Y. Kasamatsu, K. Toyomura, N. Shiohara, T. Yokokita, Y. Komori, A. Kino, T. Yoshimura, N. Takahashi, H. Haba, Y. Kudou, H. Kikunaga, T. Mitsugashira, T. Ohtsuki, K. Takamiya, A. Shinohara
cle measurement is required to be performed. Herein, we propose a new protocol for rapid preparation of coprecipitates of superheavy elements with Sm hydroxide. The coprecipitation behaviors of Zr, Hf, and Th (homologues of element 104, Rf) with Sm hydroxide in aqueous ammonia (NH3) and sodium hydroxide (NaOH) solutions were investigated by the conventional suction filtration method using 88 Zr, 175 Hf, and 228 Th radiotracers. The precipitation yields obtained by employing an aging time of only 10 s were consistent with those obtained after aging for 10 min, suggesting the rapid chemical reactions in the present coprecipitation. Approximately 100% coprecipitation yields of Zr and Hf were achieved in the solutions with dilute hydroxide concentrations, and the yields decreased with higher hydroxide concentrations. In comparison, the Th yield remained constant at almost 100% under all of the conditions. In addition, a semiautomatic suction filtration apparatus for rapid preparation of precipitated samples was developed and evaluated using the short-lived isotopes 89m,g Zr and 173 Hf, which were transported online from the nuclear reaction chamber by a He/KCl gas-jet system. Using this apparatus, sample preparation was completed within 80–120 s, and precipitation yields consistent with those determined on the basis of the manual method were obtained, suggesting the applicability of the present method to Rf experiment.
{"title":"Coprecipitation Behaviors of Zr, Hf, and Th with Sm Hydroxide for Chemical Study of Element 104, Rf","authors":"Y. Kasamatsu, K. Toyomura, N. Shiohara, T. Yokokita, Y. Komori, A. Kino, T. Yoshimura, N. Takahashi, H. Haba, Y. Kudou, H. Kikunaga, T. Mitsugashira, T. Ohtsuki, K. Takamiya, A. Shinohara","doi":"10.14494/JNRS.14.7","DOIUrl":"https://doi.org/10.14494/JNRS.14.7","url":null,"abstract":"cle measurement is required to be performed. Herein, we propose a new protocol for rapid preparation of coprecipitates of superheavy elements with Sm hydroxide. The coprecipitation behaviors of Zr, Hf, and Th (homologues of element 104, Rf) with Sm hydroxide in aqueous ammonia (NH3) and sodium hydroxide (NaOH) solutions were investigated by the conventional suction filtration method using 88 Zr, 175 Hf, and 228 Th radiotracers. The precipitation yields obtained by employing an aging time of only 10 s were consistent with those obtained after aging for 10 min, suggesting the rapid chemical reactions in the present coprecipitation. Approximately 100% coprecipitation yields of Zr and Hf were achieved in the solutions with dilute hydroxide concentrations, and the yields decreased with higher hydroxide concentrations. In comparison, the Th yield remained constant at almost 100% under all of the conditions. In addition, a semiautomatic suction filtration apparatus for rapid preparation of precipitated samples was developed and evaluated using the short-lived isotopes 89m,g Zr and 173 Hf, which were transported online from the nuclear reaction chamber by a He/KCl gas-jet system. Using this apparatus, sample preparation was completed within 80–120 s, and precipitation yields consistent with those determined on the basis of the manual method were obtained, suggesting the applicability of the present method to Rf experiment.","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"58 1","pages":"7-11"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83355204","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Radiochemical Verification Technologies for the Detection of Nuclear Explosions – Recent Developments in Radionuclide Monitoring with the Comprehensive Nuclear-Test-Ban Treaty –","authors":"Lisa Kokaji, N. Shinohara","doi":"10.14494/JNRS.14.R1","DOIUrl":"https://doi.org/10.14494/JNRS.14.R1","url":null,"abstract":"","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73179543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cerium(IV) tellurium molybdate was prepared as a new gel bed for chromatographic 99 Mo/ 99m Tc generator. The gel material prepared with the optimum conditions was characterized with IR spectroscopy, thermal analysis, XRD, EDX and FESEM. The highest precipitation yield of 99 Mo within the formed gel was found to be 97.6 % at a Ce:Te:Mo molar ratio of 1:0.2:1. The prepared 99 Mo/ 99m Tc chromatographic column based on Ce(IV) tellurium molybdate gel bed showed a good performance. The 99m Tc elution yield was 77.8±3.0 % with a radionuclidic purity of ≥ 99.99 %, radiochemical purity of 96.5±1.3 % (as 99m TcO 4- ) and pH-value in the range of 5-7. Molybdenum and cerium levels in 99m Tc eluates did not exceed 1 and 0.3 ppm, respectively, while no tellurium was detected.
