RELIABILITY AND SAFETY ASSESSMENT OF A CONCEPTUAL THERMOCHEMICAL PLANT FOR NUCLEAR-BASED HYDROGEN GENERATION

Hydrogen is a clean fuel that can help to reduce greenhouse gas emissions, as its oxidation does not emit carbon dioxide (a primary greenhouse gas). Generation of hydrogen has attracted much recent worldwide attention. A promising method to generate hydrogen is to use heat from nuclear power plants. The advantages of using nuclear heat are capabilities of large-scale generation of hydrogen and zero greenhouse gas emissions. Nuclear energy is expected to have an important role for hydrogen generation in the future. In this paper, reliability and probabilistic safety assessments of a conceptual nuclear-hydrogen plant will be analyzed. There are two main methods to generate hydrogen from nuclear energy. They include: 1) thermochemical processes and 2) electrochemical processes. The conceptual plant of this paper is based on a Cu-Cl thermocycle developed by Atomic Energy of Canada Limited (AECL) and the Argonne National Laboratory (ANL). Using a flowsheet of the hydrogen plant created by all Aspen Plus simulation by ANL, four fault-trees are constructed for potential risk scenarios. Based on the results from the fault tree analyses (FTA), the risk levels of the hydrogen generation plant under different accident scenarios can be calculated. Based on the results, potential problems encountered in Cu-Cl cycle are identified and possible solutions will be recommended for future improvements.