GEM*STAR: The Alternative Reactor Technology Comprising Graphite, Molten Salt, and Accelerators

The technology of nuclear power could be quite different from today’s if it had been practical in the beginning to supplement fission neutrons with accelerator-produced neutrons. The purpose of this chapter is to illustrate the possible benefits of implementing supplementary neutrons from accelerators in an optimized reactor. GEM^∗STAR (Green Energy Multiplier^∗Subcritical Technology for Alternative Reactors developed by Accelerator Driven Neutron Applications (ADNA Corp) is a subcritical thermal-spectrum reactor operating with molten salt fuel in a graphite matrix and in a continuous flow mode initially at k_eff = 0. 99. The model described is able to use natural uranium as fuel and generate twice as much electric power as a light water reactor (LWR) generates from the same mined uranium. GEM^∗STAR at k_eff = 0. 99 also can be fueled with unreprocessed LWR spent fuel, and it can generate as much electricity as the LWR had generated from the same fuel. Because GEM^∗STAR uses liquid fuel, it can recycle its own fuel at k_eff = 0. 95 without any operations on the fuel. This recycle can be repeated several more times, always without reprocessing, as accelerator or fusion neutron generation technology development reduces the cost of neutrons. GEM^∗STAR therefore increases the electricity from mined uranium many times while avoiding the serious problems of current nuclear-power technology arising from enrichment, reprocessing, fast reactor deployment, and near term high-level waste storage. GEM^∗STAR also offers technology for nuclear energy generation that promises reductions in nuclear electricity cost and eliminates major proliferation concerns. The technology can use a modest source of intermittent “green” electricity such as wind or solar as input power to drive an accelerator that, in effect, multiplies the green energy by a factor of about 30 with 24–7 continuity and without compromising any environmental objectives of green energy sources. This chapter is not a complete history of molten salt, graphite, and accelerator technologies, but a description of how these orphan elements of nuclear power development may be integrated for a GEM^∗STAR solution to the main barriers that constrain the full deployment of today’s nuclear power technology.