{"title":"Preparation and characterization of cerium(IV) tellurium molybdate gel and its application as a bed for chromatographic 99Mo/99mTc generator","authors":"M. El-Amir, M. Mostafa, H. Ramadan","doi":"10.14494/JNRS.14.1","DOIUrl":"https://doi.org/10.14494/JNRS.14.1","url":null,"abstract":"Cerium(IV) tellurium molybdate was prepared as a new gel bed for chromatographic 99 Mo/ 99m Tc generator. The gel material prepared with the optimum conditions was characterized with IR spectroscopy, thermal analysis, XRD, EDX and FESEM. The highest precipitation yield of 99 Mo within the formed gel was found to be 97.6 % at a Ce:Te:Mo molar ratio of 1:0.2:1. The prepared 99 Mo/ 99m Tc chromatographic column based on Ce(IV) tellurium molybdate gel bed showed a good performance. The 99m Tc elution yield was 77.8±3.0 % with a radionuclidic purity of ≥ 99.99 %, radiochemical purity of 96.5±1.3 % (as 99m TcO 4- ) and pH-value in the range of 5-7. Molybdenum and cerium levels in 99m Tc eluates did not exceed 1 and 0.3 ppm, respectively, while no tellurium was detected.","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"4 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81164077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the main concerns related to the disposal of high– level radioactive liquid waste (HLLW) generated after reprocessing of spent nuclear fuel is related to the presence within this waste of long-lived radionuclides (LLRNs). The LLRNs in the spent nuclear fuels are mostly the so-called minor actinides (neptunium (Np), americium (Am) and curium (Cm)) and certain fission products. Transmutation of LLRNs to short-lived or stable isotopes represents a viable nuclear waste management strategy to drastically reduce the time and space requirements for a geological repository of the remaining waste. To be able to destroy LLRNs in a transmutation process they must be separated from the rest of the HLLW. Therefore, the concept of partitioning and transmutation (P&T) has been proposed for treatment of HLLW. 1-3 The P&T concept imposes highly-set demands on recovery yields and decontamination factors of the separated species. In this context, there has been considerable interest in amide extractants for the extraction of
{"title":"Extraction of Europium(III) and Cobalt(II) by N,N,N’,N’-Tetraoctyldiglycolamide and N,N,N’,N’-Tetrahexyldiglycolamide from Aqueous Acid Solutions","authors":"E. Metwally, A. S. Saleh, H. El-naggar","doi":"10.14494/JNRS.13.1","DOIUrl":"https://doi.org/10.14494/JNRS.13.1","url":null,"abstract":"One of the main concerns related to the disposal of high– level radioactive liquid waste (HLLW) generated after reprocessing of spent nuclear fuel is related to the presence within this waste of long-lived radionuclides (LLRNs). The LLRNs in the spent nuclear fuels are mostly the so-called minor actinides (neptunium (Np), americium (Am) and curium (Cm)) and certain fission products. Transmutation of LLRNs to short-lived or stable isotopes represents a viable nuclear waste management strategy to drastically reduce the time and space requirements for a geological repository of the remaining waste. To be able to destroy LLRNs in a transmutation process they must be separated from the rest of the HLLW. Therefore, the concept of partitioning and transmutation (P&T) has been proposed for treatment of HLLW. 1-3 The P&T concept imposes highly-set demands on recovery yields and decontamination factors of the separated species. In this context, there has been considerable interest in amide extractants for the extraction of","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"47 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72789757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ryo Ogiso, Y. Sakai, S. Onaka, T. Nakamoto, T. Takayama, Masashi Takahashi
