We present three nuclear/hydrogen-related R&D activities being performed at KAIST: air-ingressed LOCA analysis code
development, gas turbine analysis tool development, and hydrogen-production system analysis model development. The ICE
numerical technique widely used for the safety analysis of water-reactors is successfully implemented into GAMMA, with which
we solve the basic equations for continuity, momentum conservation, energy conservation of the gas mixture, and mass conservation
of 6 species (He, N2, O2, CO, CO2, and H2O). GAMMA has been extensively validated using data from 14 test facilities. We
developed a tool to predict the characteristics of HTGR helium turbines based on the throughflow calculation with a Newton-
Raphson method that overcomes the weakness of the conventional method based on the successive iteration scheme. It is found that
the current method reaches stable and quick convergence even under the off-normal condition with the same degree of accuracy.
The dynamic equations for the distillation column of HI process are described with 4 material components involved in the HI
process: H2O, HI, I2, H2. For the HI process we improved the Neumann model based on the NRTL (Non-Random Two-Liquid)
model. The improved Neumann model predicted a total pressure with 8.6% maximum relative deviation from the data and 2.5%
mean relative deviation, and liquid-liquid-separation with 9.52% maximum relative deviation from the data.