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Nakanishi, Yoshiki; Chinone, Makoto
no journal, ,
no abstracts in English
Kato, Shinya; Matsuba, Kenichi; Kamiyama, Kenji
no journal, ,
In order to clarify the event progression and its influential factors in the core disruptive accident of the sodium-cooled fast reactor, JAEA has carried out EAGLE(Experimental Acquisition of Generalized Logic to Eliminate re-criticalities)-3 project with the cooperation of National Nuclear Center of the Republic of Kazakhstan. The result of the out-of-pile test focused on the outflow of the molten-core material through the control rod guide tube will be shown.
Do, V. K.
no journal, ,
In this study, an ultra compact device for analysis of radioactive element has been developed by liquid electrode plasma optical emission spectrometry (LEP-OES) which can be possible to miniaturize the analytical equipment. The applied voltage with its sequence and nitric acid concentration are optimized and then cesium (Cs), strontium (Sr) and technetium (Tc) are measured. It is found that Cs, Sr and Tc are determined within the concentration range from ppm to ppb. Also, Cs and Sr concentration in real highly active liquid waste (HALW) are determined. The concentration of Cs and Sr in HALW agree well with the value of ORIGEN calculation. Moreover, Sr-resin from Eichrom Technology is used for solid phase extraction preconcentration and combined with LEP-OES. It is found that Sr can be preconcentration to a factor of 15 and Sr in simulated HALW are measured with the volume of 5 mL.
Sudo, Ayako; Poznyak, I.*; Nagae, Yuji; Nakagiri, Toshio; Kurata, Masaki
no journal, ,
no abstracts in English
Yamamoto, Keisuke
no journal, ,
no abstracts in English
Ishizuka, Ippei*; Takebe, Toshihiko*; Yamada, Tomonori
no journal, ,
no abstracts in English
Tsuji, Mitsuyo
no journal, ,
To elucidate the core cooling systems of a sodium-cooled fast reactor under severe accident, PIV experiments were carried out by using scaled water experimental facility simulating the condition of uniformly-accumulated debris on the core catcher, measured the natural convection flow field in starting up the submerged type DHX. The authors confirmed the specific flow patterns that low temperature fluid flowed down along the core wall and flowed into lower plenum, and the fluid was heated on the core catcher and elevated toward the center of reactor core, then some vortexes were formed by the mutual interaction due to the down-flow of low temperature fluid and up-flow of elevated temperature fluid. Furthermore, the equivalent flow field and the maximum flow velocity were observed compared with the existing knowledge.
Taniguchi, Takumi; Irisawa, Keita; Namiki, Masahiro*; Nakazawa, Osamu
no journal, ,
no abstracts in English
Sato, Junya; Irisawa, Keita; Takaoka, Masaki*; Nakazawa, Osamu
no journal, ,
no abstracts in English
Harada, Makoto; Arima, Tatsumi*
no journal, ,
Melting temperature of nuclear fuels is important for safety assessment in nuclear reactor. In conventional method, they were measured using a metallic capsule, but a small extent of reactions was observed. In this study, laser surface melting method was applied. This method is to melt about 1 mm diameter of sample's surface, so container isn't needed. On the other hand, this method measures temperature from the sample directly, so its emissivity has to be determined. Therefore, some devices was used to measure its emissivity. In this study, Platinum and Black ZrO
were used as a reference and a surrogate material, respectively. Using integrating sphere, melting temperature of Platinum was obtained at 7% lower than reference value and of Black ZrO was enabled to obtained with changing the condition of laser heating. Using multichannel spectrometer, it was calibrated using a blackbody furnace and thermal radiation spectrum of samples in freezing point was obtained.
Okada, Jumpei; Nishino, Saki; Terunuma, Ryuki; Takahashi, Naoki; Isomae, Hidemi
no journal, ,
no abstracts in English
Shimizu, Koki
no journal, ,
no abstracts in English
Horikawa, Ayumi
no journal, ,
no abstracts in English
Emura, Yuki; Kamiyama, Kenji; Matsuba, Kenichi; Isozaki, Mikio
no journal, ,
In case of core disruptive accident in sodium-cooled fast reactors, it is thought that molten-core material will be discharged into the lower plenum and fragmented there due to fuel-coolant interactions. To understand this fragmentation behavior, we performed the simulation test in which molten stainless steel discharged into sodium pool and fragmentation behavior was observed using a visualization system combined X-ray and high-speed camera. Both successful visualization of fragmentation behavior by above visualization system and rapid cooling of molten stainless steel due to fragmentation are presented in this study.
Uchida, Masahiro; Tsuchiko, Yasuhiro*; Suto, Yudai*; Hoshi, Katsuya
no journal, ,
no abstracts in English
Hamataka, Kazuhito; Hoshi, Katsuya
no journal, ,
no abstracts in English
Kato, Yoshinari; Hashimoto, Makoto; Miyauchi, Hideaki; Yasumune, Takashi; Ogawa, Ryuichiro; Goto, Shingo; Ochiai, Yukihiro*; Matsui, Junki
no journal, ,
no abstracts in English
Ishimaru, Masaru; Maeda, Shigetaka; Miura, Yoshiyuki; Suzuki, Toshiaki
no journal, ,
no abstracts in English
-ray-induced phase transformationOkuno, Yasuki
no journal, ,
In the accelerator driven system, it is necessary to suppress erosion and corrosion of stainless steel piping by oxygen control of lead bismuth eutectic alloy (LBE). An oxygen sensor using yttria-partially-stabilized zirconia (PSZ) is effective for measuring the oxygen concentration in LBE, and it need to be understood about the influence of radiation during ADS operation. In this study, it was observed that phase transformation from tetragonal to monoclinic crystal occurred when 
Co -ray was exposed to the PSZ. From the calculation result of the radiation behavior simulation analysis, it has been clarified that this phase transformation was caused by the ionization effect. In this presentation, we report on the phase transformation mechanism of PSZ due to this ionization effect attributed to the radiation.