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Yokoyama, Kenji; Yamamoto, Akio*
no journal, ,
no abstracts in English
-ray irradiationMotooka, Takafumi; Nagaishi, Ryuji; Yamagishi, Isao
no journal, ,
We conducted ray irradiation test using simulated carbonate slurry to obtain the basic knowledge of the cause of stagnant water over the High Integrity Container. We observed a rise in water level, air bubbles in the slurry, a supernatant when the carbonate slurry with 95 g/L density was irradiated by ray at 8.5 kGy/h. The cause of the rise in water level was regarded as the volume expansion by the gas retention in the carbonate slurry.
Sasaki, Takayuki*; Akimoto, Yuji*; Seki, Kotaro; Nagano, Misato*; Ishimori, Kenichiro; Ueno, Takashi; Kameo, Yutaka
no journal, ,
no abstracts in English
-concrete system under randomizationUeki, Taro
no journal, ,
Analysis framework under indeterminate material distribution is investigated for the Monte Carlo (MC) criticality calculation of continuously mixed media formed via molten core concrete interaction. Randomized Weierstrass functions (RWF) are utilized to represent the volume fractions of constituent materials. The possibility of several percent fluctuation of effective multiplication factor is shown by the MC simulation with delta-tracking.
Sato, Yuki; Kishimoto, Aya*; Kaburagi, Masaaki; Kataoka, Jun*; Torii, Tatsuo
no journal, ,
no abstracts in English
Edao, Yuki; Iwai, Yasunori; Sato, Katsumi; Hayashi, Takumi
no journal, ,
no abstracts in English
Yamashita, Susumu; Takase, Kazuyuki; Monji, Hideaki*; Yoshida, Hiroyuki
no journal, ,
no abstracts in English
4 bundleLiu, W.; Nagatake, Taku; Jiao, L.; Shibata, Mitsuhiko; Komatsu, Masao*; Takase, Kazuyuki; Yoshida, Hiroyuki
no journal, ,
To improve and validate the prediction accuracy of two - phase codes, Japan Atomic Energy Agency is working on the measurement of void faction distribution in rod bundles with using wire mesh sensors, under high pressure and high temperature conditions (2MPa, 212
C). The test section is a 44 rod bundle, in which two three - layer 99 wire mesh sensors are installed at two different axial positions. As the first step of the experiment, to validate the measuring system, we performed experiments in water - air system under atmospheric pressure, with using water and air flow rates as parameters. Void fraction distributions in the sub-channels of the rod bundle were derived in a wide flow pattern from bubbly flow to slug flow. The water flow rate, from the viewpoint of considering the natural circulation after reactor scrum, was lower than 600 kg/m
s. The data will be used to validate the void fraction correlations and two-phase evaluation codes.
Jiao, L.; Takase, Kazuyuki; Liu, W.; Nagatake, Taku; Uesawa, Shinichiro; Yoshida, Hiroyuki; Shibata, Mitsuhiko
no journal, ,
To construct a database for upwards air/water flows in a vertical pipe, extensive measurements of air/water flows in a vertical pipe using the wire-mesh sensor technology were conducted at the thermal fluid dynamic test facility TPTF of the Japan Atomic Energy Agency. The test section is 4m in length and 58mm in inner diameter, two sets of three-layers-WMS were set separately at the 1.15m and 1.65m elevation of the air injection position. Air was injected from the bottom of the pipe through 0.6mm/1mm/2mm diameter nozzles. The obtained data are characterized particularly by their quantity and their detailed information on important two-phase flow parameters (e.g. radial distribution of the void fraction, the gas velocity and the time and cross-section averaged bubble size distribution for different test section heights). In the near future, we would like to use the WMS to measure the detailed two-phase flow in sub-channels of a simulated bundle flow.
Nagatake, Taku; Takase, Kazuyuki; Yoshida, Hiroyuki
no journal, ,
no abstracts in English
Itakura, Mitsuhiro; Okita, Taira*
no journal, ,
Time to hydride precipitation in Zircalloy fuel cladding determines the lifetime of the fuel cladding of nuclear reactors. For the design of a new reactor with increased irradiation to transmute TRU elements and reduce waste, the effect of irradiation on the hydride formation must be evaluated. We carried out ab-initio calculations of vacancy cluster and the segregation of hydrogen to the cluster to deduce the fundamental parameters for the modeling of hydride formation. The results are indispensable for the design of the new reactor.
Kim, Jae-Hwan; Nakano, Suguru; Akatsu, Yoshiaki; Nakamichi, Masaru
no journal, ,
no abstracts in English
Takase, Kazuyuki; Yoshida, Hiroyuki; Okada, Hidetoshi*; Koikari, Soji*; Tsuzuki, Nobuyoshi*
no journal, ,
no abstracts in English
Suzuki, Kenta; Isowa, Mitsuru; Kawabata, Kuniaki; Torii, Tatsuo
no journal, ,
no abstracts in English
Nagai, Haruyasu
no journal, ,
no abstracts in English
Tazawa, Yujiro; Nishihara, Kenji; Sugawara, Takanori; Tsujimoto, Kazufumi
no journal, ,
Transmutation Physics Experimental Facility (TEF-P) planned in the J-PARC project uses minor actinide (MA) fuels which have large radioactivity. So it is necessary to remote handling for loading and taking these MA fuel pins to the TEF-P core. The testing equipment for fuel loading was fabricated with dummy fuel pins and the mock-up core, and performed the loading and taking test. Useful design data was obtained by the fabrication, and it was confirmed to load/take dummy fuel pins from the mock-up core without failure.
Kato, Yasuaki; Yanagihara, Satoshi*; Iguchi, Yukihiro; Tezuka, Masashi; Koda, Yuya
no journal, ,
no abstracts in English
Nishida, Akemi; Iigaki, Kazuhiko; Sawa, Kazuhiro
no journal, ,
The objective of this research was to investigate the influence of differences between methods for evaluating the seismic response of the equipment and piping of a nuclear facility. For the input ground motion, one wave was chosen from among 200 waves of input ground motions of maximum acceleration of 700-1100 cm/s created for the Oarai District of the Ibaraki Prefecture. Seismic safety evaluations were performed using the conventional method, which relies on floor response spectrum data, the multi-input method, and the analytical method using a three-dimensional building model. The differences between the three methods were summarized. The target equipment and piping system were cooling systems in a model plant. It was found that the response predicted by the multi-input method and the analytical method using three-dimensional building model were approximately half of the response predicted by the conventional method.
Tsujimura, Norio; Yoshida, Tadayoshi; Takada, Chie
no journal, ,
no abstracts in English
Ishimi, Akihiro; Katsuyama, Kozo; Akasaka, Naoaki; Misawa, Susumu*
no journal, ,
no abstracts in English