ABSTRACT
An event that results in operational deviation from the steady state, nominal conditions constitutes a transient. It is of prime importance in nuclear power plants that the established safety limits such as those for pressure, fuel rod performance and off-site dose criteria are respected following all transients including the design basis accidents. Evaluation of the trend of plant parameters to ensure the safety limits are not violated requires the solution of neutron physics equations that govern power production and transport equations that govern thermal hydraulic aspects of systems and components, including fuel pellet, fuel rod, core and containment. The analysis of PWRs also includes the pressurizer, the reactor primary system and the steam generator secondary side. This chapter discusses the fundamentals of transient simulation and the related mathematical models for thermal hydraulic analysis of nuclear power plants. It demonstrates the evolution of these models throughout the years with respect to their complexity to an extent that the neutronics and thermal hydraulic feedback and the interaction between all of the plant systems are now integrated into one computational tool, whose analysis capability may also include certain aspects of the beyond design basis events.Fundamentals of Reactor Transient Simulation
