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Emori, Tatsuya; Kitatsuji, Yoshihiro; Ban, Yasutoshi
JAEA-Technology 2024-025, 20 Pages, 2025/03
JAEA-Technology-2024-025.pdf:1.65MB
Radioisotope Thermoelectric Generators (RTGs) using the decay heat of Pu-238 has been applied for outer planet missions far from Jupiter, where solar power is limited. However, no facilities are available to produce Pu-238 for space probes in Japan. Moreover, the use of nuclear materials for the space exploration is difficult in term of the regulation. Thus, we focused on Am-241 whose half-life is around 432 years as an alternative heat source for RTGs. This report describes the procedure of separating Am-241 decayed from Pu-241 in aged plutonium oxide. Two experiments were performed: one using solid-liquid extraction and the other combining liquid-liquid extraction and solid-liquid extraction. Packed columns were used in the experiments, with their number reduced by less than one-fifth in the latter experiment compared to the former. Furthermore, the time required for separation in the latter experiment was less than half that of the former. We performed the separation experiments six times, collecting a total of approximately 0.43 g of Am-241 as an oxalate salt.
Ieda, Junichi; Fukada, Yukimasa; Fukuda, Tatsuo
Nihon Genshiryoku Gakkai-Shi ATOMO
, 66(10), p.521 - 524, 2024/10
no abstracts in English
Matsueda, Makoto
Hosha Kagaku, (50), p.55 - 57, 2024/09
Concentrations and isotope ratios of 
Tc, 
I, and Pu isotopes, which are long-lived nuclides, provide us the important information in many fields such as the decommissioning of nuclear facilities and investigation of environmental dynamics. It will increase the effort for their analysis in the future. Therefore, their analytical methods should be developed for corresponding many samples, and inductively coupled plasma mass spectrometry (ICP-MS) is expected to be a technique to help resolve them. However, there are some problems in the analysis of these nuclides, and technological innovations have not progressed yet. In this paper, we attempted to solve these problems by combining multiple separation systems with ICP-MS.
Matsueda, Makoto; Takagai, Yoshitaka*
Bunseki (Internet), 2024(6), p.195 - 200, 2024/06
The analytical demand for radioisotopes (RI) contained in radioactive waste from the decommissioning of nuclear power plants, research activities and nuclear accidents is increasing. However, traditional analytical methods of RI are mostly complicated and time-consuming, it is necessary to be rapid, simple and automatic methods. This paper describes the rapid analytical techniques of inductively coupled plasma-mass spectrometry in recent years, which current technology, challenges and perspective for the future.
Kusaka, Ryoji
Bunko Kenkyu, 67(6), p.239 - 240, 2018/12
A spectroscopic technique for analysis developed by collaboration between Japan Atomic Energy Agency (JAEA) and Quantum and Radiological Science and Technology (QST) is discussed for readers outside the field of nuclear energy. This paper introduces a quantitative analysis for 
Pd radioisotope contained in a spent nuclear fuel by using laser-induced photoreduction and inductively coupled plasma mass spectrometry (ICP-MS). The importance and problems of quantitative analysis for radioisotopes in spent nuclear fuels are described, and the principle, advantages, and future applications of the spectroscopic technique are discussed.
Tanaka, Tadao; Mukai, Masayuki; Maeda, Toshikatsu; Munakata, Masahiro; Matsumoto, Junko; Ogawa, Hiromichi; Bamba, Tsunetaka*; Wang, Z.*; Yang, Y.*; Zhao, Y.*
Proceedings of International Symposium on Radioecology and Environmental Dosimetry, p.179 - 184, 2003/00
Migration behaviors of stable strontium element and radioactive nuclide strontium 90 in natural aquifer were studied by a field test, which was performed in the aquifer loess zone at 30 m under the ground surface of the field test site of China Institute for Radiation Protection. The migration behavior of stable strontium was a little different from that of 
Sr. The difference was evaluated by applying the distribution coefficient considering Sr and coexistent ion concentrations. Migration behavior of radionuclide in natural environment has been generally demonstrated on field tests without radioactive tracers and/or large-scale column tests with radioactive tracers. Such tests seem to be valuable to improve reliability of the migratory evaluation.
