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Journal Articles

Two-step-pressurization method in pulsed electric current sintering of MoO$$_{3}$$ for production of $$^{99m}$$Tc radioactive isotope

Suematsu, Hisayuki*; Sato, Soma*; Nakayama, Tadachika*; Suzuki, Tatsuya*; Niihara, Koichi*; Nanko, Makoto*; Tsuchiya, Kunihiko

Journal of Asian Ceramic Societies (Internet), 8(4), p.1154 - 1161, 2020/12

 Times Cited Count:0 Percentile:100(Materials Science, Ceramics)

Pulsed electric current sintering of molybdenum trioxide (MoO$$_{3}$$) was carried out by one- and two-step pressuring methods for fabrication of irradiation target using production of $$^{99}$$Mo and $$^{rm 99m}$$Tc nuclear medicine. At 550$$^{circ}$$C by the two-step pressurizing method, a relative density of 93.1% was obtained while, by the one-step pressurization method, the relative density was 76.9%. Direct sample temperature measurements were conducted by inserting a thermocouple in a punch. By the two-step pressurizing method, the sample temperature was higher than that by the one-step pressurizing method even almost the same die temperature. From voltage and current waveforms, it was thought that the conductivity of the sample increased by the two-step pressurizing method to increase the sample temperature and the relative density. The two-step pressurization method enables us to prepare dense targets at a low temperature from recycled and coarse-grained $$^{98}$$Mo enriched MoO$$_{3}$$ powder.

Journal Articles

Adsorption mechanism of ReO$$_{4}$$$$^{-}$$ on Ni-Zn layered hydroxide salt and its application to removal of ReO$$_{4}$$$$^{-}$$ as a surrogate of TcO$$_{4}$$$$^{-}$$

Tanaka, Kazuya; Kozai, Naofumi; Yamasaki, Shinya*; Onuki, Toshihiko; Kaplan, D. I.*; Grambow, B.

Applied Clay Science, 182, p.105282_1 - 105282_8, 2019/12

 Times Cited Count:2 Percentile:63.86(Chemistry, Physical)

In this study, Ni-Zn layered hydroxide salt (LHS) was used for adsorption experiments of ReO$$_{4}$$$$^{-}$$, as a surrogate of TcO$$_{4}$$$$^{-}$$, in aqueous solutions with various initial Re and sodium salt concentrations. The maximum adsorption amount of Re was estimated at 127.7 mg/g (6.86 $$times$$ 10$$^{-4}$$ eq/g) by fitting adsorption isotherm of ReO$$_{4}$$$$^{-}$$ to Langmuir plot. The adsorption of ReO$$_{4}$$$$^{-}$$ at neutral pH was a reversible process by anion exchange, and decreased with increasing Cl$$^{-}$$, NO$$_{3}$$$$^{-}$$ and SO$$_{4}$$$$^{2-}$$ in solution. EXAFS analysis indicated that ReO$$_{4}$$$$^{-}$$ was adsorbed as an outer-sphere complex on Ni-Zn LHS. The Ni-Zn LHS is a more robust adsorbent for ReO$$_{4}$$$$^{-}$$ than the Mg-Al LDH in terms of solution pH and tolerance to competing anions, and may be an effective alternative to the traditional and more limited method of removing aqueous TcO$$_{4}$$$$^{-}$$ by reductive precipitation.

JAEA Reports

Performance tests of radiation detectors for inspection of $$^{99}$$Mo/$$^{99m}$$Tc solution, 1

Suzuki, Yumi*; Nakano, Hiroko; Suzuki, Yoshitaka; Ishida, Takuya; Shibata, Akira; Kato, Yoshiaki; Kawamata, Kazuo; Tsuchiya, Kunihiko

