Development of "MOX weighing and Ball-mill blending" based on experience in operation and maintenance of MOX fuel manufacturing equipment

Kawasaki, Kohei; Ono, Takanori; Shibanuma, Kimikazu; Goto, Kenta; Aita, Takahiro; Okamoto, Naritoshi; Shinada, Kenta; Ichige, Hidekazu; Takase, Tatsuya; Osaka, Yuki; et al.

JAEA-Technology 2022-031, 91 Pages, 2023/02

JAEA-Technology-2022-031.pdf:6.57MB

The document for back-end policy opened to the public in 2018 by Japan Atomic Energy Agency (hereafter, JAEA) states the decommissioning of facilities of Nuclear Fuel Cycle Engineering Laboratories and JAEA have started gathering up nuclear fuel material of the facilities into Plutonium Fuel Production Facilities (hereafter, PFPF) in order to put it long-term, stable and safe storage. Because we planned to manufacture scrap assemblies almost same with Monju fuel assembly using unsealed plutonium-uranium mixed-oxide (hereafter, MOX) powder held in PFPF and transfer them to storage facilities as part of this "concentration" task of nuclear fuel material, we obtained permission to change the use of nuclear fuel material in response to the new regulatory Requirements in Japan for that. The amount of plutonium (which is neither sintered pellets nor in a lidded powder-transport container) that could be handled in the pellet-manufacturing process was limited to 50 kg Pu or less in order to decrease the facility risk in this manufacture. Therefore, we developed and installed the "MOX weighing and blending equipment" corresponding with small batch sizes that functioned in a starting process and the equipment would decrease handling amounts of plutonium on its downstream processes. The failure data based on our operation and maintenance experiences of MOX fuel production facilities was reflected in the design of the equipment to further improve reliability and maintainability in this development. The completed equipment started its operation using MOX powder in February 2022 and the design has been validated through this half-a-year operation. This report organizes the knowledge obtained through the development of the equipment, the evaluation of the design based on the half-a-year operation results and the issues in future equipment development.

Stabilization treatment of nuclear fuel material contained with organic matter

Senzaki, Tatsuya; Arai, Yoichi; Yano, Kimihiko; Sato, Daisuke; Tada, Kohei; Ogi, Hiromichi*; Kawanobe, Takayuki*; Ono, Shimpei; Nakamura, Masahiro; Kitawaki, Shinichi; et al.

JAEA-Testing 2022-001, 28 Pages, 2022/05

JAEA-Testing-2022-001.pdf:2.33MB

In preparation for the decommissioning of Laboratory B of the Nuclear Fuel Cycle Engineering Laboratory, the nuclear fuel material that had been stored in the glove box for a long time was moved to the Chemical Processing Facility (CPF). This nuclear fuel material was stored with sealed by a polyvinyl chloride (PVC) bag in the storage. Since it was confirmed that the PVC bag swelled during storage, it seems that any gas was generated by radiolysis of the some components contained in the nuclear fuel material. In order to avoid breakage of the PVC bag and keep it safety for long time, we began the study on the stabilization treatment of the nuclear fuel material. First, in order to clarify the properties of nuclear fuel material, radioactivity analysis, component analysis, and thermal analysis were carried out. From the results of thermal analysis, the existence of organic matter was clarified. Then, ion exchange resin with similar thermal characteristics was selected and the thermal decomposition conditions were investigated. From the results of these analyzes and examinations, the conditions for thermal decomposition of the nuclear fuel material contained with organic matter was established. Performing a heat treatment of a small amount of nuclear fuel material in order to confirm the safety, after which the treatment amount was scaled up. It was confirmed by the weight change after the heat treatment that the nuclear fuel material contained with organic matter was completely decomposed.

Stress partitioning behavior of duplex alloys consisting of BCC and FCC phases at low temperature

Yamashita, Takayuki; Tomono, Shohei*; Morooka, Satoshi; Harjo, S.; Kawasaki, Takuro; Nameki, Tatsuya*; Koga, Norimitsu*; Umezawa, Osamu*

JPS Conference Proceedings (Internet), 33, p.011064_1 - 011064_6, 2021/03

https://doi.org/10.7566/JPSCP.33.011064

Nonhomologous end-joining repair plays a more important role than homologous recombination repair in defining radiosensitivity after exposure to high-LET radiation

Takahashi, Akihisa*; Kubo, Makoto*; Ma, H.*; Nakagawa, Akiko*; Yoshida, Yukari*; Isono, Mayu*; Kanai, Tatsuaki*; Ono, Tatsuya*; Furusawa, Yoshiya*; Funayama, Tomoo; et al.

Radiation Research, 182(3), p.338 - 344, 2014/09

https://doi.org/10.1667/RR13782.1

To clarify whether high-LET radiation inhibits all repair pathways or specifically one repair pathway, studies were designed to examine the effects of radiation with different LET values on DNA DSB repair and radiosensitivity. Embryonic fibroblasts bearing repair gene KO were exposed to X rays, carbon-, iron-, neon- and argon-ion beams. Cell survival was measured with colony-forming assays. The sensitization enhancement ratio (SER) values were calculated using the 10% survival dose of wild-type cells and repair-deficient cells. Cellular radiosensitivity was listed in descending order: double-KO cells NHEJ-KO cells HR-KO cells wild-type cells. Although HR-KO cells had an almost constant SER value, NHEJ-KO cells showed a high-SER value when compared to HR-KO cells, even with increasing LET values. These results suggest that with carbon-ion therapy, targeting NHEJ repair yields higher radiosensitivity than targeting homologous recombination repair.

