Chemical species of cesium and iodine in condensed vaporized microparticles formed by melting nuclear fuel components with concrete materials

Onuki, Toshihiko*; Ye, J.*; Kato, Tomoaki; Liu, J.; Takano, Masahide; Kozai, Naofumi; Utsunomiya, Satoshi*

Environmental Science; Processes & Impacts, 25(7), p.1204 - 1212, 2023/07

https://doi.org/10.1039/D3EM00074E

To elucidate chemical forms of Cs and I in microparticles produced via the Fukushima Daiichi Nuclear Power Plant accident and released into the atmosphere, we analyzed Cs and I in condensed vaporized particles (CVP) produced by melting experiments using nuclear fuel components containing CsI with concrete. CVPs consisted of many round particles containing Cs and I of diameters less than several tens of micrometers. Two kinds of particles were present: one containing large amounts of Cs and I, suggesting the presence of CsI, and the other containing small amounts of Cs and I with large Si contents. Most of CsI from both particles were dissolved in water. On the contrary, some fractions of Cs remained from the latter particles. These results suggest that Cs was incorporated in CVPs along with Si to form water low-soluble CVPs

Evaporation of ruthenium from simulated fission-produced alloy precipitates in a nuclear fuel

Liu, J.; Miyahara, Naoya; Miwa, Shuhei; Takano, Masahide; Hidaka, Akihide; Osaka, Masahiko

Journal of Nuclear Materials, 527, p.151819_1 - 151819_7, 2019/12

https://doi.org/10.1016/j.jnucmat.2019.151819

To evaluate the effect of each constituent element on the evaporation rate of ruthenium (Ru) from fission-produced alloy precipitates, the oxidation and evaporation behaviors of metallic Ru, molybdenum (Mo), palladium (Pd), rhodium (Rh) and Mo-Ru-Pd-Rh alloy powders were investigated by thermogravimetric analysis under oxidizing atmospheres from 1473 to 1723 K. The findings led to the following conclusions: (1) The quick oxidation of Mo into condensed Mo oxides can effectively suppress the oxidation and evaporation of Ru in alloy powders; (2) After the complete evaporation of Mo, the evaporation loss rate of Ru would be directly influenced by the Ru activity in the Ru-Pd-Rh alloys, which is determined by the composition of alloys.

Magnetocaloric effect of Sr-substituted BaFeO in the liquid nitrogen and natural gas temperature regions

Yoshii, Kenji; Hayashi, Naoaki*; Mizumaki, Masaichiro*; Takano, Mikio*

AIP Advances (Internet), 7(4), p.045117_1 - 045117_6, 2017/04

https://doi.org/10.1063/1.4982244

We have investigated the magnetocaloric effect (MCE) of BaSrFeO (x0.2), a series of cubic perovskites showing a field-induced transition from helical antiferromagnetism to ferromagnetism. The maximum magnetic entropy change (-S) at 50 kOe varies from 5.8 J kgK (x=0) to 4.9 J kgK (x=0.2), while the refrigerant capacity remains almost the same at 165 J kg. Interestingly, the temperature of -S decreases from 116 K to 77 K with increasing x, providing this series of rare-earth-free oxides with potential as a magnetic refrigerant for the liquefaction of nitrogen and natural gas.

Suppression of temperature hysteresis in negative thermal expansion compound BiNiFeO and zero-thermal expansion composite

Nabetani, Koichiro*; Muramatsu, Yuya*; Oka, Kengo*; Nakano, Kiho*; Hojo, Hajime*; Mizumaki, Masaichiro*; Agui, Akane; Higo, Yuji*; Hayashi, Naoaki*; Takano, Mikio*; et al.

Applied Physics Letters, 106(6), p.061912_1 - 061912_5, 2015/02

https://doi.org/10.1063/1.4908258

Negative thermal expansion (NTE) of BiNiFeO is investigated by dilatometric curves, synchrotron X-ray diffraction, and X-ray absorption spectroscopy. All samples (x=0.05-0.15) shows large NTE with the coefficient of linear thermal expansion which induced by charge transfer between Bi and Ni in the controlled temperature range near room temperature. Compared with BiLnNiO (Ln: rare-earth elements), the thermal hysteresis that causes a problem for practical application is suppressed because random distribution of Fe in the Ni site changes the first order transition to second order-like transition.

Isolation of a novel UVB-tolerant rice mutant obtained by exposure to carbon-ion beams

Takano, Nao*; Takahashi, Yuko*; Yamamoto, Mitsuru*; Teranishi, Mika*; Yamaguchi, Hiroko*; Sakamoto, Ayako; Hase, Yoshihiro; Fujisawa, Hiroko*; Wu, J.*; Matsumoto, Takashi*; et al.