A number of Fe-Mössbauer spectroscopic investigations of mixed-valence trinuclear iron carboxylate cluster complexes with a triangle array of iron cations (Fe, Fe, Fe) have been intensively carried out by many researchers; the general chemical formula is Fe3O(R-COO)6L3· nS, where R-COO is a carboxylate anion, L, a ligand, and S, a crystalline solvated molecule (n = 0, 1, 2, 3...). The cluster molecular structure is depicted in Figure 1. In such cluster complexes, much intensive attention has been paid to the valence-detrapping (valenceaveraging) through the electronic interactions among three iron cations. The first pioneering observation of valence-detrapping by Fe-Mössbauer spectroscopy was reported in 1984 by Hendrickson’s group, who revealed that one set of quadrupole doublet ascribing to the detrapping valence of Fe was measured in Fe3O(CH3COO)6(C5H5N)3·C5H5N at room temperature, while two separate sets of doublet due to Fe and Fe in a valence-trapped state below 100 K. After that, a lot of trinuclear iron carboxylate complexes have been so far studied using Mössbauer techniques and there have been many interesting articles, most of which were about the valence-detrapping phenomena among three iron cations. As a rare case, Sato et al. reported that valence-detrapping between one Fe and one Fe was observed at higher temperature for Fe3O(CH2ClCOO)6(H2O)3·3H2O. This partial valence-detrapping, in which one of two Fe ions participates, was explained from the sites of two Fe ions being not strictly equivalent. In the present research, we measured temperature-dependent Fe-Mössbauer spectra of a novel mixed-valence trinuclear heterometal pentafluorobenzoate cluster complex, CrFeFe O(C6F5COO)6(C5H5N)3·0.5C5H5N·CH2Cl2 (1) synthesized by a modified method of our previous preparation procedure for Fe3 O(C6F5COO)6(C5H5N)3·CH2Cl2 (2). The purpose of this work is to examine whether the valence detrapping occurs or not, and what cations participate in the detrapping if it occurs. 2. Experimental
{"title":"Observation of Iron-valence Detrapping in Mixed-valence Trinuclear Heterometal Pentafluorobenzoate Cluster Complex Cr3+Fe3+Fe2+O(C6F5COO)6(C5H5N)3·0.5C5H5N·CH2Cl2 by 57Fe-Mössbauer Spectroscopy","authors":"Ryo Ogiso, Y. Sakai, S. Onaka, T. Nakamoto, T. Takayama, Masashi Takahashi","doi":"10.14494/JNRS.13.N1","DOIUrl":"https://doi.org/10.14494/JNRS.13.N1","url":null,"abstract":"A number of Fe-Mössbauer spectroscopic investigations of mixed-valence trinuclear iron carboxylate cluster complexes with a triangle array of iron cations (Fe, Fe, Fe) have been intensively carried out by many researchers; the general chemical formula is Fe3O(R-COO)6L3· nS, where R-COO is a carboxylate anion, L, a ligand, and S, a crystalline solvated molecule (n = 0, 1, 2, 3...). The cluster molecular structure is depicted in Figure 1. In such cluster complexes, much intensive attention has been paid to the valence-detrapping (valenceaveraging) through the electronic interactions among three iron cations. The first pioneering observation of valence-detrapping by Fe-Mössbauer spectroscopy was reported in 1984 by Hendrickson’s group, who revealed that one set of quadrupole doublet ascribing to the detrapping valence of Fe was measured in Fe3O(CH3COO)6(C5H5N)3·C5H5N at room temperature, while two separate sets of doublet due to Fe and Fe in a valence-trapped state below 100 K. After that, a lot of trinuclear iron carboxylate complexes have been so far studied using Mössbauer techniques and there have been many interesting articles, most of which were about the valence-detrapping phenomena among three iron cations. As a rare case, Sato et al. reported that valence-detrapping between one Fe and one Fe was observed at higher temperature for Fe3O(CH2ClCOO)6(H2O)3·3H2O. This partial valence-detrapping, in which one of two Fe ions participates, was explained from the sites of two Fe ions being not strictly equivalent. In the present research, we measured temperature-dependent Fe-Mössbauer spectra of a novel mixed-valence trinuclear heterometal pentafluorobenzoate cluster complex, CrFeFe O(C6F5COO)6(C5H5N)3·0.5C5H5N·CH2Cl2 (1) synthesized by a modified method of our previous preparation procedure for Fe3 O(C6F5COO)6(C5H5N)3·CH2Cl2 (2). The purpose of this work is to examine whether the valence detrapping occurs or not, and what cations participate in the detrapping if it occurs. 2. Experimental","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75083697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Kasamatsu, A. Toyoshima, H. Toume, K. Tsukada, M. Asai, H. Haba, Y. Nagame
{"title":"Adsorption Behavior of 95Nb and 179Ta as Homologues of Element 105, Db, on Cation Exchanger in HF/HNO3 Solution","authors":"Y. Kasamatsu, A. Toyoshima, H. Toume, K. Tsukada, M. Asai, H. Haba, Y. Nagame","doi":"10.14494/JNRS.13.9","DOIUrl":"https://doi.org/10.14494/JNRS.13.9","url":null,"abstract":"","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"30 1","pages":"9-12"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84380770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Asai, Y. Kaneya, Tetsuya K. Sato, K. Tsukada, K. Ooe, N. Sato, A. Toyoshima