Increase in cell motility by carbon ion irradiation via the Rho signaling pathway and its inhibition by the ROCK inhibitor Y-27632 in lung adenocarcinoma A549 cells

Murata, Kazutoshi*; Noda, Shinei*; Oike, Takahiro*; Takahashi, Akihisa*; Yoshida, Yukari*; Suzuki, Yoshiyuki*; Ono, Tatsuya*; Funayama, Tomoo; Kobayashi, Yasuhiko; Takahashi, Takeo*; et al.

Journal of Radiation Research, 55(4), p.658 - 664, 2014/07

https://doi.org/10.1093/jrr/rru002

The effect of carbon ion irradiation on cell motility through the Rho signaling pathway in the human lung adenocarcinoma cell line A549 was studied. At 48 h after irradiation, the cell motility of A549 cells became significantly greater, and the formation of protrusions significantly increased in cells irradiated with carbon ion. The observed increase in cell motility due to carbon ion irradiation was similar to that observed due to X-ray irradiation. Western-blot analysis showed that carbon ion irradiation increased P-MLC2-S19 expression compared with in unirradiated controls, while total MLC2 expression was unchanged. Exposure to a non-toxic concentration of Y-27632, a specific inhibitor of ROCK, reduced the expression of P-MLC2-S19 after C-ion irradiation, resulting in a significant reduction in migration. These data suggest that carbon irradiation increases cell motility in A549 cells via the Rho signaling pathway and that ROCK inhibition reduces that effect.

Identified charged hadron production in collisions at = 200 and 62.4 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06

https://doi.org/10.1103/PhysRevC.83.064903

Transverse momentum distributions and yields for , and in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as and scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.

Radiation-induced ICAM-1 expression via TGF-1 pathway on human umbilical vein endothelial cells; Comparison between X-ray and carbon-ion beam irradiation

Kiyohara, Hiroki*; Ishizaki, Yasuki*; Suzuki, Yoshiyuki*; Kato, Hiroyuki*; Hamada, Nobuyuki*; Ono, Tatsuya*; Takahashi, Takeo*; Kobayashi, Yasuhiko; Nakano, Takashi*

Journal of Radiation Research, 52(3), p.287 - 292, 2011/03

https://doi.org/10.1269/jrr.10061

(), a novel hypernodulation mutant of affected in vascular tissue organization and floral induction

Kira, Erika*; Tateno, Kumiko*; Miura, Kinichiro*; Haga, Tatsuya*; Hayashi, Masaki*; Harada, Kyuya*; Sato, Shusei*; Tabata, Satoshi*; Shikazono, Naoya; Tanaka, Atsushi; et al.

Plant Journal, 44(3), p.505 - 515, 2005/11

https://doi.org/10.1111/j.1365-313X.2005.02543.x

no abstracts in English

Cryogenic neutron detector by InSb semiconductor detector with high-density helium-3 gas converter

Nakamura, Tatsuya; Katagiri, Masaki; Aratono, Yasuyuki; Kanno, Ikuo*; Hishiki, Shigeomi*; Sugiura, Osamu*; Murase, Yasuhiro*

Nuclear Instruments and Methods in Physics Research A, 520(1-3), p.76 - 79, 2004/03

https://doi.org/10.1016/j.nima.2003.11.225

The neutron-detection characteristics of a cryogenic neutron detector comprising an InSb semiconductor detector and a helium-3 gas converter were evaluated at a gas pressure of up to 12.5atm at 4.2K. The detector successfully detected stable neutrons under these conditions, where the density of the helium-3 gas is a few-hundred times higher than that at room temperature. It was found that the neutron detection efficiency was correlated with the gas pressure - even in a backward-detection configuration - in low-temperature, high-pressure helium-3.

Development of Quality Assurance System for Resistance Welding by Ultrasonic Examination -Fabrication of STB for Resistance Welding and Ultrasonic Examination-

Kono, Shusaku; Seki, Masayuki; Fujio, Ishibashi,; Hirako, Kazuhiko*; Tsukada, Tatsuya*

JNC TN8430 2003-010, 28 Pages, 2003/07

JNC-TN8430-2003-010.pdf:2.18MB

The defect occurred at the resistance welding zone is very minute and therefore cannot be identified by X-ray inspection. Then, the ultrasonic examination method, in which the resolution of the defect is higher than that of the X-ray inspection method, has been developed. The ultrasonic wave sounds straight easier in the material than X rays, excels in defecting the micro defect. However, the pulse amplitude of ultrasonic wave is influenced by the shape and direction of the defect. Then, the ultrasonic inspection equipement, in which the ultrasonic probe and the sample rotation axis are controlled to drive with the pulse motor and the defect data (position and size)are analized by image processing ultrasonic signal, was developed to measure the shape and the position of defect accurately. However, an ultrasonic examination method is the comparative inspection method. Therefore, the standard test block or the reference block is indispensable to guarantee the defectability and the ultrasonic echo sensibility of the inspection device. The standard test block is provided in JIS etc, it is needed to defect the peculiar defect occurred at the resistance welding zone. Then, the method of processing a standard test block is examined, the standard test block was made experimentally by electric discharge processing and diffusion junction method. The ultrasonic echo sensitivity and the threshold for image processing were proofread by using the standard test block, the ultrasonic inspection and metallographic inspection were executed. Comparing the ultrasonic inspection results with the metallographic inspection results, the detectability of defect depth and the measurement accuracy were proved to be 3m and with errors less than 10m respectively. From these results, the effectireness of proofreading the ultrasonic inspection condition by the standard test block was confirmed. Moreover, it was confirmed that there was a peculiar relationship between the depth ...