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.

Simultaneous measurement of neutron-induced fission and capture cross sections for Am at neutron energies below fission threshold

Hirose, Kentaro; Nishio, Katsuhisa; Makii, Hiroyuki; Nishinaka, Ichiro*; Ota, Shuya*; Nagayama, Tatsuro*; Tamura, Nobuyuki*; Goto, Shinichi*; Andreyev, A. N.; Vermeulen, M. J.; et al.

Nuclear Instruments and Methods in Physics Research A, 856, p.133 - 138, 2017/06

https://doi.org/10.1016/j.nima.2016.12.021

Sagittal focusing of synchrotron radiation X-rays using a winged crystal

Nisawa, Atsushi*; Yoneda, Yasuhiro; Ueno, Go*; Murakami, Hironori*; Okajima, Yuka*; Yamamoto, Kenichiro*; Semba, Yasunori*; Uesugi, Kentaro*; Tanaka, Yoshihito*; Yamamoto, Masaki*; et al.

Journal of Synchrotron Radiation, 20(2), p.219 - 225, 2013/03

https://doi.org/10.1107/S0909049512049813

A Si(111) winged crystal has been designed to minimize anticlastic bending and improve sagittal focusing efficiency. The crystal was thin with wide stiffening wings. The length-to-width ratio of the crystal was optimized by finite element analysis, and the optimal value was larger than the "golden value". The analysis showed that the slope error owing to anticlastic bending is less than the Darwin width. The X-rays were focused two-dimensionally using the crystal and a tangentially bent mirror. The observed profiles of the focal spot agreed well with the results of a ray-tracing calculation in the energy range from 8 to 17.5 keV. X-ray diffraction measurements with a high signal-to-noise ratio using this focusing system were demonstrated for a small protein crystal.

Azimuthal correlations of electrons from heavy-flavor decay with hadrons in and Au+Au collisions at = 200 GeV

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

Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04

https://doi.org/10.1103/PhysRevC.83.044912

Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to collisions.

Deuterium depth profiling in JT-60U W-shaped divertor tiles by nuclear reaction analysis

Hayashi, Takao; Ochiai, Kentaro; Masaki, Kei; Goto, Yoshitaka*; Kutsukake, Chuzo; Arai, Takashi; Nishitani, Takeo; Miya, Naoyuki

Journal of Nuclear Materials, 349(1-2), p.6 - 16, 2006/02

https://doi.org/10.1016/j.jnucmat.2005.06.019

Deuterium concentrations and depth profiles in plasma-facing graphite tiles used in the divertor of JT-60U were investigated by NRA. The highest deuterium concentration of D/C of 0.053 was found in the outer dome wing tile, where the deuterium accumulated probably through the deuterium-carbon co-deposition. In the outer and inner divertor target tiles, the D/C data were lower than 0.006. Additionally, the maximum (H+D)/C in the dome top tile was estimated to be 0.023 from the results of NRA and SIMS. OFMC simulation showed energetic deuterons caused by NBI were implanted into the dome region with high heat flux. Furthermore, the surface temperature and conditions such as deposition and erosion significantly influenced the accumulation process of deuterium. The deuterium depth profile, SEM observation and OFMC simulation indicated the deuterium was considered to accumulate through three processes: the deuterium-carbon co-deposition, the implantation of energetic deuterons and the deuterium diffusion into the bulk.

Measurement of deuterium and tritium retentions on the surface of JT-60 divertor tiles by means of nuclear reaction analysis

Ochiai, Kentaro; Hayashi, Takao; Kutsukake, Chuzo; Goto, Yoshitaka*; Masaki, Kei; Arai, Takashi; Miya, Naoyuki; Nishitani, Takeo

Journal of Nuclear Materials, 329-333(Part1), p.836 - 839, 2004/08

https://doi.org/10.1016/j.jnucmat.2004.04.292

no abstracts in English

Mass asymmetric fission of a nucleus produced in the Li + W reaction

Tamura, Nobuyuki; Hirose, Kentaro; Nishio, Katsuhisa; Nishinaka, Ichiro; Makii, Hiroyuki; Orlandi, R.; Lguillon, R.; Smallcombe, J.; Andreyev, A. N.; Otsuki, Tsutomu*; et al.

no journal, , 

no abstracts in English

Induced fission studies of Z 82 nuclei at the JAEA Tandem Facility

Smallcombe, J.; Nishio, Katsuhisa; Hirose, Kentaro; Nishinaka, Ichiro; Makii, Hiroyuki; Orlandi, R.; Tamura, Nobuyuki*; Goto, Shinichi*; Otsuki, Tsutomu*; Andreyev, A.*; et al.

no journal, , 

Measurement of nucleon-transfer fission in O + Cm reaction

Hirose, Kentaro; Nishio, Katsuhisa; Lguillon, R.; Smallcombe, J.; Nishinaka, Ichiro; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Chiba, Satoshi*; Otsuki, Tsutomu*; et al.

no journal, , 

no abstracts in English

Adsorption behavior of lawrencium (Lr) on a tantalum surface

Sato, Tetsuya; Kaneya, Yusuke*; Asai, Masato; Tsukada, Kazuaki; Toyoshima, Atsushi; Mitsukai, Akina*; Osa, Akihiko; Makii, Hiroyuki; Nishio, Katsuhisa; Hirose, Kentaro; et al.

no journal, , 

The ground state electronic configuration of lawrencium (Lr, Z =103) is predicted to be [Rn], which is different from that of the lanthanide homolog Lu [Xe] due to strong relativistic effects. According to semi-empirical considerations, volatility of Lr is expected to be higher than that of Lu. We have investigated adsorption behavior of Lr, which was produced in the reaction of Cf(B, 4n), on a tantalum (Ta) metal surface using a surface ion-source installed into the isotope separator on-line (ISOL) at the JAEA tandem accelerator facility. The observed adsorption behavior of Lr was similar to those of Tb and Lu which have relatively higher adsorption enthalpy on Ta surface. It implies that Lr would have low volatility like such as Lu and Tb.