The water treatment system for the highly contaminated water at Fukushima I Nuclear Power Plant has been stopped by TEPCO in the early morning of June 18. The system had been on the full "hot" run since 8PM on June 17.
The full run was halted in less than 6 hours due to high radiation level on the cesium absorption towers by Kurion.
The water treatment system is supposed to treat 1,200 tonnes of highly contaminated water every day, or 50 tonnes per hour.
From Yomiuri Shinbun (12:07PM JST 6/18/2011):
TEPCO announced on June 18 that it stopped the water treatment system for the highly contaminated water at Fukushima I Nuclear Power Plant at 12:54AM on June 18.
The stoppage was not due to system malfunction, TEPCO explained. The company stopped the system when the radiation level of the cesium absorption subsystem [by Kurion] had reached the set limit earlier than expected. TEPCO had planned to start the cooling water circulation system whereby the treated water is injected back into the Reactor Pressure Vessels on June 18, but it is not clear whether it will start as scheduled.
セシウム吸着装置は集中廃棄物処理施設の中に設置されている。交換式の吸着剤が入った容器が６本１組で４列配置され、線量が毎時４ミリ・シーベル トに達すると吸着剤を交換することになっている。東電によると、システムは１７日午後８時に本格稼働したが、遠隔操作中の作業員が、セシウム吸着装置の容 器表面の線量計の値が４・７ミリ・シーベルトになっていることに気づいた。
The cesium absorption subsystem is set up inside the Central Waste Processing Facility. There are 4 rows of 6 cylinders that contain cesium absorption material [zeolite], and when the radiation level reaches 4 millisieverts/hour the cylinders are to be replaced. According to TEPCO, the system started the full run at 8PM on June 17, but the worker who was remote-operating the system noticed that the radiation measurement device on the surface of the cesium absorption cylinders was 4.7 millisieverts/hour.