Tritium study in Japan (for more than 40 years)

1. Tritium study in Japan(for more than 40 years) Satoru Tanaka The University of Tokyo

2. Blanket Engineering Structural Materials Heat Removal Tritium Production and Recovery Breeding Materials Tritium Breeding Ratio Tritium Recovery Tritium Reakage

3. Institutes and Universities where Tritium Related Studies are begin conducted in Japan JAEA JAEA

4. Research Resources University Researchers Students Hokkaido U. 3 4 Tohoku U. 2 2 Ibaraki U. 6 6 U. Of Tokyo 7 6 Shizuoka U. 5 4 Toyama U. 12 7 NIFS 7 0 Nagoya U. 7 10 Kyoto U. 7 7 Osaka U. 2 1 Hiroshima U. 2 2 Kyushu U. 9 8 Kumakoto U. 1 2 Total 70 59 JAEA 50 NIRS 10 Industries many

5. Research Subjects and Institutes Research Subjects • - Fusion (Processing, Blanket, First Wall, Safety, Licensing) • Fission Reactor (Heavy Water Reactor) • Waste Management • Environmental Behavior • Biological Effects • Fundamental Science Institutes • Japan Atomic Energy Agency • Universities • National Institute for Fusion Science (NIFS) • National Institute of Radiological Sciences (NIRS)

6. Tritium Network Academic Societies ・Atomic Energy Society of Japan ・The Japan Society of Plasma Science and Nuclear Fusion Research ・The Japan Radiation Research Society Universities NIFS JAEA Conferences (International and Domestic) ・Tritium Science and Technology ・ISFNT ・Joint Symposium, ・・・・・ National Institutes Industries

7. Many International Collaborations • CUP (Core Universities Program) • MEXT/Korea-STA • MEXT/US-DOE • JAEA and foreign countries • -ITER • -Between Universities • -International Conferences and Symposiums

8. (1) Tritium Engineering and Science for Fusion Reactor Fuel Cycle for ITER JAEA Safety in ITER JAEA Licensing for ITER JAEA Tritium Behavior JAEA and Universities in Large Tokamaks Tritium Production JAEA Blanket JAEA, U. of Tokyo, Kyushu U., Kyoto U, Shizuoka U. First Wall JAEA, Hokkaido U. U. of Tokyo, Shizuoka U. Kyushu U. Material Interaction U. of Tokyo, Shizuoka U., Nagoya U. Toyama U., Kyushu U., Kyoto U., JAEA Safety JAEA, NIFS, Ibaraki U., U. of Tokyo Detection and Measurement Toyama U., JAEA Contamination and JAEA, U. of Tokyo Decontamination Tritium in ICF Pellet Osaka U.

9. (2) Tritium in Fission Reactor Tritium Control in Heavy Water Reactor : JAEA Decommissioning of Heavy Water Reactor (Advanced Thermal Reactor Fugen) JAEA Tritium Control in Fast Breeder Reactor : JAEA Tritium Control in Gas Cooled Reactor : JAEA (3) Tritium in Waste Management Tritium in Radioactive Waste : JAEA, Utility Companies Management of Tritium Waste : JAEA (4) Tritium in Reprocessing Plant Behavior in plant and environmental effect JNFL

10. Tritium Fuel Cycle Development -Tritium processing technology -Tritium safe-handling technology development Tritium Breeding Blanket Development -Fabrication of breeder pebbles and irradiation experiments -Neutron Multiplier Activity on Tritium Production -Establish tritium production technology through the trial production of the level of 0.1 g/year Tritium Research in JT-60 and a Large Tokamak Decontamination and Decommissioning Technology Development on JRR-2, a Heavy Water Research Reactor Environmental and Health Physics Research

