The sulfur-iodine cycle (S-I cycle) is a thermochemical cycle processes which generates hydrogen from water with an efficiency of approximately 50%. The sulfur and iodine used in the process are recovered and reused, and not consumed by the process. The cycle can be performed with any source of very high temperatures, approximately 950 °C, such as by Concentrating solar power systems (CSP) and is regarded as being well suited to the production of hydrogen by high-temperature nuclear reactors,IEA Energy Technology Essentials - Hydrogen Production & Distribution , April 2007 and as such, is being studied in the High-temperature engineering test reactor in Japan.https://smr.inl.gov/Document.ashx?path=DOCS%2FGCR-Int%2FNHDDELDER.pdf . Progress in Nuclear Energy
