Lesson on LBE control techniques taken from JLBL1 loop

Kikuchi, Kenji; Saito, Shigeru   ; Hamaguchi, Dai; Tezuka, Masao

JLBL-1 operation has been done over 18000 hrs to get design data for LBE spallation target in J-PARC facility. Interested materials are austenitic steel because electro-magnetic pump needed non-magnetized materials. The loop was made mainly by SS316 in order to know mass traveling in the closed system. The temperature difference was 50-100 C and flow rate was 1 m/s at the test section. Active control of oxygen concentration in the system was not done but inert gas was used to separate LBE from oxygen environment. Oxygen sensor was set up in the loop later. We experienced blockade of pass in the pump, mass transfer from hot parts to cold parts, precipitations of dissolved components from materials. Lead bismuth was sampled from the loop and replaced by new one. Electro-magnetic flow meter was inspected to take output change into consideration. Most important thing experienced hitherto was a find of erosion-corrosion in the narrow path at the high temperature test section.