Advancing production of hydrogen using nuclear cycles – integration of high temperature gas-cooled reactors (HTGR) with solid oxide electrolyzers (SOE)

Abstract

The work presented in the paper focuses on the investigation of coupling high-temperature gas-cooled nuclear reactor (HTGR) with solid oxide electrolyzers (SOE) for large-scale production of hydrogen. In the analysis, four cases related to loads of the nuclear reactor were under consideration. These included operation at the nominal load (100%), as well part-load operation (25, 50 and 80%).Paper presents the assessment of several alternative modes of operation of the HTGR-SOE hybrid. It can be concluded that under the given assumptions, electrical loading of the electrolyzer can be varied between 5 and 31 A (for 25% and 100% load of HTGR, respectively), and the corresponding voltage is in the range from 1.03 to 1.29 V. In terms of the size of the hydrogen production island, the electric power of the electrolysis was in the range from 12.42 to 96 MW, while the heat necessary to operate the SOE was provided by the steam cycle of the HTGR. The work provides qualitative and quantitative assessment of the possibility of generating hydrogen in a hybrid system which addresses the off-design operation of the nuclear reactor.