The effects of surface roughness, oxidation level, and liquid subcooling on the minimum film boiling temperature, Tmin, during quenching of a nuclear fuel rod were investigated experimentally. An instrumented nuclear fuel rod simulator (FRS) was designed and fabricated with different combinations of cladding (Inconel and Zircaloy) and filler (BN and Al2O3) materials. Surface roughness was varied by polishing the FRS with different grades of emery cloth, whereas oxidation level was varied by heating the FRS in an oven under carefully controlled conditions for different time periods. An eddy-current device was used to nondestructively measure the oxide layer thickness on the FRS. Quenching experiments were conducted in a subcooled water bath and the value of Tmin was determined from the measured temperature transients. For the FRS explored in the experiments, the minimum film boiling temperature was found to depend strongly on the liquid subcooling, oxidation level, and surface roughness.
All Science Journal Classification (ASJC) codes
- Control and Systems Engineering
- Electrical and Electronic Engineering