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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
Nakayama, Shinsuke; Kono, Hiroshi*; Araki, Shohei*; Watanabe, Yukinobu*; Iwamoto, Osamu; Ye, T.*
no journal, ,
Theoretical model analysis of deuteron-induced activation cross sections were performed using the calculation code system we have developed so far. In our previous works, we analyzed mainly double differential cross sections for the 
and 
reactions, and activation cross sections from the 
reactions in order to validate calculation method for the direct processes. In the present work, we analyzed activation cross sections from multi particle emission induced by high energy deuteron in order to validate calculation method for statistical decay processes. In the result of analysis, it was found out the calculation method adopted in our code system is valid.
Utsuno, Yutaka; Yoshida, Sota*; Shimizu, Noritaka*; Otsuka, Takaharu*
no journal, ,
no abstracts in English
Sawamura, Masaru; Umemori, Kensei*; Sakai, Hiroshi*; Furuya, Takaaki*; Enami, Kazuhiro*; Egi, Masato*
no journal, ,
no abstracts in English
Tsuji, Tomoyuki; Sakamoto, Yoshiaki; Hoshino, Yuzuru; Suzuki, Yasuo*; Machida, Hiroshi*
no journal, ,
JAEA is planning a business for the disposal of low level radioactive wastes generated from research, industrial, and medical facilities. Because those wastes are generated from various facilities, it is important to develop reasonable confirmation methods based on the characteristics of radioactive wastes. As a model case of development of the evaluation method to determine the radioactivity concentration, the common method was studied to determine the radioactivity concentration of PIE wastes stored in NDC. The radioactivity concentrations of 17 nuclides (Sr-90, Tc-99, U-235, 238, Pu-238, 239+240, 241, Am-241, Cm-244 and so on) were calculated by ORIGEN-2 based on actual data such as initial contents and operation record of the spent fuel. From the comparison of the obtained data by radiological measurement with calculated values, it was studied that the theoretical method was applied to determine the radioactivity concentrations of 17 nuclides of PIE wastes.
Eguchi, Yuta; Sugawara, Takanori; Nishihara, Kenji; Tazawa, Yujiro; Tsujimoto, Kazufumi
no journal, ,
Transmutation Physics Experimental Facility (TEF-P) planned in the J-PARC project uses minor actinide (MA) fuel which has large decay heat. So it is necessary to consider the increase of the core temperature when the core cooling system is stopped. This change of the core temperature was evaluated by thermal conduction analysis. It was found that the impact of thermal insulation in the empty rectangular lattice matrix area was large. Testing equipment was fabricated to verify the accuracy of calculation model for the empty lattice matrix which was the free convection model of sealed fluid. By using this equipment, thermal distribution and one dimensional heat flow through the lattice were measured. It was observed that the actual equivalent thermal conductivity in the lattice was larger than the free convection model. It was also confirmed that the insertion of the aluminum block into the empty lattice could achieve the higher equivalent thermal conductivity. These results could be the useful data for the thermal conduction analysis.
Arai, Masaji; Takino, Kazuo
no journal, ,
The Department of Research Reactor and Tandem Accelerator began to discuss basic design concept of the new multipurpose research reactor succeeding to JRR-3.
Yamano, Hidemasa; Kawasaki, Nobuchika; Kubo, Shigenobu
no journal, ,
Tentative external hazard conditions assumed for a next-generation SFR design in 2011 were not reasonable because of an envelope range covering severe conditions. This report proposed a reasonable definition method of external hazard conditions and defined specific design basis and design extension conditions against various external hazards.
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.
Kadowaki, Masanao; Terada, Hiroaki; Katata, Genki; Furuno, Akiko; Nagai, Haruyasu
no journal, ,
In case of a nuclear accident or radiological emergency, a simulation with numerical models is a powerful means in order to predict distributions of the polluted air. Although a particle model that WSPEEDI has introduced shows advantage in the synoptic scale, it costs computationally because of the large amount of airborne particles. Moreover, the model has problems with uncertainties in the calculations on long range, due to exponentially increasing errors. For the reason, in this study the atmospheric transport modeling with a finite difference method: GEARN-FDM is proposed in order to improve WSPEEDI. The advection and diffusion in the atmosphere were calculated by using a mass conservative and monotonic manner scheme (Walcek, 2000) and Crank-Nicolson method, respectively. The distributions of tracer were good agreement with the first ETEX measurements. In this session the validation and comparison will be discussed.
Sato, Kaoru; Takahashi, Fumiaki
no journal, ,
Organ doses, which are basis of dose assessment in radiation protection, are derived from ICRP reference phantoms (Male: RCP-AM, Female: RCP-AF) with body physiques of standard Caucasian. In adult, Japanese body physiques are smaller than those of Caucasian. To study impact of application of organ doses of RCP-AM and RCP-AF to dose assessment of adult Japanese, we constructed Japanese male (JM-103) and female (JF-103) phantoms with body physiques of average adult Japanese. In addition, body physiques of adult Japanese have also wide distribution. Therefore, we newly constructed DJM (Male) and DJF (Female) with 8 body physiques by changing bust, chest, waist and hip of JM-103 and JF-103. Organ doses due to external photon irradiation of DJM and DJF were calculated, and were compared with those of RCP-AM and RCP-AF. In ISO geometry at 0.3 MeV and ROT geometry at 0.6 MeV, it was found that colon doses of DJM and DJF with body physiques, which are applicable to most adult Japanese, agreed with those of RCP-AM and RCP-AF within 10 %.
Sasaki, Yuji; Tsubata, Yasuhiro; Shirasu, Noriko; Shimazaki, Shoma*
no journal, ,
no abstracts in English
Sugawara, Takanori; Nishihara, Kenji; Tazawa, Yujiro; Tsujimoto, Kazufumi
no journal, ,
This presentation shows fabrication and test results of a testing facility for fuel cooling that is a component of the testing facility for remote-handling of highly-radioactive MA fuels in the transmutation physics experimental facility (TEF-P) planned in the J-PARC. Evaluation formula of pressure drop and temperature increase used in the design of TEF-P was validated by the test, and, feasibility of cooling concept was confirmed.