Nonlinear adaptive coordinated control for high temperature gas-cooled nuclear steam supplying systems

Small modular reactors (SMRs) are those nuclear fission reactor whose electric output is no more than 300MWe. Due to its simpler, standardized and safer modular design, the SMRs can be factorily built, require smaller initial capital investment, and have shorter construction period. Modular high temperature gas-cooled reactor is a typical SMR with inherent safety feature. Based on the multi-modular scheme, the inherent safety feature is applicable to large-scale nuclear plants at any desired power rating. The MHTGR-based nuclear steam supply system (NSSS) is mainly constituted by an MHTGR, a primary helium blower and a once-through steam generator (OTSG). Due to the side-by-side arrangement for the MHTGR and OTSG, there is tight coupling effect, which leads to the necessity in studying coordinated control for the MHTGR-based NSSSs. In this paper, a new nonlinear adaptive coordinated controller is proposed for the MHTGR-based NSSSs, which regulates the nuclear power, helium temperature and steam temperature through adjusting the control rod speed, helium flowrate and feedwater flowrate. Sufficient conditions for the globally input-to-state stability (ISS) is given. Simulation results show the satisfactory performance of this newly-built coordinated NSSS control law.