Self-consistent nuclear energy systems

Abstract

A concept of self-consistent nuclear energy system (SCNES) has been proposed as an ultimate goal of the nuclear energy system in the coming centuries. SCNES should realize a stable and unlimited energy supply without endangering the human race and the global environment. It is defined as a system that realizes at least the following four objectives simultaneously: 1. a) Energy generation — attain high efficiency in the utilization of fission energy, 2. b) Fuel production — secure inexhaustible energy source: breeding of fissile material with the breeding ratio greater than one and complete burning of tansuranium through recycling, 3. c) Burning of radionuclides — zero release of radionuclides from the system: complete burning of transuranium and elimination of radioactive fission products by neutron capture reactions through recycling, 4. d) System safety — achieve system safety both for the public and experts: eliminate criticality-related safety issues by using natural laws and simple logic. This paper describes the concept of SCNES and discusses the feasibility of the system. Both “neutron balance” and “energy balance” of the system are introduced as the necessary conditions to be satisfied at least by SCNES. Evaluations made so far indicate that both the neutron balance and the energy balance can be realized by fast reactors but not by thermal reactors. Concerning the system safety, two safety concepts: “self controllability” and “self-term inability” are introduced to eliminate the criticality-related safety issues in fast reactors.