JAEA-Technology 2015-031, 58 Pages, 2015/11

JAEA-Technology-2015-031.pdf:14.57MB

Technetium-99m ($$^{99m}$$Tc) is one of the most commonly used radioisotopes in the field of nuclear medicine. In the Japan Atomic Energy Agency (JAEA), the research and development (R&D) have been carried out for production of molybdenum-99 ($$^{99}$$Mo) by (n, $$gamma$$) method, a parent nuclide of $$^{99m}$$Tc, with the Japan Material Testing Reactor (JMTR). On the other hand, the new project as "Domestic Production of Medical Radioisotope (Technetium preparation) in Japan" was adopted in the Tsukuba International Strategic Zone on October, 2013 and the demonstration tests will be planned for the domestic production of $$^{99}$$Mo/$$^{99m}$$Tc with the JMTR. Thus, new facilities and analysis devices were equipped in the JMTR hot laboratory in 2014 as the part of this project. As the part of the analytical device equipment, the $$gamma$$-TLC analyzer and the radiation detector connected with the High Performance Liquid Chromatography (HPLC) were installed for quality inspection of the $$^{99}$$Mo/$$^{99m}$$Tc solution and the extracted $$^{99m}$$Tc solution in the JMTR hot laboratory. The performance tests of these devices such as detection sensitivity, resolution, linearity and selectivity of energy range were carried out with $$^{137}$$Cs and $$^{152}$$Eu as alternative radionuclides of $$^{99}$$Mo and $$^{99m}$$Tc, respectively. In the results, bright prospects were obtained concerning the quality inspection of the $$^{99}$$Mo/$$^{99m}$$Tc and $$^{99m}$$Tc solutions using these devices. This report describes the results of those performance tests.

Journal Articles

Production and chemistry of transactinide elements

Nagame, Yuichiro

Journal of Nuclear and Radiochemical Sciences, 6(3), p.205 - 210, 2005/12

no abstracts in English

Journal Articles

An Advanced aqueous reprocessing process for the next generation's nuclear fuel cycle

Mineo, Hideaki; Asakura, Toshihide; Hotoku, Shinobu; Ban, Yasutoshi; Morita, Yasuji

Proceedings of GLOBAL2003 Atoms for Prosperity; Updating Eisenhower's Global Vision for Nuclear Energy (CD-ROM), p.1250 - 1255, 2003/11

An advanced aqueous reprocessing process has been proposed for the next generation fuel cycle. Key technologies applied to the process are: removal of I-129, separation of Np and FP(Tc) separation by selective reduction of Np(VI) and high acid scrubbing of Tc within a single cycle process, MA separation by extraction chromatography and Cs/Sr separation. U separation just after dissolution was supposed to be effective to reduce the required capacity of the following extraction step. Among them Np reduction rate in TBP solution was measured, which was found to be lower than that in aqueous solution. Using an improved flow sheet spent fuel test, based on the Np reduction test, was carried out and about 90% of Np was separated before U and Pu partitioning step.

JAEA Reports

Re-evaluation of neutron nuclear data for $$^{242m}$$Am, $$^{243}$$Am, $$^{99}$$Tc and $$^{140}$$Ce

Nakagawa, Tsuneo; Iwamoto, Osamu; Hasegawa, Akira

JAERI-Research 2002-035, 94 Pages, 2002/12

JAERI-Research-2002-035.pdf:2.73MB

no abstracts in English

Journal Articles

Study on reduction of neptunium and uranium in nitric acid solution using flow type electrolytic cell, as a basic technique for advanced reprocessing process

Asakura, Toshihide; Uchiyama, Gunzo; Hoshi, Harutaka*; Wei, Y.*; Kumagai, Mikio*

Journal of Nuclear Science and Technology, 39(Suppl.3), p.340 - 342, 2002/11

no abstracts in English

Journal Articles

Heat capacities of technetium metal and technetium-ruthenium alloy

Shirasu, Yoshiro; Minato, Kazuo

Journal of Alloys and Compounds, 337(1-2), p.243 - 247, 2002/05

 Times Cited Count:2 Percentile:75.46(Chemistry, Physical)

no abstracts in English

Journal Articles

Thermal expansions of technetium-ruthenium alloys

Shirasu, Yoshiro; Minato, Kazuo

Journal of Alloys and Compounds, 335(1-2), p.224 - 227, 2002/03

 Times Cited Count:6 Percentile:54.7(Chemistry, Physical)

no abstracts in English

JAEA Reports

The Sorption database of radionuclides for cementitious materials

Kato, Hiroshige*; Mine, Tatsuya*; Mihara, Morihiro; Oi, Takao; Honda, Akira

JNC-TN8400 2001-029, 63 Pages, 2002/01

JNC-TN8400-2001-029.pdf:1.81MB

Cementitious materials will be used for the TRU waste repository as a component of engineered barrier system. The distribution coefficients which represent the retardation of radionuclides migration for the cementitious materials would be one of the important parameter for the safety assessment. The much information of radionuclide sorption onto the cementitious materials has been accumulated through the study in the world. Therefore it is necessary to compile the information and Kd of the radionuclides reported in previous studies. In this report, the Kd of the important radionuclides, such as C, Ni, Se, Sr, Zr, Nb, Mo, Tc, Sn, I, Cs, Sm, Pb, Ra, Ac, Th, Pa, U, Np, Pu, Am, Cm, for the cementitious materials were compiled as the Sorption Database (SDB). For radionuclides to be sensitive to the redox potential, e.g. Se, Tc, Pa, U, Pu and Np, some Kds measured under the controlled atmosphere had been reported, and few Kds measured under the controlled redox potential had been reported. For Se, Mo, Sm, Cm and Ac, the distribution coefficients had not been reported, therefore distribution coefficients of Se and Mo for OPC (Ordinary Portland Cement) pastes were measured by batch sorption experiments and these data were added into the SDB.