Kushita, Kohei
JAERI-Review 2001-043, 95 Pages, 2001/12
JAERI-Review-2001-043.pdf:4.04MB
no abstracts in English
; ; ; Omori, Eiichi
JNC TN8410 2001-021, 33 Pages, 2001/09
JNC-TN8410-2001-021.pdf:4.37MB
Carbon-14 released from the nuclear facilities is an important radionuclide for the safety assessment, because it tends to accumulate in environment through food chain and has as a significant impact to personal dose. Carbon-14 has been monitored routinely as one of the main gaseous radionuclides exhausted from the Tokai Reprocessing Plant (TRP) since OCtober of 1991. Furthermore, behavior of carbon-14 in TRP has been investigated through the reprocessing operation and the literature survey. This report describes the result of investigation about the behavior of carbon-14 in TRP as followings. (1)Only a very small amount of carbon-14 in the fuel was liberated into the shear off-gas and most of it was liberated into the dissolver of-gass. Part of the carbon-14 was trapped at the caustic scrubber installed in the of-gas treatment process, and untrapped carbon-14 was released into the environment from the main stack. Amount of carbon-14 released from the main stack was about 4.1
6.5GBq every ton of uranium reprocessed. (2)Carbon-14 trapped at the caustic scrubbers installed in the dissolver off-gas and in the vessel off-gas treatment process is transferred to the low active waste vessel. Amount of carbon-14 transferred to the low active waste vessel was about 5.4 9.6GBq every ton of uranium reprocessed. (3)The total amount of carbon-14 input to TRP was summed up to about 11.915.5 GBq every ton of uranium reprocessed considering the released amount from the main stack and the trapped amount in the off-gas treatment devices. The amount of nitrogen impurity in the initial fuel was calculated about 1522ppm of uranium metal based on the measured carbon-14. (4)The solution in the low active waste vesselis concentrated at the evaporator.Most of the carbon-14 in the solution was transferred into concentrated solution. (5)Tokai vitrification Demonstration Facility (TVF) started to operate in 1994. Since then, carbon-14 has been measured in the ...
; Kondo, Toshiyuki;
JNC TN8440 2001-024, 210 Pages, 2001/08
JNC-TN8440-2001-024.pdf:24.99MB
In order to make this book reflect in the investigation which turned the bitumen solidification object to maintenance of the abandonment object technical standard on condition of carrying out subterranean disposal in the future - solidification - it created for the purpose of utilizing as precious sources of information, such as a nuclide inventory in the living body, group-izing of the past campaign required for typical solidification object selection, and information offer at the time of disposal examination. A development operation history collected so that histories including the shift action in an institution of the formation of discharge reduction of the characteristic of solidification object manufacture outlines, such as composition of the process of an institution and a solidification object and a storage actual result, the contents of an examination of the past campaign, and the solidification object manufactured based on topics or radioactive iodine and radioactive carbon etc., such as the past contents of an examination / operation, may grasp comprehensively in creation, and it carried out as the composition stared the trend of future disposal fixedly. It was a period (for 16 years) until an bituminization demonstration facility processing institution will start a cold examination from April (Showa 57), 1982, and it starts a hot examination from May 4, it starts solidification processing technical development operation from october 6 and it results in the fire explosion accident on March 11 (Heisei 9), 1997, and low level radioactivity concentration waste fluid was processed 7,438 m
, and 29,967 bitumen solidification objects were manufactured. According to the accident, it is necessary to hand it down to future generations with processing technology while the bitumen solidification object manufactured in 15 years although the bituminization demonstration facility processing institution came to close the mission holds information precious ...