The accident of the Fukushima Daiichi Nuclear Power Plant dispersed a huge amount of radionuclides in the natural environment, and part of them were deposited on the ground surface in the extensive region of east Japan. Assessments of the deposition densities of radionuclides and their geographical distributions provide important quantitative bases for estimations of radiation exposures of the residents, transfer of radionuclides into agricultural products, costs of decontaminations, etc. The Japanese government in collaboration with a few hundreds of researchers in universities and associations carried out detailed measurements of radionuclides deposited on soil over the whole area of Fukushima prefecture. Independent of this work, we carried out measurements of radionuclides in soil samples collected in the north and east area of Ibaraki prefecture and in the east area of Tochigi prefecture. The soil samples were collected on May 21–22 and June 22 in 2011, and γ rays originating from the β decay of I, Cs, and Cs were observed with Ge detectors, whose details are described in a separate paper. To measure radioactivities in soil with a Ge detector, we have to know γ-ray detection efficiencies of the Ge detector for soil samples. Typically soil samples have a large volume and density. Thus, to determine the efficiencies of Ge detectors, it is necessary to prepare the standard soil sample which contains a known amount of radionuclides and whose shape, density, and elemental contents are approximately the same as those of soil samples. At first, we used a standard soil sample distributed by IAEA to measure the efficiencies. This soil sample contains 4.0–60 Bq kg of Am, Cd, Cs, Cs, Mn, and Co. However, these radioactivity concentrations were too weak to determine the detector efficiencies precisely. Moreover, this standard source does not contain radionuclides which emit γ rays with energies at the range of 90–600 keV. This makes it difficult to determine the efficiency for the 364 keV γ ray of I. A mixed γ-ray standard source which resembles soil samples in shape, density, and elemental contents is commercially available. However, typically it does not contain I and Cs. The efficiency at 364 keV for I is extracted from the efficiency calibration curve determined by using γ rays of, e.g., Hg (279 keV), Cr (320 keV), Sn (392 keV), Sr (514 keV), and Cs (662 keV). However, these radionuclides except Cs are not always available because of their short half-lives. For Cs, even if the efficiency calibration curve is determined precisely, one has to take account of the influence of the cascade summing effect which reduces or increases observed γ-ray peak counts, especially when the sample is placed at a close source-to-detector distance. For point sources, correction factors for the cascade summing effect are easily calculated using total efficiencies and full-energy peak efficiencies of Ge detectors determined experimentally. For volume sources, however, th
{"title":"Efficiency Calibration of Ge Detector for 131I and 134Cs in Soil Samples and a Simplified Calculation of Cascade Summing Corrections for Volume Source","authors":"M. Asai, Y. Kaneya, Tetsuya K. Sato, K. Tsukada, K. Ooe, N. Sato, A. Toyoshima","doi":"10.14494/JNRS.12.5","DOIUrl":"https://doi.org/10.14494/JNRS.12.5","url":null,"abstract":"The accident of the Fukushima Daiichi Nuclear Power Plant dispersed a huge amount of radionuclides in the natural environment, and part of them were deposited on the ground surface in the extensive region of east Japan. Assessments of the deposition densities of radionuclides and their geographical distributions provide important quantitative bases for estimations of radiation exposures of the residents, transfer of radionuclides into agricultural products, costs of decontaminations, etc. The Japanese government in collaboration with a few hundreds of researchers in universities and associations carried out detailed measurements of radionuclides deposited on soil over the whole area of Fukushima prefecture. Independent of this work, we carried out measurements of radionuclides in soil samples collected in the north and east area of Ibaraki prefecture and in the east area of Tochigi prefecture. The soil samples were collected on May 21–22 and June 22 in 2011, and