Self-stability analysis of MHTGRs: A shifted-ectropy based approach

Because of the strong inherent safety, the modular high temperature gas-cooled nuclear reactor (MHTGR) has been seen as the chosen technology for the next generation of nuclear power plants (NPPs). Self-stability of a nuclear reactor, which is the ability that the reactor state can converge to an equilibrium point without control input, has great meaning in designing control and operation strategies for the NPPs based on MHTGR technology. In this paper, self-stability of the MHTGR is analyzed from a physical viewpoint. A shifted-ectropy method for analyzing the stability of the equilibriums of general thermodynamic systems is firstly established. Based upon this approach, it is proved theoretically that the equilibriums of the MHTGR dynamics are globally asymptotically stable. Numerical simulation results, which illustrate the MHTGR self-stability feature directly, are consistent with the theoretical result.