Maruo, Yoshihiro; ; Takeishi, Minoru; ; ; Takeyasu, Masanori;
JNC TN8440 2001-011, 146 Pages, 2001/06
JNC-TN8440-2001-011.pdf:2.98MB
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed since 1975, based on "Safety Regulations for the Tokai Reprocessing Plant, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitants due to the radioactivity discharged from the plant during April 2000 to March 2001. Appendices present comprehensive information, such as monitoring program, monitoring results, meteorological data and annual discharges from the plant.
2000/12)Kobayashi, Hideo; ; ; ; ; ;
JNC TN8440 2001-005, 33 Pages, 2001/02
JNC-TN8440-2001-005.pdf:1.24MB
Four mass spectrometers are used for plutonium and uranium isotopic composition analysis in the Plutonium Fuel Center. Analytical errors of the analysis was evaluated based on routine control data obtained with measurement of reference materials. It was confirmed that the errors satisfied the International Target Values for safeguard analysis, and the random error of the analysis was improved by changing conventional method to total evaporation method.
Shinohara, Kunihiko; ; ; ; ; Kano, Yutaka;
JNC TN8440 2001-004, 62 Pages, 2001/02
JNC-TN8440-2001-004.pdf:4.17MB
Concerming about the action for the criticality accident in JCO Co., Ltd. (JCO) occurred at 10:35 on 30
Sept. 1999, Japan Nuclear Cycle Development Institute(JNC) established "JNC's task force" at 12:35 on the same date in conjuction with Head Office and Tokai Works. And JNC's task force had supported the government of Japan, the local governments and JCO humanly, physically and technically until the jobs of the task force was transferred to "Support Assembly for Countermeasure and Research of JCO Criticality Accident" and routine line on 12 Oct. 1999. This report compiled the results of the environmental monitoring performed by JNC based on the request from the government of Japan and the local governments.
; ; Morooka, Koichi*
JNC TJ8400 2000-043, 170 Pages, 2000/03
JNC-TJ8400-2000-043.pdf:7.63MB
This study is an object to collect and arrange data about the mass transfer path during a natural barrier system by grasping actual rock feature, in order to be useful for a performance assessment of a natural barrier system at geological disposal of HLW. An existence of permeability high large-scale faults extends a large influence over a performance assessment of geological disposal. With "The Second Progress Report on Research and Development for the Geological Disposal of HLW in Japan" which Nuclear Cycle Development Institute (JNC) issued, it is as" A repository would be located at least 100 meters away from major faults and major fracture zones which could adversely affect the stability and performance of the repository" as a Reference Case concept model of a natural barrier system, Then, they are as "in the Reference Case, the transport path consists of the host rock and the downstream fault". It will not be easy to know the distribution of faults in the subsurface deep division without data acquired from many boreholes and underground laboratory. With this study, specific data on the large-scale faults and fracture zones has been collected and arranged by investigating in underground galleries and on the literatures of a post-operated mine site. Based on this result, a consideration on the principal transfer pass at a natural barrier system has been conducted. The contents conducted in this report is the follows. (1)investigation of literature about data of fracture, shear zone, and geology, (2)field investigation of fracture and shear zone in the rock, (3)arrangement of these results, (4)modeling of the major water conductive feature, and (5)evaluation of an assumption which has been introduced in the Second Progress Report issued by JNC.
JNC TJ9400 2000-008, 61 Pages, 2000/02
For studies on nuclear transmutation of long-lived fission products (LLFPs) in a fast reactor, detailed characteristics of reactor core such as transmutation performance have to be investigated, so accurate neutron cross section data of LLFPs become necessary. Therefore, the keV-neutron capture cross sections of Tc-99, which is one of important LLFPs, were measured in the present study to obtain the accurate data. The measurement was relative to the standard capture cross sections of Au-197. A neutron time-of-flight method was adopted with a ns-pulsed neutron source by a Pelletron accelerator and a large anti-Compton NaI(TI) gamma-ray detector. As a result, the capture cross sections of Tc-99 were obtained with the error of about 5 % in the incident neutlon energy region of 10 to 600 keV. The present data were compared with other experimental data and the evaluated values of JENDL-3.2, and it was found that the evaluations of JENDL-3.2 were 15-20 % smaller than the present measurements.
