Measurement of void fraction distribution at high pressure in 44 simulated fuel bundle for validation of thermal-hydraulics simulation codes

Nagatake, Taku ; Shibata, Mitsuhiko ; Uesawa, Shinichiro  ; Ono, Ayako ; Yoshida, Hiroyuki  

JAEA is developing a neutronics/thermal-hydraulics coupling simulation code for light-water reactors. Thermal-hydraulic simulation codes applied to the platform are expected to evaluate void fraction distributions in fuel assemblies under operational conditions, which is necessary for neutron transport simulation, and need to be validated using void fraction distribution data in a rod bundle under high-temperature and high-pressure conditions. To obtain the data for code validation, we have been measuring the instantaneous void fraction distribution in a 44 simulated fuel assembly by a wire mesh sensor. In this paper, we report the results of the experiments with pressure and flow rate as parameters at a maximum pressure of 2.6 MPa.