Establishment of characterization method for small fuel debris using the world's first isotope micro imaging apparatus (Contract Research); FY2021 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Kogakuin University*

JAEA-Review 2024-005, 79 Pages, 2024/06

JAEA-Review-2024-005.pdf:5.72MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2021, this report summarizes the research results of the "Establishment of characterization method for small fuel debris using the world's first isotope micro imaging apparatus" conducted in FY2021. The present study aims to obtain, for the first time in the world, the important data necessary for clarifying the retrieval of small amounts of fuel debris, and to evaluate and examine them. SEM-EDS and TEM-EDS cannot be used for isotopic identification and analysis of Pu and B. On the other hand, bulk analysis such as ICP-MS lacks the information in a micro region.

Annual report of Department of Research Reactor and Tandem Accelerator, JFY2017 (Operation, utilization and technical development of JRR-3, JRR-4, NSRR, Tandem Accelerator, RI Production Facility and Tritium Process Laboratory)

Department of Research Reactor and Tandem Accelerator

JAEA-Review 2020-073, 113 Pages, 2021/03

JAEA-Review-2020-073.pdf:3.87MB

The Department of Research Reactor and Tandem Accelerator is in charge of the operation, utilization and technical development of JRR-3 (Japan Research Reactor No.3), JRR-4 (Japan Research Reactor No.4), NSRR (Nuclear Safety Research Reactor), Tandem Accelerator, RI Production Facility and Tritium Process Laboratory. This annual report describes the activities of our department in fiscal year of 2017. We carried out the operation and maintenance, utilization, upgrading of utilization techniques, safety administration and international cooperation. Also contained are lists of publications, meetings, granted permissions on laws and regulations concerning atomic energy, outcomes in service and technical developments and so on.

Application of automated particle screening for effective analysis of individual uranium particles by thermal ionization mass spectrometry

Esaka, Fumitaka; Suzuki, Daisuke; Yomogida, Takumi; Magara, Masaaki

Analytical Methods, 8(7), p.1543 - 1548, 2016/02

AA2015-0572.pdf:0.66MB

https://doi.org/10.1039/C5AY02841H

The isotope ratio analysis of individual uranium particles in environmental samples taken at nuclear facilities is important to clarify their origins for nuclear safeguards. In the present study, automated particle screening was used to select uranium particles prior to precise isotope ratio analysis by thermal ionization mass spectrometry (TIMS). As a result, molecular ion interferences on the uranium mass region were able to be almost completely avoided in the analysis of real inspection samples using APM-TIMS. Therefore, the performance of APM-TIMS was sufficient for obtaining isotope ratio data of individual particles without molecular ion interferences.

Optical frequency comb opens up highly efficient isotope separation of long-lived fission products; The Quantum walk to reduce radioactive waste

Yokoyama, Keiichi; Matsuoka, Leo*

Nihon Genshiryoku Gakkai-Shi ATOMO, 56(8), p.525 - 528, 2014/08

https://doi.org/10.3327/jaesjb.56.8_525

With respect to the isotope separation of cesium, one of the long-lived fission products, the background, principle, feasibility, and research activity in Kansai Photon Science Institute are described.

Study on the etching conditions of polycarbonate detectors for particle analysis of safeguards environmental samples

Iguchi, Kazunari; Esaka, Konomi; Lee, C. G.; Inagawa, Jun; Esaka, Fumitaka; Onodera, Takashi; Fukuyama, Hiroyasu; Suzuki, Daisuke; Sakurai, Satoshi; Watanabe, Kazuo; et al.

Radiation Measurements, 40(2-6), p.363 - 366, 2005/11

https://doi.org/10.1016/j.radmeas.2004.12.018

In particle analysis for safeguards environmental samples, the fission track technique is very important to detect sub-micrometer particles containing uranium. In the technique the authors developed, the particles were recovered onto the polycarbonate membrane filter. The filter was dissolved in solvent and dried to form a thin film of detector, in which the particles were confined. After thermal neutron irradiation and etching, the particles of interest in the detector were easily identified with fission tracks, and were picked up for isotope ratio analysis. It was found, however, that the particles in the vicinity of the detector surface may fall off during the etching process. Therefore, optimization of the etching condition is required. In this work, the effects of etching time and enrichment of uranium in particles were investigated. Preliminary results suggest that etching time should be shorter with the increase in the enrichment.