Journal Articles

Solvent extraction behaviors of minor nuclides in nuclear fuel reprocessing process

Uchiyama, Gunzo; Asakura, Toshihide; Hotoku, Shinobu; Mineo, Hideaki; Kamei, Kazushige; Watanabe, Makio; Fujine, Sachio

Journal of Radioanalytical and Nuclear Chemistry, 246(3), p.683 - 688, 2000/12

 Times Cited Count:10 Percentile:40.67(Chemistry, Analytical)

no abstracts in English

JAEA Reports

A study on improvements in accuracy of nuclear data measurements using $$gamma$$-ray spectroscopic methods

Furutaka, Kazuyoshi

JNC-TN8400 2000-028, 70 Pages, 2000/10

JNC-TN8400-2000-028.pdf:1.71MB

This report describes the study done by the author as a postdoctoral research associate at Japan Nuclear Cycle Development Institute. This report is divided into two parts: improvements in accuracy in determination of thermal neutron capture cross sections, and improvements in accuracy of photo-nuclear absorption cross section measurements using the HHS. (1)In the measurements of thermal neutron capture cross sections using an activation method, accuracies of the final results attained are limited by (1) accuracy of $$gamma$$-ray peak detection efficiencies, and (2) accuracies of $$gamma$$-ray emission probabilities. In this study; to determine thermal neutron capture cross sections more accurately, the following researches have been done using a newly developed three-dimensional coincidence measurement system: (1)accurate determination of $$gamma$$-ray standard sources using a $$gamma$$-$$gamma$$ coincidence method, for precise calibration of $$gamma$$-ray peak detection efficiency, and (2) development of a $$beta$$-$$gamma$$ coincidence measurement system using a plastic scintillation detector as a $$beta$$-ray detector, for the determination of $$gamma$$-ray emission probabilities of short-lived nuclides, and measurement of $$gamma$$-ray emission probabilities of $$^{100}$$Tc nuclide using the coincidence system. (2)To transform radioactive nuclides with small thermal neutron capture cross sections, use of photonuclear absorption reaction has been suggested. In order to transform these nuclides efficiently using the reaction, one has to know detailed behavior of the photo-absorption cross sections. In this study, a Monte-Carlo simulation code has been used to create a standard set of $$gamma$$-ray response functions of the high-resolution high-energy spectrometer (HHS), to enable reliable analyses of the data obtained by the spectrometer.

JAEA Reports

Cold and semi-hot tests of 4-group partitioning process at NUCEF

Morita, Yasuji; Yamaguchi, Isoo; Fujiwara, Takeshi; Mizoguchi, Kenichi*; Kubota, Masumitsu*

JAERI-Research 2000-024, 55 Pages, 2000/06

JAERI-Research-2000-024.pdf:2.24MB

no abstracts in English

JAEA Reports

Investigation of equilibrium core by recycling MA and LLFP in fast reactor cycle (II) -lnvestigation of LLFP confined in eEquilibrium core with element separation-

Mizutani, Akihiko; ;

JNC-TN9400 2000-013, 66 Pages, 2000/02

JNC-TN9400-2000-013.pdf:1.97MB

Feasibility study on a self-consistent fuel cycle system has been performed in the nuclear fuel recycle system with fast reactors. ln this system, the self-generated MAs (Minor Actinides) and LLFPs (Long-Lived Fission Products) are confined and incinerated in the fast reactor, which is called the "Equilibrium Core" concept. However, as the isotope separations for selected LLFPs have been assumed in this cycle system, it seems that this assumption is far from realistic one from the viewpoint of economy with respect to the fuel cycle system. ln this study, the possibility for realization of the "Equilibrium Core" concept is evaluated for three fuel types such as oxide, nitride and metallic fuels, provided that the isotopic separation of LLFPs is changed to the element one. This study provides, that is to say, how many LLFP elements can be confined in the "Equilibrium Core" with element separation. This report examines the nuclear properties of the "Equilibrium Core" for various combinations of LLFP incineration schemes from the viewpoints of the risk of geological disposal and the limit in confinable quantity of LLFPs. From the viewpoint of the risk of geological disposal estimated by the retardation factor, it is possible to confine with element separation for T$$_{c}$$, I and Se even in the oxide fueled core. From the standpoint of the limit of confinable amounts of LLFPs, on the other hand, T$$_{c}$$, I, S$$_{e}$$, S$$_{n}$$ and Cs can be confined with element separation in case that the nitride fuel is chosen.

