Transport of nuclear heat by means of chemical energy (nuclear long-distance energy)

Abstract

Nuclear long-distance energy, i.e. the transportation of chemically bound energy, represents a potential application for process heat plants in which the endothermic reaction takes place at the heat source (high temperature reactor) whereas the exothermic back reaction occurs at the region of heat utilization (consumer). Due to the following criteria, i.e. reversibility of the chemical reaction, sufficiently large reaction enthalpy, favourable temperature region for the forward and back reactions, and the available technology, a combination of the methods of endothermic steam reforming of methane and exothermic methanation is chosen. As well as supplying household and industrial consumers with heating, process steam and electrical energy, an interconnected system with synthesis gas consumers (e.g. methanol production and iron ore reduction plants) is possible. It is shown that the amount of reactor heat which is convertible into long-distance energy depends considerably on the helium temperatures in the high temperature reactor and lies between 60 and 73% of the reactor power. Conceivable circuit schemes for the nuclear steam-reforming plants and the methanation plants are described. Finally, it is demonstrated, with the help of a simple model for cost estimations, that the nuclear long-distance energy system can make heating for households available in competition with oil heating and that due to the lower specific transport costs, for distances larger than 50 km it is also more economical than the hot water supply from the thermal power coupling of steam turbine plants using light water reactors (LWRs) or high temperature reactors (HTRs).