Nuclear Reactors - Generalities 2. Nuclear Reactors Systems Review - Resources and Regeneration - Economy

After examining in the previous article the structure of nuclear reactors and their fuel, the strong coupling between reactors and the fuel cycle, the prospect of regenerating fissile nuclei, as well as the main constraints facing fission-based nuclear power, this article focuses on nuclear technology pathways and the topics dominating current events and the near future. It includes:

• a brief overview: proven technologies, technologies that have been demonstrated but not yet deployed, and technologies currently under study; the SMR path; cross-cutting advancements applicable across all technologies;

• an analysis of fissile nucleus regeneration, which enables a shift from conserving the scarce resource of the single ²³⁵ U isotope to conserving the totality of uranium and thorium elements; a discussion of the consequences of the autocatalytic renewal of fissile nuclei, which radically alters the orders of magnitude in the expected lifespan of fission energy;

• an examination of the relationship between the core spectrum and the constraints imposed on the neutron budget by regeneration, based on values of the key parameter η as a function of the fissile isotope under consideration and the incident neutron energy;

• a review of the main economic assessments of nuclear power generation, from the early days of nuclear power to projections through 2050; the move toward a comprehensive assessment of energy mixes: intermittency and its cost; an examination of the issue of plutonium’s value;

• finally, for the designer, in a changing nuclear landscape, the perilous constraint/opportunity: “new context, new initial specifications.”

This article will be followed by a third article addressing simplified modeling dedicated to the strategic analysis of design options, the role of radical innovation, and energy systems within the nuclear energy continuum combining fission, fusion, and accelerated charged particles.