium235 and uranium233 fuel. The GenIV proposal and the French/EURATOM SUMO reactors are designed for a full thorium cycle ie including the breeding stage where thorium232 is transformed to uranium233.
The optimal thorium MSR would be, for a number of reasons, so-called two-fluid ie with breeding and fissioning in physically separate but neutronically coupled salt loops. Oak Ridge struggled to build this optimal reactor but run into the so-called plumber problem : The sphere-centered nest of graphite channels would not simultaneously provide neutron economy and long-term structural integrity. The GenIV proposal is therefore one-fluid. The SUMO seems to be two-fluid but has a number of questions unanswered.
So our Patent # 1 solves the plumber problem in a surprisingly simple way : Concentric cylinders separate the flows !
Calculations leave ample design space to accomodate uncertainties in neutron spectras, barrier thickness and fluoride solubilities to be settled by straightforward R&D. The barrier material of choice would be a special hastelloy but the patent covers all barrier designs including graphite. And the neutron flux is confined by the thick thorium blanket. All kinds of fuels, fuel refilling schedules and waste processing schemes are covered. The first criticism of the DCMSR is that leaks between the loops could create supercriticality. We say that higher pressure in the blanket loop would stop uranium fuel entering the thorium blanket. Also a leakage is easily detectable. Multiple safeguards would be present ie gravitational core evacuation into dump tanks and poison injection shutdown.
Read David's publication on the DCMSR
The US Nuclear Regulatory Commission invited proposals on new and inherently safe reactors to ease
the licensing process. The DCMSR fits the bill perfectly and was accepted for preliminary review.