11. TiO2-doping TiO2-doping : Un-doped : 5mol% : Un-doped : 10mol% : 5mol% Tritium Breeding Blanket Development-Fabrication of breeder pebbles and irradiation experiments 2) Characterization Tritium Breeder Material 100 Fabrication method : wet process - Elemental fabrication technology of Li2TiO3 was established. - Oxide-doped Li2TiO3 is to be selected as an advanced material. 90 80 Grain size : < 5 m Density (%T.D.) 70 - Control of grain size - Chemical stability Target value 1) Pebble Fabrication Development 60 - Success in fabrication of 6Li-enriched (30 and 95at%) Li2TiO3 pebbles and TiO2-doped Li2TiO3 pebbles by indirect wet process. 50 0 10 20 30 Grain size (mm) 1.5 Sweep gas : Ar+0.1%H2 1.0 H2 reaction rate (mmol/g/min) H2 reaction rate of un-doped Li2TiO3 was small. 0.5 0 500 600 700 800 900 1000 Temperature (˚C)

12. Structural material : SS316LN 70 Heating Temp. : 600˚C Neutron Multiplier Material 60 : Be-5at%Ti 50 : Be-7at%Ti - Fabrication technology of Be pebble was established. - Be-Ti alloys are to be selected as an advanced material. : Be-8.5at%Ti 40 : Be Reaction thickness (mm) 30 Arc He 20 about 1/10 10 - High melting point - Low oxidation W electrode 0 1) Pebble Fabrication Development Motor 0 5 10 15 20 25 30 35 Heating time (h1/2) Electrode Be-7at%Ti pebbles Steam reaction rate of Be12Ti is about 1/1000 of that of beryllium metal. 1mm Main Properties Results Evaluation Compatibility with SS <1/10 of Be Good Swelling <1/50 of Be Good [Anderl, R. A., etal, J. Nucl. Mater. 258-263(1998) 750-756] Lower release temp. Smaller inventory Tritium inventory Good Tritium Breeding Blanket Development-Neutron Multiplier Grain size (mm) 2) Characterization of Be-Ti Alloys (Be12Ti)

13. JAEA (JNC)Drs. Sasaki, Kitamura, Oota, Sato • Tritium Control at FUGEN • ATR (165MWe, D2O moderated, H2O Cooled, D2O: 160m3, D2O in core is circulated, 20 years’ op.) • Tritium Measurement, Maintenance, D2O purification, • Release Control • - Decommissioning started • Tritium Control at JOYO • Experimental reactor of FBR, since 1977 • Tritium concentration measurement • (several kBq/g) • Database for tritium behavior in FBR • Tritium Waste Engineering, 5MBq • -Radionuclide migration in bentonite rocks

14. Hokkaido UniversityProfs. Hino, Hirohata, Yamauchi • Estimation of Tritium Inventory of Carbon Dust in ITER • Systematic data on tritium inventory of carbon dust by D experiment • Fuel Hydrogen Retention of Plasma Facing Materials • -Hydrogen isotope retentions in Carbon, SiC, B4C, W, Li after D irradiation were measured. • Hydrogen Embrittlement of Low Activated Materials • -Vanadium alloy, Titanium alloy (absorption amount, oxide coating)

15. Ibaraki UniversityProfs. Ichimasa and Tauchi • Environmental Tritium • Heavy water release experiment as a substitute for tritium • Oxidation of atmospheric tritium gas by soil and soil microbes • Application of tritium gas oxidizing bacteria to tritium recovery system • Tritium Metabolism • -Food Chain of Tritium • -Mitigation of Radiation Injury Development of a Hyper-Sensitive Mutation Detection System for Estimation of Biological Risk of Low Dose Tritium Radiation

16. The University of TokyoProfs. Tanaka, Terai, Suzuki, Oya, Nishimura Hydrogen isotope behavior in various materials for fusion reactor materials -Tritium breeding blanket materials Li2O, Li2TiO3, LiAlO3 Flibe, liquid metal, molten salt -Fusion structural materials Fe, Fe-Ti alloy, Stainless steel -First wall materials Graphite, SiC Deuterium desorption behavior for SiC

