Autonomous Control Strategies for VHTR-Based Systems for Hydrogen Production

This paper is focused on feasible autonomous control strategies for Generation IV Very High Temperature Reactors (VHTR)-based systems for hydrogen production. Various burnable poison distributions and fuel compositions are considered. In particular, utilization of TRUs in VHTRs is explored as the core self-stabilization approach. Both direct cycle and indirect cycle energy conversion approaches are discussed. It is assumed that small-scale VHTRs may be considered for international deployment as grid-appropriate variable-scale self-contained systems addressing emerging demands for hydrogen. A Monte Carlo-deterministic analysis methodology has been implemented for coupled design studies of VHTRs with TRUs using the ORNL SCALE 5.1 code system. The developed modeling approach provides an exact-geometry 3D representation of the VHTR core details properly capturing VHTR physics. The discussed studies are being performed within the scope of the U.S. DOE NERI project on utilization of higher actinides (TRUs and partitioned MAs) as a fuel component for extended-life VHTR configurations.