HIGH EFFICIENCY GENERATION OF HYDROGEN FUELS USING THERMOCHEMICAL CYCLES AND NUCLEAR POWER

The purpose of this work is to determine the potential for efficient, cost-effective, large-scale production of hydrogen utilizing high temperature heat from an advanced nuclear power station in a thermochemical water-splitting cycle. We carried out a detailed literature search of all published thermochemical cycles, creating a searchable database with more than 100 cycles and 800 references. We developed screening criteria and did detailed evaluation to select two cycles that appear most promising, the Adiabatic UT-3 cycle and the Sulfur-Iodine cycle. We selected the Sulfur-Iodine cycle for further development. We then conducted a broad-based assessment of the suitability of various nuclear reactor types to the production of hydrogen from water using the Sulfur-Iodine cycle. A basic requirement is the ability to deliver heat to the process interface heat exchanger at temperatures up to 900 °C. We developed a set of requirements and criteria, considering design, safety, operational, economic and development issues. We identified the gas-cooled reactor, the heavy liquid metal-cooled reactor and the molten salt-cooled reactor as suitable for coupling to the S-I cycle, selecting the helium gas-cooled reactor for our design. In the third phase of this work, we are generating an integrated flowsheet describing a thermochemical hydrogen production plant powered by a high-temperature helium gas-cooled nuclear reactor. This will allow us to calculate the hydrogen production efficiency and capital cost and to estimate the cost of the hydrogen produced as a function of the nuclear plant cost.