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Tsuchiya, Harufumi; Kitatani, Fumito; Kureta, Masatoshi; Maeda, Makoto
no journal, ,
no abstracts in English
Ozu, Akira; Maeda, Makoto; Komeda, Masao; Tobita, Hiroshi; Kureta, Masatoshi
no journal, ,
no abstracts in English
Tada, Kenichi; Nagaya, Yasunobu
no journal, ,
JAEA has been developing the nuclear data processing code FRENDY (FRom Evaluated Nuclear Data librarY to any application). In this presentation, construction of the probability table in the unresolved resonance region is described.
Kikuchi, Takeo; Tada, Kenichi; Suyama, Kenya
no journal, ,
To estimate the prediction accuracy of the integrated burn up analysis code system SWAT4, we compared the calculation results of SWAT4 and the PIE data of the BWR fuel which was measured by JAERI in 1990s. Comparison results are indicated that the C/E value of major heavy nuclei, e.g., U and Pu, is approximately 1.0. The calculation results are also indicated that some fission products, e.g., Sm, have the larger difference.
Zaima, Naoki; Naganuma, Masaki; Sakao, Ryota
no journal, ,
no abstracts in English
Iwai, Yasunori; Kondo, Akiko*; Edao, Yuki; Sato, Katsumi; Kubo, Hitoshi*; Oshima, Yusuke*
no journal, ,
Effect of halogenated gas on detritiation efficiency of the detritiation system has been investigated taking an event of off normal event such as fire into consideration. Concerning the activity of platinum catalyst for oxidation of tritium, we have evaluated the steep decrease in activity of platinum catalyst in the presence of halogenated gas. In order to avoid the steep decrease in activity, a noble catalyst alloyed with platinum and palladium showed an outstanding proof. In addition, the halogenated acid produced over catalyst surface affects the activity of catalyst. As for water absorber, a molecular sieve decreased its water absorbing capacity in the presence of halogenated gas.
Furutachi, Naoya; Minato, Futoshi; Iwamoto, Osamu
no journal, ,
To establish the nuclear transmutation system for the long-lived fission products (LLFPs), it is desired to improve precision of the simulation calculation for the transmutation system. To achieve this, nuclear data of various nuclei produced via the nuclear transmutation of LLFPs are also important. However, it is expected that unstable nuclei with no available experimental data are produced via the nuclear transmutation. One of the physical quantity that is very difficult to predict with no experimental data is the thermal neutron capture cross section. The thermal neutron capture cross section is dominated by the energy and width of the first resonance, and slight variation of them can change the thermal neutron capture cross section drastically. While it is very difficult to determine them with high precision, it is known that a resonance width follows Porter-Thomas distribution because of complexity and randomness of a nuclear structure, and a resonance spacing follows Wigner distribution. In this work, we calculate the thermal neutron capture cross section by using the statistical property of the resonance parameters with Monte Carlo method. The calculation result is obtained as a probability distribution of the thermal neutron capture cross section. We calculated approximately 250 nuclei that have experimental data, and found that the dispersion of the experimental data is well explained by the calculated probability distribution.
Minato, Futoshi
no journal, ,
no abstracts in English
Kureta, Masatoshi; Koizumi, Mitsuo; Ozu, Akira; Tsuchiya, Harufumi; Seya, Michio
no journal, ,
The new program "Development of active neutron NDA techniques" has been started for non-proliferation applications collaborating with EC-JRC. The final purpose of this program is to establish the measurement techniques for the high radioactive special nuclear material such as MA-Pu fuel for transmutation of minor actinide. In this program, JAEA will conduct the R&D on active neutron non-destructive measurement techniques, DDA, NRTA, PGA/NRCA and DGS. The research and development plan is presented in this report.
Komeda, Masao; Maeda, Makoto; Shimofusa, Taichi; Tobita, Hiroshi; Ozu, Akira; Kureta, Masatoshi
no journal, ,
He-3 detectors are most popular for NDA systems of the active neutron method. However, the price of He-3 detectors is rising due to short supply of the He-3 gas, and it is concerned that the cost of fabricating a NDA system with many He-3 detectors is rising. A new hybrid detector called B-10 plus detector has been developed by GE Reuter-Stokes. The B-10 plus detector has higher detection efficiency than a B-10 detector while the usage of He-3 gas is reduced. We make a report on experimental results of performance comparison between He-3 detectors and B-10 plus detectors on the active neutron method.
Tsukimori, Kazuyuki; Ando, Masanori; Yada, Hiroki; Anoda, Yoshinari*; Ichimiya, Masakazu*; Uno, Masayoshi*
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
Nagaya, Yasunobu
no journal, ,
no abstracts in English