γ rays originating from the β decay of I, Cs, and Cs were observed with Ge detectors, whose details are described in a separate paper. To measure radioactivities in soil with a Ge detector, we have to know γ-ray detection efficiencies of the Ge detector for soil samples. Typically soil samples have a large volume and density. Thus, to determine the efficiencies of Ge detectors, it is necessary to prepare the standard soil sample which contains a known amount of radionuclides and whose shape, density, and elemental contents are approximately the same as those of soil samples. At first, we used a standard soil sample distributed by IAEA to measure the efficiencies. This soil sample contains 4.0–60 Bq kg of Am, Cd, Cs, Cs, Mn, and Co. However, these radioactivity concentrations were too weak to determine the detector efficiencies precisely. Moreover, this standard source does not contain radionuclides which emit γ rays with energies at the range of 90–600 keV. This makes it difficult to determine the efficiency for the 364 keV γ ray of I. A mixed γ-ray standard source which resembles soil samples in shape, density, and elemental contents is commercially available. However, typically it does not contain I and Cs. The efficiency at 364 keV for I is extracted from the efficiency calibration curve determined by using γ rays of, e.g., Hg (279 keV), Cr (320 keV), Sn (392 keV), Sr (514 keV), and Cs (662 keV). However, these radionuclides except Cs are not always available because of their short half-lives. For Cs, even if the efficiency calibration curve is determined precisely, one has to take account of the influence of the cascade summing effect which reduces or increases observed γ-ray peak counts, especially when the sample is placed at a close source-to-detector distance. For point sources, correction factors for the cascade summing effect are easily calculated using total efficiencies and full-energy peak efficiencies of Ge detectors determined experimentally. For volume sources, however, th","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"16 1","pages":"5-10"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77642376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chemistry of the transactinide elements with atomic numbers (Z) ≥ 104 is one of the most fascinating and challenging subjects in the research field of nuclear and radiochemistry. At present, the elements up to element 118 are reported to be produced in heavy-ion-induced nuclear reactions. 2 The position of these elements at the Periodic Table is of fundamental importance. Pioneering chemical works performed with a few of atoms have thus far experimentally verified to place the transactinide elements on respective positions at the Periodic Table (see Figure 1). Rutherfordium (Rf) through hassium (Hs) 3, 4 and copernicium (Cn) are arranged on the groups 4 to 8 and 12 in the newly appearing 6d transition series, respectively. Very recently, chemical behavior of element 114 was reported to deviate from the systematic trend in that of lighter group-14 elements although further confirmation is necessary. It is of special interest to study chemical properties of the transactinide elements in detail to elucidate the influence of increasingly strong relativistic effects. Relativistic mass increase of electrons due to its velocity approaching to the speed of light enforces the contraction and stabilization of s and p1/2 orbitals. The increased screening by these contracted orbitals for a positive nuclear charge makes outer p3/2, d, and f orbitals expanded and destabilized. Relativistic contribution also comes from the spin-orbit splitting of electron orbitals Chemical Studies of Rutherfordium (Rf) and Nobelium (No) on an Atom-at-a-time Scale
{"title":"Chemical Studies of Rutherfordium (Rf) and Nobelium (No) on an Atom-at-a-time Scale","authors":"A. Toyoshima","doi":"10.14494/JNRS.12.A1","DOIUrl":"https://doi.org/10.14494/JNRS.12.A1","url":null,"abstract":"Chemistry of the transactinide elements with atomic numbers (Z) ≥ 104 is one of the most fascinating and challenging subjects in the research field of nuclear and radiochemistry. At present, the elements up to element 118 are reported to be produced in heavy-ion-induced nuclear reactions. 