Annual report on the effluent control of low level liquid waste in Nuclear Fuel Cycle Engineering Laboratories FY2021

Nakada, Akira; Kanai, Katsuta; Kokubun, Yuji; Nagaoka, Mika; Koike, Yuko; Yamada, Ryohei*; Kubota, Tomohiro; Hirao, Moe; Yoshii, Hideki*; Otani, Kazunori*; et al.

JAEA-Review 2022-079, 116 Pages, 2023/03

JAEA-Review-2022-079.pdf:2.77MB

Based on the regulations (the safety regulation of Tokai Reprocessing Plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and by law of Ibaraki Prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2021. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.

Annual report on the effluent control of low level liquid waste in Nuclear Fuel Cycle Engineering Laboratories FY2019

Nakano, Masanao; Fujii, Tomoko; Nagaoka, Mika; Koike, Yuko; Yamada, Ryohei; Kubota, Tomohiro; Yoshii, Hideki*; Otani, Kazunori*; Hiyama, Yoshinori*; Kikuchi, Masaaki*; et al.

JAEA-Review 2020-070, 120 Pages, 2021/02

JAEA-Review-2020-070.pdf:2.47MB

Based on the regulations (the safety regulation of Tokai Reprocessing Plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and by law of Ibaraki Prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2019. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.

Annual report on the effluent control of low level liquid waste in Nuclear Fuel Cycle Engineering Laboratories FY2017

Nakano, Masanao; Fujita, Hiroki; Mizutani, Tomoko; Nagaoka, Mika; Inoue, Kazumi; Koike, Yuko; Yamada, Ryohei; Yoshii, Hideki*; Hiyama, Yoshinori*; Otani, Kazunori*; et al.

JAEA-Review 2018-028, 120 Pages, 2019/02

JAEA-Review-2018-028.pdf:2.69MB

Based on the regulations (the safety regulation of Tokai Reprocessing Plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and by law of Ibaraki Prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2017. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.

A Simulation study for closed cycle and continuous hydrogen production by a thermo-chemical water-splitting IS process

Kubo, Shinji; Kasahara, Seiji; Sato, Hiroyuki; Imai, Yoshiyuki; Iwatsuki, Jin; Tanaka, Nobuyuki; Miyashita, Reiko*; Tago, Yasuhiro*; Onuki, Kaoru

Proceedings of 16th Pacific Basin Nuclear Conference (PBNC-16) (CD-ROM), 6 Pages, 2008/12

A stable hydrogen production via the IS process is relatively difficult because of the unique characteristics of the closed-cycle condition involved. This issue is therefore a high targeted priority when industrializing the process as feasible in a chemical plant. In system of IS process coupled with helium gas heat source, a process control method to maintain mass balance of the process was devised. The method is equipped with measurements of Bunsen reaction composition and allocation of heat for the O and H production sections in strict proportion. Via computer simulation for closed-cycle and fully multi-section driven by high-temperature helium gas, the system worked automatically to maintain stoichiometric production ratio in response to shifts of helium gas conditions.

Effects of microstructural evolution on charpy impact properties of modified ferritic/martensitic steel after neutron irradiation

Yano, Yasuhide; Oka, Keiichiro*; Akasaka, Naoaki; Yoshitake, Tsunemitsu; Abe, Yasuhiro; Onuki, Somei

Journal of Nuclear Science and Technology, 43(6), p.648 - 654, 2006/06

https://doi.org/10.3327/jnst.43.648

The embrittlement behavior of the modified ferritic/martensitic 11Cr-0.5Mo-2W, V, Nb steel (PNC-FMS) after neutron irradiation in JOYO was investigated by Charpy impact tests and TEM and SEM observations. The impact properties of the specimens after irradiation to 4.4 dpa at 773 K were similar to the as-received PNC-FMS. The ductile-brittle transition temperature (DBTT) remarkably decreased due to irradiation to 2.8 dpa at 923 K. The precipitates formed in the martensitic lath were still stable under neutron irradiation at 773 K, however they were unstable under irradiation at 923 K. The martensitic lath structure was also stable at the former irradiation temperature, but it was significantly changed at the latter. The decrease in the upper shelf energy after irradiation was related to the precipitate distribution. The changes of DBTT due to irradiation were attributed to decreased the dislocation recovery and to increased broadening of the martensitic lath.

Fe Mssbauer spectroscopic study of UFe

Tsutsui, Satoshi; Kobayashi, Yasuhiro*; Nakada, Masami; Nasu, Saburo*; Yamamoto, Etsuji; Haga, Yoshinori; Onuki, Yoshichika

Journal of the Physical Society of Japan, 69(6), p.1764 - 1768, 2000/06

https://doi.org/10.1143/JPSJ.69.1764

no abstracts in English

Closed cycle and continuous operation by a thermo-chemical water-splitting IS process

Kubo, Shinji; Ohashi, Hirofumi; Kanagawa, Akihiro; Kasahara, Seiji; Imai, Yoshiyuki; Fukui, Hiroshi*; Nishibayashi, Toshiki*; Shimazaki, Masanori*; Miyashita, Reiko*; Tago, Yasuhiro*; et al.

no journal, , 

For a stable hydrogen production, essential problems with the closed-cycle operation are declared, and the cycle can ensure these are retained in a steady state in case the H production rate, O production rate and HO supply rate have equivalent values. Process control methods used to maintain the mass balance of the process were devised, involving the installation of accumulators for the total system, techniques to maintain the Bunsen reaction composition and so on. For the plant operation, both controlled and manipulated variables were determined, while computer simulation and the bench scale H production test were used to confirm control methods. For closed cycle operation for water splitting driven by helium gas heat, the method is discussed to allocate heat for the O and H production sections in strict proportion. Finally, the use of computer simulation for the O production system allowed the key to maintaining heat balance within a cascade heat absorption system to be confirmed.