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

TLDR

The study aims to assess the feasibility of large‑scale, cost‑effective hydrogen production by coupling high‑temperature nuclear heat to a thermochemical water‑splitting cycle. The authors performed a comprehensive literature survey, screened over 100 cycles, selected the Sulfur‑Iodine cycle, evaluated compatible reactor types, chose a helium gas‑cooled reactor, and developed an integrated flowsheet for the plant. The integrated design allows calculation of hydrogen production efficiency and capital cost, enabling cost estimates as a function of nuclear plant cost.

Abstract

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.