Medium Term (5-15 Years)
Concepts for recycling IFE target and chamber materials need to be studied experimentally, possibly using only nonradioactive elements. Experiments would be done to benchmark accident analysis codes with materials and configurations typical of fusion power plant designs. Success would be experimental validation of safety models.
Long Term (>15 Years)
The long-term objective would be to begin development of the licensing case for an IFE demonstration plant.
The purpose of an IFE power plant is to produce useful energy in the form of electricity or high-temperature process heat, or chemical energy in the form of hydrogen. To do this, the power plant must convert the energetic products of fusion reactions—high-energy neutrons and charged particles—into the desired useful forms. To become a practical source of energy, IFE must produce and convert the fusion energy in a manner that is technically feasible, environmentally acceptable, and economically attractive compared to other long-term, sustainable sources of energy.
The high-energy neutrons and charged particles from the fusion reactions deposit their thermal energy on the walls of the reaction chamber and in the tritium-breeding blanket surrounding the chamber. Everything outside the chamber and blanket, excluding the laser or particle beam drivers or the pulsed power system, is considered the “balance of plant” (BOP). The BOP includes the systems for conversion of thermal energy to electricity, the buildings and structures for the power plant, and all the conventional services. While schemes have been proposed to convert some of the charged-particle energy directly into electricity by electrostatic or magnetohydrodynamic processes, first-generation IFE power plants will most likely utilize fairly conventional thermal power conversion systems to convert the energy contained in the hot coolant from the chamber wall and blanket into electricity. Similar “heat engine” thermal power conversion systems are widely used on nuclear fission power plants and on fossil-fired power plants around the world. The Rankine cycle, or steam cycle, and the Brayton cycle, or gas-turbine cycle, are widely used heat engines that appear well suited for application to the conversion of thermal energy from fusion into electricity. There appears to be little need for power conversion system development that would be unique to fusion or IFE, although IFE-specific BOP designs will need to be developed, and opportunities for innovation should always be welcome.