Fujii, Toshiyuki*;
JNC TJ9400 2000-003, 36 Pages, 2000/02
JNC-TJ9400-2000-003.pdf:1.36MB
For establishing a recycling system based on low-decontamination, the distribution behaviors of radionuclides in the process are essential information for the design of the system. Molybdenum and palladium are less radioactive fission products, but attention should be paid to them because they are likely to extremely affect the performance of the recycled fuels. In this context, in this study, the extraction behaviors of molybdenum and palladium under conditions of PUREX and TRUEX extraction process were experimentally studied, and their chemical mechanisms were discussed. In cojunction with the extraction experiments, absorption spectrometry was applied to identify the related species and the extraction mechanism. As a result, knowledge for the distribution characteristics of molybdenum and palladium in PUREX and TRUEX process was reinforced.
Ikeda, Takao*; Yoshida, Hideji*; Miki, Takahito*
JNC TJ8400 2000-046, 264 Pages, 2000/02
JNC-TJ8400-2000-046.pdf:6.73MB
This report contains discussions about methodology for the selection of parameter values, stochastic approach for the biosphere assessment and biosphere modelling for marine discharge case are described. Regarding the methodology for the selection of parameter values, important aspects for the data selection were discussed, and data selection protocol was developed. Regarding the stochastic approach for the biosphere assessment, it is confirmed that Straightforward Monte Carlo Method and Latin Hypercube Sampling Method are the most adequate based on a literature survey. Then stochastic assessment by using biosphere model that was developed in the second progress report was carried out to check the sensitivity of parameter values. Finally, availability of several kind of assessment models for marine discharge case were discussed. It was confirmed that Multiple Compartment Model was the most applicable. Assessment using Multiple Compartment Model was carried out. The results were compared with those derived by numerical model. As a result, the difference between two models were small enough.
Ikeda, Takao*; Yoshida, Hideji*; Miki, Takahito*
JNC TJ8400 2000-045, 134 Pages, 2000/02
JNC-TJ8400-2000-045.pdf:4.12MB
None
Fukunaga, Sakae*; Yokoyama, Hidekazu*; Arai, Kazuhiro*; Asano, Hidekazu*; Senjyu, Takafumi*; Kudo, Akira*
JNC TJ8400 2000-030, 54 Pages, 2000/02
JNC-TJ8400-2000-030.pdf:1.69MB
It is easy to assume from the past data that microbial transport do not find at 100%-sodium bentonite. Microbial transport do not find at 100%-calcium bentonite too. There are no effects to distribution ration (Kd) of Neptunium (Np) and Plutonium (Pu) with bentonite by sterilizing on low Eh condition (Eh= -500mv). Kd values of Np and Pu show behavior, which are increasing on the hard acidic and alkali conditions. Especially, Kd values of Pu shows one of Kd value is about 100 ml/g on pH=36, but the other of Kd value is about 400,000 ml/g on pH=13. Precipitating plutonium hydrates occurred the large Kd value on alkali condition.
Fukunaga, Sakae*; Yokoyama, Hidekazu*; Arai, Kazuhiro*; Asano, Hidekazu*; Senjyu, Takafumi*; Kudo, Akira*
JNC TJ8400 2000-029, 36 Pages, 2000/02
JNC-TJ8400-2000-029.pdf:1.28MB
It is easy to assume from the past data that microbial transport do not find at 100%-sodium bentonite. Microbial transport do not find at 100%-calcium bentonite too. There are no effects to distribution ration (Kd) of Neptunium (Np) and Plutonium (Pu) with bentonite by sterilizing on low Eh condition (Eh = -500mv). Kd values of Np and Pu show behavior, which are increasing on the hard acidic and alkali conditions. Especially, Kd values of Pu shows one of Kd value is about 100 ml/g on pH = 36, but the other of Kd value is about 400,000 ml/g on pH = 13. Precipitating plutonium hydrates occurred the large Kd value on alkali condition.
