A comparative study on production of thermal neutron scattering data for H2O based on molecular dynamics simulations using various water models

Abstract

Since H2O is the predominant material utilized as both a moderator and coolant in nuclear reactor operations, accurately describing the neutron moderation process within the H2O is crucial for reactor design and analysis. This work investigates the production of thermal neutron scattering data for H2O using molecular dynamics (MD) simulations with various water models. Conventional thermal neutron scattering models, such as the GA(General Atomics) and IKE(Institut f & uuml;r Kernenergetik and Energiesysteme), have been widely used but have limitations in accurately describing the dynamic behaviors of water molecules. In contrast, the recently developed CAB model utilizes MD simulations to capture intricate molecular behaviors more accurately. In this work, both rigid (SPC, TIP4P/2005, TIP5P-E) and flexible (SPC/Fw, TIP4P/2005f) water models are employed in MD simulations to generate the thermal neutron scattering data. Among these, the TIP4P/2005f model is identified as most reasonable choice due to its best agreement with experimental data and its ability to capture intramolecular interactions. The performance of the produced data was validated through criticality benchmarks, which showed the results comparable to the ENDF/B-VIII.0 data.