Neutronics modeling and simulation of temperature-dependent experiments performed at the walthousen reactor critical facility (RCF) using proteus-SN

The Walthousen Reactor Critical Facility (RCF), owned and operated by Rensselaer Polytechnic Institute (RPI), is a low-power nuclear reactor for performing reactor physics critical experiments. Its open-pool capabilities allow for novel and unique experiments that would not be possible in other high-powered research reactors. As part of the effort to develop critical experiments_-to validate multiphysics coupling models in the SHARP toolkit, critical experiments need to be designed modeled and simulated by Proteus-SN, a finite element neutronics solver in SHARP based on discrete ordinates (SN) method. Proteus-SN requires unstructured mesh geometry to model nuclear reactors. In previous work, the RCF reactor has been modeled and simulated in MCNP6 and Serpent_2 based on constructive solid geometry. In current work, RCF pin cell and full-core models in 2D and 3D are constructed based on unstructured mesh geometry. Eigenvalue problems based on these models are simulated in Proteus-SN, using the cross-section data prepared by Serpent_2. Several critical experiments, including reactivity measurements at atmospheric pressure and at varying temperatures, are simulated by MCNP6, Serpent_2 and Proteus-SN. Results are compared with each other to verify Proteus-SN for the modeling and analysis of RCF. In addition, reactivity values predicted by Proteus-SN are compared against the RCF experimental values for model validation.