Current status of decommissioning and waste management at the Ningyo-Toge Environmental Engineering Center

Ohashi, Yusuke; Shimaike, Masamitsu; Matsumoto, Takashi; Takahashi, Nobuo; Yokoyama, Kaoru; Morimoto, Yasuyuki

Nuclear Technology, 209(5), p.777 - 786, 2023/05

https://doi.org/10.1080/00295450.2022.2145136

At the Ningyo-Toge Center, technical development related to uranium refining conversion and enrichment has been completed, and decommissioning of these facilities has begun. The error between the quantity of dismantled materials estimated from the facility design drawings and the actual quantity of dismantled materials was minimal when averaging over the entire Uranium Refining and Conversion Plant and Uranium Enrichment Engineering Facility, which results indicated that the preliminary estimate of the quantity of dismantled materials for decommissioning was reasonable. Most of the dismantled materials, which have no contamination history and are properly managed were able to be carried out to recyclers as non-radioactive waste (NR). In addition, the possibility of evaluating the uranium concentration of clearance level in dismantled objects was confirmed through gamma-ray measurement tests using mock-up waste.

Age and speciation of iodine in groundwater and mudstones of the Horonobe area, Hokkaido, Japan; Implications for the origin and migration of iodine during basin evolution

Togo, Yoko*; Takahashi, Yoshio*; Amano, Yuki; Matsuzaki, Hiroyuki*; Suzuki, Yohei*; Terada, Yasuko*; Muramatsu, Yasuyuki*; Ito, Kazumasa*; Iwatsuki, Teruki

Geochimica et Cosmochimica Acta, 191, p.165 - 186, 2016/10

https://doi.org/10.1016/j.gca.2016.07.012

Iodine distribution, speciation, and isotope ratio (I/I) in both rock and groundwater phases were determined to investigate long-term migration of iodine in diatomaceous and siliceous shale. It was suggested that I is released to the ground water during the progress of the maturation of organic matter. Dissociated I could move toward the surface because of the upward water flow driven by the compaction during burial diagenetic process. Thus, iodine rich brine is created by integration of iodine released from underlying formations. Because of low affinity of I to solid phase, released I remains in solution phase, and the concentration of the iodine in the solution has been possibly increasing during sedimentation history.

Current status of a decommissioning project in the Enrichment Engineering Facilities; Results in the first-half of the fiscal year of 2014

Matsumoto, Takashi; Morimoto, Yasuyuki; Takahashi, Nobuo; Takata, Masaharu; Yoshida, Hideaki; Nakashima, Shinichi; Ishimori, Yuu

JAEA-Technology 2015-036, 60 Pages, 2016/01

JAEA-Technology-2015-036.pdf:9.15MB

The Enrichment Engineering Facilities of the Ningyo-toge Environmental Engineering Center was constructed in order to establish the technical basis of the uranium enrichment plant in Japan. Uranium enrichment tests, using natural and reprocessed uranium, were carried out from 1979 to 1990 at two types of plants in the facilities. UF handling equipment and Supplemental equipment in these plants are intended to be dismantled by 2019 in order to make places for future projects, for example, inventory investigation, precipitation treatment, etc. This report shows the basic plan of this decommissioning project and presents the current state of dismantling in the first-half of the fiscal year of 2014, with indicating its schedule, procedure, situation, results, and so on. The dismantled materials generated amounted to 37 mesh containers and 199 drums, and the secondary waste generated amounted to 271.4 kg.

Development of in-reactor observation system using Cherenkov light(VI)

Takeuchi, Tomoaki; Yamamoto, Keiichi; Otsuka, Noriaki; Shibata, Hiroshi; Shibata, Akira; Takemoto, Noriyuki; Tsuchiya, Kunihiko; Sano, Tadafumi*; Unesaki, Hironobu*; Fujihara, Yasuyuki*; et al.

KURRI Progress Report 2014, P. 108, 2015/07

http://www.rri.kyoto-u.ac.jp/PUB/report/PR/ProgRep2014/CO3.pdf

Investigation of a relation between output power and brightness of Cherenkov light of a specific fuel element at KUR by a CCD camera was performed due to a development of a real-time in-core measurement technique using Cherenkov light. The results indicate that the inhomogeneous distribution of output power and the shadow of the control-rod guide tubes and the other irradiation equipment have significant effects on the brightness of the Cherenkov light. These effects could be suppressed by using a number of cameras located at various positions.

Status quo of the injector for the IFMIF/EVEDA prototype accelerator

Shinto, Katsuhiro; Ichikawa, Masahiro; Takahashi, Yasuyuki*; Kubo, Takashi*; Tsutsumi, Kazuyoshi; Kikuchi, Takayuki; Kasugai, Atsushi; Sugimoto, Masayoshi; Gobin, R.*; Girardot, P.*; et al.

Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1009 - 1012, 2014/10

http://www.pasj.jp/web_publish/pasj2014/proceedings/PDF/SUP0/SUP025.pdf

The prototype accelerator is being developed as an engineering validation for the International Fusion Materials Irradiation Facility (IFMIF) equipped with an accelerator-driven-type neutron source for developing fusion reactor materials. This prototype accelerator is a deuteron linear accelerator consisting of an injector, an RFQ, a superconducting linac and their auxiliaries. It aims to produce a CW D beam with the energy and current of 9 MeV/125 mA. The injector test was completed at CEA/Saclay in 2012 for producing a CW H beam and a CW D beam with the energy and current of 100 keV/140 mA. After the beam test at CEA/Saclay, the injector was transported to the International Fusion Energy Research Centre (IFERC) located in Rokkasho, Aomori, Japan. In the end of 2013, installation of the injector was started at IFERC for the injector beam test beginning from summer 2014 in order to obtain better beam qualities to be satisfied with the injection and acceleration of the following accelerators. In this paper, some results of the injector beam test performed at CEA/Saclay and the status quo of the installation of the injector at IFERC are presented.

The Possible interplanetary transfer of microbes; Assessing the viability of spp. under the ISS environmental conditions for performing exposure experiments of microbes in the Tanpopo mission

Kawaguchi, Yuko*; Yang, Y.*; Kawashiri, Narutoshi*; Shiraishi, Keisuke*; Takasu, Masako*; Narumi, Issey*; Sato, Katsuya; Hashimoto, Hirofumi*; Nakagawa, Kazumichi*; Tanigawa, Yoshiaki*; et al.

Origins of Life and Evolution of Biospheres, 43(4-5), p.411 - 428, 2013/10

https://doi.org/10.1007/s11084-013-9346-1

Electroplating of Ni microstructures on the cross section of Cu wire using PMMA mother fabricated by proton beam writing

Tanabe, Yusuke*; Iwamoto, Takashi*; Takahashi, Junichi*; Nishikawa, Hiroyuki*; Sato, Takahiro; Ishii, Yasuyuki; Kamiya, Tomihiro

JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 129, 2013/01

https://doi.org/10.11484/jaea-review-2012-046

Energy dependence of nonlinear effects of sputtering yields of Si bombarded with 10-540-keV C ions

Narumi, Kazumasa; Naramoto, Hiroshi*; Yamada, Keisuke; Saito, Yuichi; Chiba, Atsuya; Takahashi, Yasuyuki*; Maeda, Yoshihito

JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 155, 2012/01

https://doi.org/10.11484/jaea-review-2011-043

no abstracts in English

Measurement of divergence angles classified by charge-state combination of C constituents passing through a thin carbon foil

Chiba, Atsuya; Saito, Yuichi; Narumi, Kazumasa; Takahashi, Yasuyuki; Yamada, Keisuke; Kaneko, Toshiaki*

Nuclear Instruments and Methods in Physics Research B, 269(9), p.824 - 828, 2011/05

https://doi.org/10.1016/j.nimb.2010.12.002

It is necessary to clarify the relationship between the internuclear distance of the cluster constituent ions and these charge states for the elucidation of mechanism of the vicinage effects which are expressed due to the interaction with matter. Therefore the coincidence measurement between divergence angles and final charge states of the constituent ions resulting from dissociation of 6-MeV C ions in a thin carbon foil were performed. The strong dependence of the final charge state of constituent ions on the initial internuclear distance of projectile ion was quantitatively indicated by the fitting analysis of the angular distributions for various final charge-state combinations using the Monte Carlo particle trajectory simulation.

Relationship between internuclear distance and charge state of constituent ions resulting from foil-induced dissociation of C ions

Chiba, Atsuya; Saito, Yuichi; Narumi, Kazumasa; Takahashi, Yasuyuki; Yamada, Keisuke; Kaneko, Toshiaki*

JAEA-Review 2010-065, JAEA Takasaki Annual Report 2009, P. 163, 2011/01

https://jopss.jaea.go.jp/pdfdata/JAEA-Review-2010-065.pdf

The evaluation of the charge state and charge exchange process of the cluster constituent ions inside solid is extremely important for the clarification of the vicinage effect, because the essential interaction forces such as stopping power, wake force and Coulomb repulsion is strongly correlated to the charge state of individual constituent ions. Therefore, the measurement of the divergence angular distributions classified into the charge-state combination of constituent ions resulting from foil-induced dissociation of 6-MeV C ions was carried out in order to investigate the relationship between the internuclear distance and the charge state of individual constituent ions. We suggests that the final charge-state combination of constituents emerging from the foil depends on the initial internuclear-distance which is fluctuated due to a vibration excitation of C ion.