Our group conducts basic and fundamental research in the fields of reactor physics and thermal hydraulics to improve the safety and performance of nuclear reactors.

In the field of reactor physics, we are improving various codes that calculate reactor-design parameters such as criticality and the amount of nuclide production in nuclear reactor cores. Currently, we are developing a calculation code that enables detailed analysis of the entire reactor cores, a nuclear data processing code that connect nuclear data and calculation codes, methods for uncertainty quantification of the reactor-design parameters, and integral tests of evaluated nuclear data.

In the field of thermal-hydraulics, we are developing 3-dimensional thermal-hydraulics simulation techniques in nuclear reactor systems based on the numerical method with large scale computers. In this technology development, evaluation methods for predicting steam-water flow and melted material behavior by using state-of-the-art computer science technology and super-parallel computers have been developed. In order to verify and validate the applicability of the developed evaluation methods, measurement techniques have been also developed.

Furthermore, we are developing an advanced coupled neutronics and thermal-hydraulics simulation code system as a crossover field of reactor physics and thermal hydraulics. It is becoming more and more difficult to conduct critical and thermal-hydraulics experiments in the real world due to the decommission of existing criticality and thermal hydraulics test facilities. We are, therefore, developing the coupled neutronics and thermal-hydraulics simulation code that allows numerical experiments to be performed in a virtual world. We are not only improving computer codes for single physics but also developing a computational platform to realize multiphysics simulation as well as mechanism-based methods that eliminate approximations as much as possible.