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Komiyama, Daisuke; Amaya, Masaki
Journal of Nuclear Science and Technology, 54(12), p.1338 - 1344, 2017/12
Times Cited Count：1 Percentile：9.81(Nuclear Science & Technology)Komiyama, Daisuke; Amaya, Masaki
JAEA-Research 2016-013, 20 Pages, 2016/08
JAEA-Research-2016-013.pdf:6.05MB
The boric acid in the coolant may precipitate on the fuel cladding surface in the case that the blockage of coolant flow path etc. occurs and/or the cooling of fuel becomes insufficient during a LOCA (Loss-Of-Coolant Accident) in PWRs. While there is much knowledge about the compatibility between Zircaloy-4 and boric acid under normal operation conditions, such knowledge under high temperature condition, e.g. LOCA, has not been sufficient. In this study, isothermal heating tests were carried out by using Zircaloy-4 plates with solid boric acid in various atmospheres at up to 900
C; and the stability of boric acid, the reaction between Zircaloy-4 and boric acid and the effect of solid boric acid on the high temperature oxidation behavior of Zircaloy-4 were investigated. From the results obtained, it was suggested that, if boric acid anhydride remained on the surface of Zircaloy-4, the boric acid anhydride prevented the surface of Zircaloy-4 from contacting oxidizing atmosphere and mitigated the high-temperature oxidation of Zircaloy-4. In the case that solid boric acid adhered to the surface of pre-oxidized Zircaloy-4 and they have been heated up to high temperature, it was indicated that the solid boric acid penetrated into the gaps in the pre-oxide layer and the penetrated solid boric acid mitigated the oxidation of Zircaloy-4 thereafter.
Usui, Takahiro; Komiyama, Daisuke; Amaya, Masaki; Suzuki, Akihiro*; Terai, Takayuki*
no journal, ,
Oxidation experiments of the SiC coating on the Zry-4 plates were conducted. It was observed that the SiC coating on the Zry-4 specimens has oxidation resistance at 1200C for 30 min. The peel-off of the coating were observed at 1000C and more. It is possible that the peel-off of the coating was affected by the reaction between SiC coating and Zry-4 substrates.
Komiyama, Daisuke; Amaya, Masaki
no journal, ,
no abstracts in English
Sato, Daiki*; Watanabe, Seiichi*; Komiyama, Daisuke*; Furumoto, Kenichiro*; Okamoto, Michiaki*; Yamato, Masaaki*; Yamashita, Shinichiro; Fukahori, Tokio
no journal, ,
It is expected that SiC cladding tube has high corrosion resistance and high strength under LOCA condition in existing PWR. There is little data for SiC cladding tube in the high temperature environment. So the apparatus which was capable of testing at LOCA simulated condition was manufactured for SiC cladding tube. The modified LOCA test was carried out for investigating the behavior of SiC cladding tube.
Komiyama, Daisuke
no journal, ,