Numerical analysis of fractional distillation characteristics for radioactive metallic waste vaporized in the shape of atomic beam

Akaoka, Katsuaki; Maruyama, Yoichiro

Nihon Genshiryoku Gakkai Wabun Rombunshi, 4(2), p.127 - 134, 2005/06

https://doi.org/10.3327/taesj2002.4.127

The fractional distillation characteristics of the materials used for the reactor pressure vessel made of ASTM A302B and the structures in reactor made of SUS304 which are the radioactive metallic waste of Japan Power Demonstration Reactor (JPDR) were analyzed numerically. In the simulation, the vaporization rates of the components of the waste were calculated by using the Langmuir's equation and Henry's law. As the result of simulation, it was calculated that Eu, Eu, C and Nb can be reduced to less than clearance level by the fractional distillation. On the ASTM A302B case, it was pointed out that the other radioactive nuclei which are Mn, Fe, Co, Ni and Ni satisfy clearance level after 77 years cooling down. On the SUS304 case, it was pointed out that Ni and Ni must be separated to satisfy clearance level using isotope separation.

Numerical analysis of fractional distillation characteristics for radioactive metallic waste

Akaoka, Katsuaki; Maruyama, Yoichiro

JAERI-Research 2004-012, 12 Pages, 2004/08

JAERI-Research-2004-012.pdf:3.52MB

The fractional distillation characteristics at between 0 C and 2500 C(the rate is 200 C/h) of radioactive metallic waste for JPDR which mainly consists of stainless steel were analyzed numerically. In the simulation, the vaporization rates of the components of JPDR waste were calculated by using the Langmuir's equation and Henry's law. As the results, it was calculated that Eu, C and Nb can be removed by the fractional distillation. On the other hand, Mn and Fe can be reduced by cooling them for about 30 years. Therefore, by removing Ni and Co using laser separation method, it will be possible to reduce the radioactive metallic waste by less than one one-hundredth.

-ray spectroscopy for neutron-rich A160-170 nuclei; The decay of Pm, Sm, Eu, Gd, and Tb

Asai, Masato; Ichikawa, Shinichi; Tsukada, Kazuaki; Osa, Akihiko; Nishinaka, Ichiro; Nagame, Yuichiro; Kojima, Yasuaki*; Shibata, Michihiro*

Fission and Properties of Neutron-Rich Nuclei; Proceedings of 3rd International Conference, p.227 - 232, 2003/10

Structure of neutron-rich A160-170 nuclei produced in the proton-induced fission has been studied through -ray spectroscopy using an on-line isotope separator. decays of Pm, Sm, and Gd have been observed for the first time, and their half-lives were determined. Excited states of their daughter nuclei were revealed. rays following the decay of Eu and Gd have been also observed. The results suggest that the ground state of Eu would have a spin 5 or 6.

NuTEC annual report; April l, 2001 - March 31, 2002

Nuclear Technology and Education Center

JAERI-Review 2003-003, 81 Pages, 2003/05

JAERI-Review-2003-003.pdf:3.48MB

This report summarizes the educational activities and related management of the Nuclear Technology andEducation Center (NuTEC) during the 2001 fiscal year. Both Tokyo and Tokai Education Centers have successfully conducted almost all the planned domestic and international training courses. In addition Tokai Education Center has performed the 3nd nuclear supervisor training course and introduced a new course for special nuclear emergency preparedness in response to the legal amendment after the criticality accident. The sum total number of participants was 1,310. The International Technology Transfer Division has not only planned and organized the international training courses, but also taken charge of the 3nd workshop on Human Resource Development in Nuclear Field in Asian and Pasific Region. Various researches have been made to improve the educational program.

Proceedings of the Workshop on Applications of IRFEL and Nuclear Isomers; Septemper 28, 2001, JAERI, Tokai, Japan

Yamauchi, Toshihiko; Hayakawa, Takehito; Shizuma, Toshiyuki

JAERI-Conf 2002-007, 54 Pages, 2002/08

JAERI-Conf-2002-007.pdf:5.32MB

The workshop on application of free-electron laser (FEL) and nuclear isomer study was held at Tokai Research Establishment of JAERI on September 28. The workshop was devoted to the discussions and the presentations of two thema as follows: Six papers associated with the laser compton gamma-ray, the photonuclear physics and the nuclear astrophysics using the gannma-ray produced by the T3 laser were presented in the morning session. Seven papers including an invited talk on the behavior of molecules in intense laser light fields and associated with the chemical decomposition of dioxin, the silicon isotope separetion, the infrared photoexcitation spectroscopy, the laser-tissue interaction and the single-wall carbon nanotube and nanohorn by FEL etc. were also presented in the afternoon session. The intensive discussion was exchanged among approximately 50 participants. Each performance during the first workshop was fully telecomunicated by a video conference system between Tokai and Kizu (Kansai Research Establishment) sites.