Reducing radioactivity in high level high level radioactive water accumulated in turbine buildings and trenches, and to utilize it for cooling the reactors are important actions in the roadmap toward restoration of the site.We began construction of a radioactive water treatment facility for the accumulated water transferred and stored in the Centralized Radiation Waste Treatment Building from the beginning of May. Now we have completed installing the components and are aiming to start the operation of the facility in middle of June. Contacts:
TEPCO Washington Office: 202-457-0790
Kenji Matsuo, Director and General Manager
Ikuo Nishimura, Deputy General Manager,
Masayuki Yamamoto, Manager, Nuclear Power Programs
Radioactive Water Treatment System for High Level Radioactive Water
In order to remove oil from water transferred to the Centralized Radiation Waste Treatment Building, and decrease the radioactivity level, together with removing salt, the facility is composed of oil separators, radioactive material treatment instruments, and water desalinations.Our plan is to process 25,000 m3 of high level radioactive water in about a year (300 days). Process capability is 1,200 m3 per day and we have already had 10,000 m3 in turbine buildings as of the end of May and assuming all injected water into the reactors, 500 m3 per day, would flow in the turbine buildings, we will have additional 15,000 m3 (500 m3 x 300 days) and total amount of water will be 25,000 m3 (10,000 m3 + 15,000 m3).We expect to reduce radioactivity by the order of 106 .(Kurion’s Cs absorber would reduce by the order of103 and Areva’s process would decontaminate by the order of 103 – 104 ) 
By using low level contaminated water stored in the suppression pool water surge tank, we will check the function of the whole system in duration of about a week.
－Function Test by Cesium absorption instruments on a stand-alone
－Function Test by decontamination instruments on a stand-alone
－Total Function Test
Tests will start on June 10 and it will take about a week to complete all tests.
・ Oil separators
Ø Oil separators remove oil and sludge in accumulated water by dissolved air flotation.
・ Cesium absorbers
Ø Cesium absorbers (Kurion (US)) remove contaminated materials by flowing water through vessel filled with three kinds of absorbers.
Ø This is an improved design of the water treatment system used for TMI accident.
・ Decontamination Process
Ø Decontamination Equipment (Areva, France) remove radioactive materials by mixing the contaminated water in the tank, injecting chemicals, developing precipitation and extracting the purified upper layer.
Ø This process has been used for the reprocessing plant at La Hague, France.
・ Desalination Process
Ø Accumulated water which are treated though Oil separators, Cesium absorber and Decontamination process is desalinated by using reverse osmosis membrane (RO).
Ø Water desalination equipment (distiller) is also planned to be in operation in line with water desalinations (RO), in August and October.
- TEPCO English website
- METI(Ministry of Economy Trade and Industry)
- NISA(Nuclear and Industrial Safety Agency)
- JAIF(Japan Atomic Industrial Forum Inc.)
- FEPC(The Federation of Electric Power Companies of Japan)
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