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Oct 13 – 18, 2014
Hotel Park Inn Pribaltiyskaya
Europe/Moscow timezone

Development of Tungsten Monoblock Technology for ITER Full-Tungsten Divertor in Japan

Oct 13, 2014, 4:40 PM
Blue 1-5 (Hotel Park Inn Pribaltiyskaya)

Blue 1-5

Hotel Park Inn Pribaltiyskaya

Saint Petersburg, Russian Federation
Oral FIP - Fusion Engineering, Integration and Power Plant Design ITER Technology


Mr Yohji Seki (Japan Atomic Energy Agency)


Through R&D for a plasma facing unit (PFU) of a full-tungsten (W) ITER divertor, Japan Atomic Energy Agency (JAEA) succeeded in demonstrating the durability of the W divertor which endured a repetitive heat load of 20 MW per sqare meter without macroscopic cracks of all W armors. At the beginning of this activity, the bonding technology armor to heat sink was one of the most important key issues in a manufacturing process. JAEA improved the bonding process of the W divertor mock-ups. At first the bonding between the W armor and the copper interlayer (Cu) is performed by using several technologies, such as "Direct casting of Cu" or "Diffusion bonding" or "HIP bonding". Then the brazing between the Cu and the cooling pipe is done. Then the rejection rate due to those bonding processes has been significantly been reduced. As a performance test for the bonding and a heat removal capability, the high heat flux testing was carried out for 6 small-scale mock-ups for the R&D of the full-W ITER divertor. Moreover, a W part of 4 full-scale prototype PFUs were also tested. In the tests, all of the W monoblocks endured the repetitive heat load of 10 MW per sqare meter for 5,000 cycles and 20 MW per sqare meter for 1,000 cycles without the macroscopic crack, which strongly encourages the realization of the full-W divertor target from the start of the operation in ITER. This paper presents the latest R&D activities on the full-W ITER divertor in JAEA.
Paper Number FIP/1-2Ra
Country or International Organisation Japan

Primary author

Mr Yohji Seki (Japan Atomic Energy Agency)


Mr Frederic ESCOURBIAC (ITER Organization) Mr Kenji Yokoyama (Japan Atomic Energy Agency) Mr Kensuke Mohri (Japan Atomic Energy Agency) Dr Koichiro Ezato (Japan Atomic Energy Agency) Dr Satoshi Suzuki (Japan Atomic Energy Agency) Dr Takeshi Hirai (ITER Organization) Mr Vladimir Kuznetsov (NIIEFA)

Presentation materials