A Systematic approach for the adequacy analysis of a set of experimental databases: Application in the framework of the ATRIUM activity

Baccou, J.*; Glantz, T.*; Ghione, A.*; Sargentini, L.*; Fillion, P.*; Damblin, G.*; Sueur, R.*; Iooss, B.*; Fang, J.*; Liu, J.*; et al.

Nuclear Engineering and Design, 421, p.113035_1 - 113035_16, 2024/05

https://doi.org/10.1016/j.nucengdes.2024.113035

Wettability of pure metals with liquid sodium and liquid tin

Saito, Junichi; Kobayashi, Yohei*; Shibutani, Hideo*

Materials Transactions, 62(10), p.1524 - 1532, 2021/10

https://doi.org/10.2320/matertrans.MT-M2021107

no abstracts in English

Wettability of pure metals with liquid sodium and liquid tin

Saito, Junichi; Kobayashi, Yohei*; Shibutani, Hideo*

Nihon Kinzoku Gakkai-Shi, 85(3), p.110 - 119, 2021/03

https://doi.org/10.2320/jinstmet.J2020042

The Deposition densities of radiocesium and the air dose rates in undisturbed fields around the Fukushima Dai-ichi Nuclear Power Plant; Their temporal changes for five years after the accident

Mikami, Satoshi; Tanaka, Hiroyuki*; Matsuda, Hideo*; Sato, Shoji*; Hoshide, Yoshifumi*; Okuda, Naotoshi*; Suzuki, Takeo*; Sakamoto, Ryuichi*; Ando, Masaki; Saito, Kimiaki

Journal of Environmental Radioactivity, 210, p.105941_1 - 105941_12, 2019/12

AA2019-0019.pdf:2.65MB

https://doi.org/10.1016/j.jenvrad.2019.03.017

The deposition densities of radiocesium and the air dose rates were repeatedly measured in a large number of undisturbed fields within the 80km zone that surrounds the Fukushima Dai-ichi Nuclear Power Plant site between 2011 and 2016, and features of their temporal changes were clarified. The average air dose rate excluding background radiation in this zone decreased to about 20% of the initial value during the period from June 2011 to August 2016, which was essentially a result of the radioactive decay of Cs with a half-life of 2.06y. The air dose rate reduction was faster than that expected from the decay of radiocesium by a factor of about two, with most of this reduction being attributed to the penetration of radiocesium into the soil. The average deposition densities of Cs and Cs in fields that were not decontaminated were found to have decreased nearly according to their expected radioactive decay, which indicated that the movement of radiocesium in the horizontal direction was relatively small. The effect of decontamination was apparently observed in the measurements of air dose rates and deposition densities. Nominally, the average air dose rates in the measurement locations were reduced by about 20% by decontamination and other human activities, of which accurate quantitative analysis is and continue to be a challenge.

Systematic effects on cross section data derived from reaction rates in reactor spectra and a re-analysis of Am reactor activation measurements

erovnik, G.*; Schillebeeckx, P.*; Becker, B.*; Fiorito, L.*; Harada, Hideo; Kopecky, S.*; Radulovic, V.*; Sano, Tadafumi*

Nuclear Instruments and Methods in Physics Research A, 877, p.300 - 313, 2018/01

https://doi.org/10.1016/j.nima.2017.09.064

Methodologies to derive cross section data from spectrum integrated reaction rates were studied. The Westcott convention and some of its approximations were considered. The accuracy of the results strongly depends on the assumptions that are made about the neutron energy distribution, which is mostly parameterised as a sum of a thermal and an epi-thermal component. Resonance integrals derived from such data can be strongly biased. When the energy dependence of the cross section is known and information about the neutron energy distribution is available, a method to correct for a bias on the cross section at thermal energy is proposed. Reactor activation measurements to determine the thermal Am(n, ) cross section reported in the literature were reviewed, where the results were corrected to account for possible biases. These data combined with results of time-of-flight measurements give a capture cross section 720 (14) b for Am(n, ) at thermal energy.

2016 Professional Engineer (PE) test preparation course "Nuclear and Radiation Technical Disciplines"

Takahashi, Naoki; Yoshinaka, Kazuyuki; Harada, Akio; Yamanaka, Atsushi; Ueno, Takashi; Kurihara, Ryoichi; Suzuki, Soju; Takamatsu, Misao; Maeda, Shigetaka; Iseki, Atsushi; et al.

