Abstract
A concept of lead-bismuth (Pb-Bi) cooled direct contact boiling water small fast reactor (PBWFR) is proposed as safety fast breeding reactors. Gas lift pump, injecting and boiling water in a molten lead-bismuth pool, can simplify the reactor constitution and make the volume smaller. The visualization of boiling bubbles by gamma-ray radiography is useful for investigation of thermal-hydraulics in the gas lift pump. A conceptual design of a test apparatus for the visualization test is provided.