Journal of Radiation Research, 54(4), p.637 - 648, 2013/07

https://doi.org/10.1093/jrr/rrt007

Beam based alignment of synchrotron under coupled quadrupole magnet environment

Hayashi, Naoki; Hatakeyama, Shuichiro; Harada, Hiroyuki; Hotchi, Hideaki; Takano, Jumpei*; Tejima, Masaki*; Toyama, Takeshi*

Proceedings of 46th ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams (HB 2010) (Internet), p.57 - 61, 2010/09

http://accelconf.web.cern.ch/AccelConf/HB2010/papers/mopd08.pdf

The Beam Based Alignment (BBA) of the BPM is inevitable for precise and absolute beam position measurements. Even though careful fabrication and installation of the BPM detector, it has to be calibrated by using the beam. Usually, it requires that the individual quadrupole magnet is able to be controlled. However, it is not always that case. In addition, scanning over the all BPM is time consuming procedure. The BBA method under coupled QM environment would help to reduce time for calibration. It presents general formula and experiences at J-PARC RCS and parts of results are compared with the ordinal method at J-PARC MR.

Performance of the main ring BPM during the beam commissioning at J-PARC

Toyama, Takeshi*; Arakawa, Dai*; Hiramatsu, Shigenori*; Igarashi, Susumu*; Lee, S.*; Matsumoto, Hiroshi*; Odagiri, Junichi*; Tejima, Masaki*; Tobiyama, Makoto*; Hashimoto, Yoshinori*; et al.

Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.981 - 983, 2010/05

http://accelconf.web.cern.ch/AccelConf/IPAC10/papers/mope012.pdf

Experiences of operating BPM's during beam commissioning at the J-PARC MR are reported. The subjects are: (1) bug report, statistics and especially the effect of a beam duct step, (2) position resolution estimation (30 micrometers with 1 sec averaging), (3) beam based alignment.

Covariances of resonance self-shielding factor and its temperature gradient for uncertainty evaluation of Doppler reactivity

Zukeran, Atsushi*; Chiba, Go; Otsuka, Naohiko*; Ishikawa, Makoto; Takano, Hideki*

JAEA-Research 2008-091, 162 Pages, 2009/02

JAEA-Research-2008-091-01.pdf:5.8MB
JAEA-Research-2008-091-02.pdf:45.78MB

Uncertainty of Doppler reactivity is theoretically formulated and then uncertainties of self-shielding factor and its temperature gradient due to errors of resonance parameters were evaluated from NJOY output. Sensitivity analysis was made for U, U, Pu and Pu of JENDL-3.3 based on JFS-3 70 group structure. Resultant sensitivity coefficients are provided for the uncertainty evaluation of Doppler reactivity.

Covariance analyses of self-shielding factor and its temperature gradient for uranium-238 neutron capture reaction

Otsuka, Naohiko; Zukeran, Atsushi*; Takano, Hideki*; Chiba, Go; Ishikawa, Makoto

Journal of Nuclear Science and Technology, 45(3), p.195 - 210, 2008/03

https://doi.org/10.3327/jnst.45.195

Covariances of the self-shielding factor and its temperature gradient for the uranium-238 neutron capture reaction have been evaluated from the resonance parameter covariance matrix and sensitivity of the self-shielding factor and its temperature gradient to microscopic nuclear data. The resonance parameters and their covariance matrix for uranium-238 were taken from JENDL-3.3, while the sensitivity coefficients were calculated by varying resonance parameters and temperature. A set of computer code modules has been developed for calculation of the sensitivity coefficients at numerous resonance levels. The present result shows that the correlation among resonance parameters yields a substantial contribution to the variances of the self-shielding factor and its temperature gradient. In addition to the variances of these quantities, their correlation matrices in the JFS-3 70 group structure are also obtained.

Tomonaga-Luttinger liquid in a quasi-one-dimensional = 1 antiferromagnet observed by specific heat measurements

Hagiwara, Masayuki*; Tsujii, Hiroyuki*; Rotundu, C. R.*; Andraka, B.*; Takano, Yasumasa*; Tateiwa, Naoyuki; Kobayashi, Tatsuo*; Suzuki, Takafumi*; Suga, Seiichiro*

Physical Review Letters, 96(14), p.147203_1 - 147203_4, 2006/04

https://doi.org/10.1103/PhysRevLett.96.147203

Specific-heat experiments on single crystals of the = 1 quasi-one-dimensional bond-alternating antiferromagnet Ni(CHN)(NO)(ClO) (NTENP) have been performed in magnetic fields applied both parallel and perpendicular to the spin chains. We have found for the parallel field configuration that the magnetic specific heat () is proportional to temperature () above a critical field , at which the energy gap vanishes, in a temperature region above that of the long-range ordered state. The ratio = increases as the magnetic field approaches from above. The data are in good quantitative agreement with the prediction of the =1 conformal field theory in conjunction with the velocity of the excitations calculated by a numerical diagonalization, providing conclusive evidence for a Tomonaga-Luttinger liquid.