thermal-hydraulic and neutronic design for a super critical water reactor using nanofluid as coolant

The most important intrinsic limitation of conventional coolant fluids is their relatively low thermal conductivity. in this regard, in the last two decades, by introducing a new concept called nanofluid, researchers have improved the thermal conductivity of conventional coolants; furthermore, thermal efficiency, as well as convection heat transfer of the thermal-hydraulic cycles, is increased by applying coolants at supercritical pressures. a supercritical water reactor is one of the generation iv reactors, which is a creative mixture of conventional pressurized water reactors and supercritical pressure steam boilers. in the present study, by applying the concept of nanofluid coolants in a typical supercritical pressure water reactor, the thermo-neutronic behavior of the reactor core was investigated. in this manner, thermodynamic properties of the applied coolant were evaluated by adding numerical models of nanofluid properties to the iapws-if97, and for simulation of the thermal-hydraulic behavior of the coolant, a modular computer code has been developed using the c# programming language based on the porous media approach, and neutronic simulation was performed by the mcnp code. final results showed that application of a water-based al2o3 nanofluid with ~11% mass fraction (~2% volume fraction at the core inlet) as coolant without any violation of neutronic characteristics of the core is achievable and the criticality of the core would be sustained. calculations indicate that applying nanofluids to the core will flatten the radial neutron flux in the reactor core, and the convection heat transfer coefficient will improve by 2%.