17. Shizuoka UniversityProfs. Okuno, Yoshioka • Chemical behavior of high energy hydrogen isotopes in various plasma facing materials • Graphite, SiC, WC, boron thin film • Radiochemical studies on tritium behavior produced in various lithium compounds • Li4SiO4, LiAlO2, Li2ZrO3, Li2TiO3 • Development of high sensitive tritium monitoring system using hollow filament polyimide membrane • Tritium-induced scission of DNA and protection mechanism by EGCg (EpGallo-Catechin Gallate) Plasma CVD system for preparing boron film TDS spectra of D2 for boron film Total energy of hydrogen in boron by Gaussian 03

18. Toyama UniversityProfs. Matsuyama, Hatano, Torikai, Hara Tritium 200 Ci/year Fundamental studies on physicochemical properties of hydrogen isotopes to establish the safe handling technique of a large amount of high concentration tritium In-situ measurement of Tritium Retained on Metal surface Tritium Decontamination of Type 316 Stainless Steel Hydrogen Absorption and Disproportioation Behavior of Zr2Co BIXS spectra and tritium depth profiles before and after decontamination Typical X-ray spectrum observed tritium irradiated graphite Hydrogen absorption behavior of Zr2Co at 773K

19. Nagoya UniversityProfs. Yamamoto, Enokida Tritium 1 mCi Isotope Separation by Thermal Diffusion, Water Distillation, Solvent Extraction etc. by Advanced and Systematic Theory and Experiments Exchange of D (or T) Implant into Oxide Ceramics with H in Air Vapors Exposed at Room Temperature

20. Kyoto UniversityProfs. Konishi, Moriyama, Fukui, Yamamoto, Takagi Liquid Li-Pb Loop study Tritium Recovery from Lithium Ceramics -Irradiation effect Environmental Behavior and Detection -Food Chain, Modeling -Detection after enrichment using solid electrolysis Biological Dose, Model and Experiment -MTC model -Evaluation of OBT effect -Dose evaluation to the marrow Experiment by mouse Tritium Behavior in the Facility LiPb loop in Kyoto University

21. Osaka UniversityProf. Norimatsu Tritium 150 Ci Tritium Pellet Manufacturing -glass pellet, 10mCi/pellet -explosion in chamber, unburned tritium to pellet factory Plastic Target Production by UV Irradiation and Isotope Exchange

22. Kyushu UniversityProfs. Nishikawa, Tanabe, Fukada, Munakata Tritium 1 Ci/year 1mCi/experiment Safety Confinement Fuel Cycle Breeding Blanket Mass Effect of Diffusion in Solid Materials Application of Tritium Autoradiography for Materials study Tritium Distribution in JT-60, JET, TFTR Graphite Tiles by Imaging Plate Technique Removal of Tritium in Plasma Facing Materials: ESD, LSD Hydrogen Behavior in Graphite

23. Kumamoto UniversityProf. Momoshima Tritium concentration in different isotopic composition of atmospheric hydrogen -Chemical form of Tritium (T2, DT or HT?) Relation between tritium concentration and acidity of rain in japan -tritium migration to Japan Enrichment apparatus of atmospheric hydrogen

24. Tritium Behavior in Reprocessing Plant and Its Environmental Effect • 100Ci-T/ton of SF • Tritium Behavior in plant: to liquid effluent, to gaseous effluent • Environmental effect • Environmental behavior • Chemical form change (HT, HTO, OBT) • Biological Effect • (Fundamental study to recover tritium)

25. Tritium Behavior and Effect in Radioactive Waste Management • Tritium in Hull (Fuel clad separated in reprocessing plant) • Tritium Release during storage • Radiation effect (HT gas)

26. Conclusions • All Kinds of tritium studies related to fusion, fission, environmental behavior and biological effects • Efficient collaboration among JAEA, Universities, National Institutes and Industries • International collaborations are important to promote tritium studies • Can contribute to the world-wide project such as ITER