JAEA Reports

Preliminary experiment of neutron capture cross section of Tc-99 with lead slowing-down spectrometer

*

JNC-TJ9400 2000-009, 63 Pages, 2000/02

JNC-TJ9400-2000-009.pdf:2.48MB

The present status of nuclear data for technetium (Tc)-99, which is a well-known fission product (FP), has been reviewed and investigated. And making use of the Kyoto university Lead Slowing-down Spectrometer (KULS), the cross section of the $$^{99}$$Tc (n, $$gamma$$) $$^{100}$$Tc reaction has been measured in the energy range from thermal to keV neutron energy with an Ar-gas proportinal counter. The neutron flux/spectrum has been monitored with a BF$$_{3}$$ proportional counter, and the relative measurement has been normalized to the well-known standard capture cross section value for the $$^{99}$$Tc (n, $$gamma$$) $$^{100}$$Tc reaction at 0.0253 eV. Self-shielding corrections, especially near the resonance peaks, were made by the calculations with the MCNP code. Although the experimental data measured by Chou et al with a lead slowing-down spectrometer are higher in general, the energy dependency is similar to the present measurement. The evaluated data in ENDF/B-VI and JENDL-3.2 are higher near the resonances at 5.6 and 20 eV and above several 100 eV. A lead slowing-down spectrometer was installed coupled to a 46 MeV electron linac at the Research Reactor Institute, Kyoto university (KURRI). Characteristics of the Kyoto University Lead Slowing-down Spectrometer (KULS) were measured and (1)the relation between neutron slowing-down time t($$mu$$s) and energy E(keV) (E=190/t$$^{2}$$ in Bi hole and E=156/t$$^{2}$$ in Pb hole) and (2)the energy resolution ($$sim$$40% in Bi and Pb holes) were experimentally investigated. (3)The neutron energy spectrum in the KULS was also measured by the neutron TOF method. The results obtained by the MCNP code were in general agreement with these experimental ones.

JAEA Reports

Measurement of neutron capture cross sections of Tc-99

*

JNC-TJ9400 2000-008, 61 Pages, 2000/02

JNC-TJ9400-2000-008.pdf:2.5MB

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.

JAEA Reports

Apparent diffusion coefficients of uranium, neptunium and technetium in compacted bentonite under reducing conditions

*; *; Ueda, Shinzo*; Shibata, Masahiro

JNC-TN8400 99-069, 41 Pages, 1999/11

JNC-TN8400-99-069.pdf:1.62MB

As a part of the evaluation for the sorption phenomena of nuclides in compacted bentonite, apparent diffusivities for uranium, neptunium and technetium that are redox-sensitive elements, were measured under reducing conditions. Bentonite used was a sodium bentonite, Kunigel V1. Apparent diffusivities were measured by using in-diffusion method (concentration profile method), under the conditions with varying dry densities of compacted bentonite and sorts of the solution used for water saturation of bentonite in diffusion experiments. As a result of the measurements, following ranges of values for apparent diffusivities were acquired. ...

JAEA Reports

Analysis of americium, plutonium and technetium solubility in groundwater

Takeda, Seiji

JAERI-Research 99-047, 71 Pages, 1999/08

JAERI-Research-99-047.pdf:3.53MB

no abstracts in English

JAEA Reports

Consideration on thermodynamic data for predicting solubility and chemical species of elements in groundwater, 1; Tc, U, Am

Yamaguchi, Tetsuji; Takeda, Seiji

JAERI-Data/Code 99-001, 74 Pages, 1999/01

JAERI-Data-Code-99-001.pdf:2.65MB

no abstracts in English

Journal Articles

Solvent extraction behavior of hexachlorotechnetate(IV) ion in the HCl-TBP system

Watanabe, Satoshi; Hashimoto, Kazuyuki

Journal of Radioanalytical and Nuclear Chemistry, 239(2), p.391 - 395, 1999/00

 Times Cited Count:1 Percentile:86.34(Chemistry, Analytical)

no abstracts in English

67 (Records 1-20 displayed on this page)