Reactor thermal-hydraulics

Abstract Temperature and pressure of reactor fluids and solids are important variables in steady state and transient operation. Along with associated coefficients of reactivity, they determine the magnitude of reactivity feedbacks. Conservation of mass, energy, and momentum are the basis for thermal-hydraulics models. However, since pressure transients reach a new steady state so much faster in a transient than mass or energy, the differential equation for momentum is usually unnecessary. This chapter includes short descriptions of major heat transport systems in nuclear power reactors and approaches for their dynamic modeling.