Nihon Genshiryoku Gakkai Homu Peji (Internet), 64 Pages, 2016/00

no abstracts in English

Estimation of I-131 concentration using time history of pulse height distribution at monitoring post and detector response for radionuclide in plume

Hirayama, Hideo*; Kawasaki, Masatsugu; Matsumura, Hiroshi*; Okura, Takehisa; Namito, Yoshihito*; Sanami, Toshiya*; Taki, Mitsumasa; Oishi, Tetsuya; Yoshizawa, Michio

Nihon Genshiryoku Gakkai Wabun Rombunshi, 13(3), p.119 - 126, 2014/09

https://doi.org/10.3327/taesj.J14.006

A method of deducing the I-131 concentration in a radioactive plume from the time history of peak count rates determined from pulse height spectra obtained from an NaI(Tl)scintillation detector employed as a detector of a monitoring post was presented. The concentrations of I-131 in the plumes were estimated from the count rates using the calculated response of the NaI(Tl) detector with egs5 for a model of a plume uniformly containing I-131. This method was applied to the data from the monitoring posts at Nuclear Science Research Institutes of Japan Atomic Energy Agency (JAEA). The estimated time history variation of I-131 concentrations in plumes was in fair agreement with those measured directly by an air sampling method. The difference was less than a factor of 4 for plumes that arrived on March 15 and March 21, indicating relatively high I-131 concentrations among the plumes studied in this work.

Alpha-ray irradiation damage on diverse rubber materials applied to glove box for plutonium treatment

Saito, Kosuke; Nogami, Yoshitaka; Kodato, Kazuo; Matsuyama, Kazutomi; Endo, Hideo

JAEA-Research 2012-027, 118 Pages, 2012/09

JAEA-Research-2012-027.pdf:21.12MB

This report is compilation of 4 years tests and experiments of simulated alpha-ray irradiation on diverse materials for glove box application at Plutonium Fuel Development Center, Tokai, JAEA. Specimens prepared from the materials are irradiated with He ion beam whose kinetic energy was 5 MeV and sent to exterior observation, optical microscopy and tensile tests. Experiments revealed ion-irradiation generally makes tens of micrometers of deteriorated layer which is hardened and discolored on the surface of the specimens. According to dose, tensile properties such as tensile strength and elongation at break decrease generally. Tensile strength decrease is expected to ascribe to stress concentration on cracks of irradiation-damaged surface and rupture. Lead-contained glove, which is ordinarily used on highly -radiative environments, saturates the decrease of its tensile strength around fluence of 1.4e+14 cm. In addition, deterioration was accelerated for tension-loaded material and the saturation is around 4.6e+13 cm for 100%-extended specimens. The candidates of alternative new materials are two kinds of developed chlorosulfonated polyethylene (CSM) and conductive rubber, which were experimented and tested in like manner. From the results and inherent properties of these materials, one kind of CSM and conductive rubber are relatively promising. Gloves used at low-dose environments and vinyl chloride applied for glove ports were also experimented and tested, and quantitative data were which are useful for life-elongation measure obtained. The irradiation tests on this report are unprecedented ones with low-energy ion, and the obtained quantitative data of material properties and deterioration are scientifically rare and important.

Effect of specimen shape on the elongation of 316LN jacket used in the ITER toroidal field coil

Hamada, Kazuya; Kawano, Katsumi; Saito, Toru; Iguchi, Masahide; Nakajima, Hideo; Teshima, Osamu*; Matsuda, Hidemitsu*

AIP Conference Proceedings 1435, p.55 - 62, 2012/06

https://doi.org/10.1063/1.4712080

The TF coil conductor was composed of 900 NbSn superconducting strands and 522 Cu strands protected by circular sheath tube (jacket) with the outer diameter of 43.7 mm. The jacket section is a seamless tube made of modified 316LN. JAEA tested different types of tensile specimen (Japanese Industrial Standards (JIS) type and ASTM type) cut from jacket. ASTM type specimen has longer and wider reduced section than those of JIS type specimen. Elongation of as received condition is not dependent on specimen shape. But after cold work and aging, the elongation is deteriorated due to a sensitization and scattering of elongation is larger than that of as received condition. Fracture mode of aged jacket is "cup and cone fracture", which have a mixture of inter granular at center area and trans-granular factures in circumference area. It is considered that initiation of fracture is more sensitive on test specimen shape with low ductility.

Preparation for the ITER central solenoid conductor manufacturing

Hamada, Kazuya; Nunoya, Yoshihiko; Isono, Takaaki; Takahashi, Yoshikazu; Kawano, Katsumi; Saito, Toru; Oshikiri, Masayuki; Uno, Yasuhiro; Koizumi, Norikiyo; Nakajima, Hideo; et al.

IEEE Transactions on Applied Superconductivity, 22(3), p.4203404_1 - 4203404_4, 2012/06

https://doi.org/10.1109/TASC.2011.2176708

Japan Atomic Energy Agency (JAEA) has the responsibility for procurement of all of the ITER central solenoid (CS) conductor lengths. The CS conductor is composed of 576 Nb Sn superconducting strands and 288 Cu strands assembled together into a multistage cable and protected by a circle-in-square sheath tube (jacket) with the outer dimension of 49 mm. In preparation for CS conductor production, the following R&D activities have been performed; (1) Mechanical tests at 4 K have been performed for jacket candidate materials such as 316LN and JK2LB, (2) Welding test for filler selection, (3) Measurement of coefficient of sliding friction using a 100-m long dummy cable, (4) Deformation characteristics of the conductor cross section after compaction and spooling. As a result of these R&D, the CS conductor jacket manufacturing technologies have been confirmed to start the procurement of the CS conductor.