Removal and control of tritium in lithium target for International Fusion Materials Irradiation Facility (IFMIF)

Nakamura, Hiroo; Ida, Mizuho*; Sugimoto, Masayoshi; Yutani, Toshiaki*; Takeuchi, Hiroshi

This paper presents the design considerations on removal and control of tritium generated in liquid lithium target of International Fusion Materials Irradiation Facility (IFMIF). In the IFMIF, intense neutrons simulating fusion condition are produced by injecting deuterium beam with a maximum energy of 40 MeV and a maxim current of 250 mA into the liquid lithium flow with a speed of 20 m/s. Tritium is produced by direct reactions of the beam with the lithium. Total production rate is estimated to be about 10 g/year.As a reference method of the tritium removal, a cold trap with a swamping method is used. As an option, yttrium getter hot trap is considered. The concentration of hydrogen isotopes in the Li flow is detected by measuring their partial gas pressure which comes through a Nb or Nb-Zr membrane. To distinguish the isotopes from the other, a quadrupole mass spectrometer is used. The off-line sampling system is also used to measure the tritium concentration in the lithium.