ITW water system maintenance is done. All working paddle wheels and coils are replaced. ITW water system polyurethane tubes are replaced as well. Two 3/8" leak small valves on return lines are replaced. 85 liters of tritium water are transferred from storage tank to B2 level holding tank. LALC water are refilled into S-tank. Restarted pump and checked system. Everything works fine now. No water leak has been found so far.