2021 Fall Meeting

Presentation information

Oral presentation

V. Nuclear Fuel Cycle and Nuclear Materials » 505-3 Decommissioning Technology of Nuclear Facilities

[2C10-15] Decommissioning Technology for Fukushima 1

Thu. Sep 9, 2021 2:45 PM - 4:25 PM Room C

chair: Kazuya Idemitsu (Kyushu Univ.)

4:00 PM - 4:15 PM

[2C15] Development of Fuel Debris Canister

(18)Catalytic hydrogen recombination

*Nobuyuki Ukai1, Hideaki Uchiyama2, Yasufumi Miyahara3, Yuuichi Matsushita4, Toshihiro Matsuoka1, Taisuke Tsukamoto1, Yasuhiro Tomiita1, Naotaka Uchimichi1 (1. IRID/MHI, 2. IRID, 3. IRID/TOSHIBA ESS, 4. IRID/HGNE)

Keywords:Fuel Debris, Fuel Debris Canister, Hydrogen Recombination, Catalyst

This paper reports the result of examination of hydrogen recombination by catalyst in fuel debris canister. When fuel debris is transferred to a storage building, measures against hydrogen accumulation due to radiation decomposition of moisture remaining in the fuel debris are an issue. As one of the countermeasures, this paper examines a technology to keep hydrogen concentration in a transfer container and a fuel debris canister below the explosion lower limit (hydrogen concentration of 4 vol%) by recombining hydrogen and oxygen by a catalyst.
When using the catalyst, it is necessary to consider humidity, room temperature and high radiation as environmental conditions in the fuel debris canister. Then, the dependence of hydrogen recombination rate on environmental conditions (wind velocity, temperature, oxygen/hydrogen concentration ratio, hydrogen concentration, etc.) was grasped by the test, and the catalyst quantity and catalyst arrangement plan suitable for the hydrogen generation quantity were examined from the obtained performance. Problems in practical application were also summarized.