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-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.
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
Imaizumi, Yuya; Fukano, Yoshitaka
no journal, ,
The test result of EFM1 in the CABRI in-pile experiment which was conducted as an internationally collaborated project was analyzed by SAS4A code. The code was developed for the analysis of initiation phase of core disruptive accident. In the EFM1 test, transient overpower was imposed after the cladding melting and coolant boiling which was due to the previously imposed loss of flow. The behavior of large relocation and refreezing of the molten fuel which was caused by the heating peak after the fuel melting was one of the important point in the analysis. As a result, good agreements were observed between the results of experiment and analysis such as timings of coolant boiling, extension of boiling area and behavior of molten fuel motion.
Satoh, Daiki; Iwamoto, Yosuke; Ogawa, Tatsuhiko
no journal, ,
Many neutrons are produced in forward directions by intermediate-energy proton-induced reactions. While it is known that collective motion in a target nucleus plays important role in this neutron production, validity of theoretical model and nuclear-data library has not been examined well due to a lack of experimental data. Hence, we obtained systematic data of neutron-production double-differential cross section in the most-forward direction. The experiment was performed at TIARA of Takasaki Advanced Radiation Research Institute, JAEA. 48-, 63-, and 78-MeV proton beams were bombarded upon thin lithium, carbon, aluminum, iron, and lead target, and the neutrons produced in the most-forward direction were led to experimental room passing through a collimator. Scintillation detectors were used to the neutron detection. The measured data for lighter nuclei such as Li, C, Al showed peak structures corresponding to energy levels of the nuclei. In the spectra for Pb, one can see a broad peak caused by the collective motion of the nucleus. In comparison with the calculation results of PHITS using a theoretical model INCL and a nuclear-data library JENDL-4.0/HE, it was found that the JENDL-4.0/HE reproduces the measure spectra better than the INCL does.
Suzuki, Hideya; Tsubata, Yasuhiro; Shibata, Mitsunobu; Kurosawa, Tatsuya; Kawasaki, Tomohiro; Sagawa, Hiroshi; Matsumura, Tatsuro
no journal, ,
JAEA continues to carry out the development of the ADS(Double-strata). Mutual separation of Am(III) and Cm(III) is important for the development of the partitioning process. The separation is particularly difficult, because they have the analogous chemical behavior. Alkyl diamide amine (ADAAM), a new high-performance reagent with a simple structure, was examined for the mutual separation of Am(III) and Cu(III). The combination of ADAAM and N,N,N',N'-tetraethyldiglycolamide (TEDGA) as a masking agent shows selectivity for Am(III) over Cm(III) in highly acidic media with separation factors up to 41.
Hoshi, Takahiro; Nagaoka, Shinichi; Kudo, Atsunari; Ouchi, Masayuki; Isobe, Hiroyasu; Obu, Tomoyuki; Kurabayashi, Kazuaki
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.
Ota, Yoshimi*; Nishida, Akemi; Tsubota, Haruji
no journal, ,
Many empirical formulas have been proposed for evaluating the local damage to reinforced concrete structures caused by rigid missile impact. Most of these formulas have been derived based on impact tests perpendicular to target structures and up to now few impact tests oblique to target structures has been carried out. Therefore, the purpose of this study is to propose a new formula for evaluating the local damage caused by oblique impact based on past experimental results. A new formula is derived by modifying a past empirical formula of normal impact and the conformity of the formula to the results of past oblique impact tests is discussed.
Shibamoto, Yasuteru; Abe, Satoshi; Ishigaki, Masahiro; Yonomoto, Taisuke
no journal, ,
no abstracts in English
Ioka, Ikuo; Kato, Hitoshi; Ogawa, Hiroaki; Osaka, Masahiko
no journal, ,
When the function of cooling system for a spent fuel pool loses, the spent fuel pin put under vapor environment. The helium gas at the time of making and the FP gas are enclosed in the spent fuel pin. The spent fuel pin with internal pressure is oxidized during severe accident. The effect of internal pressure on oxidation behavior of Zircaloy-2 was investigated. The oxidation test was carried out at 600C in steam atmosphere. The length of Zircaloy-2 specimen is 500 mm, and heated zone is 200 mm. The amount of hydrogen gas was measured during the test, and the oxide film was analyzed. The amount of hydrogen gas decreased to about 70 ppm after increasing rapidly in early stages of the test. The thickness of oxide film decreased with increasing the internal pressure. It is confirmed that internal pressure affected in the oxidation behavior of Zircaloy-2 in this test condition.
Hashimoto, Shintaro; Iwamoto, Osamu; Sato, Tatsuhiko; Niita, Koji*
no journal, ,
PHITS has been used for many purposes such as radiation shielding in accelerator facilities. The PHITS result involves not only statistical error related to the number of trials in the Monte Carlo method but also systematic error attributed to uncertainty of nuclear data and nuclear reaction model. We developed a method to estimate the influence of covariance of JENDL on the PHITS result. In this method, we change the cross section within the covariance, and execute PHITS using each cross section. The result depends on the cross section. We regard its variance as the systematic error. PHITS can give both the statistical and systematic errors. We can discuss the reliability of the result of the radiation shielding. This method is applied to estimate the systematic error of neutron flux in neutron shielding calculations. The systematic error of the calculated flux depends on the depth in shielding material due to the number of scattering.
Kudo, Atsunari; Yanagibashi, Futoshi; Tada, Kazuhito; Hoshi, Takahiro; Fujimoto, Ikuo; Obu, Tomoyuki
no journal, ,
no abstracts in English
Yokoyama, Kenji; Yamamoto, Akio*
no journal, ,
no abstracts in English