Potential use of molten salts bearing plutonium fluorides in a magnetic fusion energy reactor

This study presents the influence of addition of plutonium fluorides with different grades and compositions to Li2BeF4 (Flibe) on the neutronic performance of a magnetic fusion reactor called APEX that uses a liquid wall between the plasma and the first wall. Computations were carried out with respect to the liquid wall thickness with the help of the code Scale4.3 by solving the Boltzmann neutron transport equation. Numerical results brought out that a liquid wall of 37 cm in thickness would be required to make the first wall a lifetime structure with sufficient tritium production for the coolants using Flibe with either 0.5% or 1% of weapon grade PuF4, and a thickness of 34 cm would be required using Flibe with either 0.5% or 1% of spent fuel grade PuF4. In addition, these coolants improved the neutronic performance of the reactor by amplifying the fusion power remarkably. Moreover, the plutonium content (0.5% or 1%) in the investigated salts had no effect on the required blanket thickness since the helium generation was obtained as the life-limiting factor that was not affected by the plutonium content practically.