2 The position of these elements at the Periodic Table is of fundamental importance. Pioneering chemical works performed with a few of atoms have thus far experimentally verified to place the transactinide elements on respective positions at the Periodic Table (see Figure 1). Rutherfordium (Rf) through hassium (Hs) 3, 4 and copernicium (Cn) are arranged on the groups 4 to 8 and 12 in the newly appearing 6d transition series, respectively. Very recently, chemical behavior of element 114 was reported to deviate from the systematic trend in that of lighter group-14 elements although further confirmation is necessary. It is of special interest to study chemical properties of the transactinide elements in detail to elucidate the influence of increasingly strong relativistic effects. Relativistic mass increase of electrons due to its velocity approaching to the speed of light enforces the contraction and stabilization of s and p1/2 orbitals. The increased screening by these contracted orbitals for a positive nuclear charge makes outer p3/2, d, and f orbitals expanded and destabilized. Relativistic contribution also comes from the spin-orbit splitting of electron orbitals Chemical Studies of Rutherfordium (Rf) and Nobelium (No) on an Atom-at-a-time Scale","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90778164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For the development of sulfide reprocessing process for spent nuclear fuel, behaviors of fission products (FP) in the sulfide reprocessing process was analyzed by the use of their radioactive tracers. First,the FP tracer doped U3O8 was prepared by two stage heat-treatments using 152Eu,141Ce,140Ba,137Cs,103Ru,95Zr and 90Zr tracers.Then the FP tracer doped U3O8 was sulfurized by CS2 at 573,673 and 773 K followed by dissolving the sample into nitric acid.The dissolution ratios were obtained from γ-ray spectrometry of the tracers.The results are summarized as follows; 1) Dissolution ratio of Eu was high compared with that of U,and it increased with increasing sulfurization temperature,2) Cerium and Zr showed very low dissolution ratios as well as that of U,3) Dissolution ratio of alkali and alkaline earth elements was very high for all temperatures,4) Ruthenium showed very low dissolution ratio (c.a.1%),because of the formation of very stable sulfide,5)The experimental results correspond well with the thermodynamic consideration.
{"title":"Behavior of Fission Products in Sulfide Reprocessing Process","authors":"A. Kirishima, Yuuki Amano, N. Sato","doi":"10.14494/JNRS.12.1","DOIUrl":"https://doi.org/10.14494/JNRS.12.1","url":null,"abstract":"For the development of sulfide reprocessing process for spent nuclear fuel, behaviors of fission products (FP) in the sulfide reprocessing process was analyzed by the use of their radioactive tracers. First,the FP tracer doped U3O8 was prepared by two stage heat-treatments using 152Eu,141Ce,140Ba,137Cs,103Ru,95Zr and 90Zr tracers.Then the FP tracer doped U3O8 was sulfurized by CS2 at 573,673 and 773 K followed by dissolving the sample into nitric acid.The dissolution ratios were obtained from γ-ray spectrometry of the tracers.The results are summarized as follows; 1) Dissolution ratio of Eu was high compared with that of U,and it increased with increasing sulfurization temperature,2) Cerium and Zr showed very low dissolution ratios as well as that of U,3) Dissolution ratio of alkali and alkaline earth elements was very high for all temperatures,4) Ruthenium showed very low dissolution ratio (c.a.1%),because of the formation of very stable sulfide,5)The experimental results correspond well with the thermodynamic consideration.","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"1 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75161902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present investigation, systematic study of synergistic effects of phosphine oxides and tributyl phosphate on the extraction of Ag (I) from aqueous nitrate medium with N-(thioacetyl) bezamide into n-butanol is being reported. The ligand was synthesized and cha racter ized in our laborator y. Temperature dependence of extraction equilibrium have been studied in order to evaluate the thermodynamic parameters responsible for the extraction. Finally, IR data were used to support the extraction mechanism. 2. Experimental 2.1. Reagents and instrument. The chelating ligand (Nthio acetyl) benzamide was synthesised by the reaction of thioacetamide and benzoylchloride, derived form benzoic acid, which were obtained from Aldrich, USA. The donor reagents used in this work e.g tri-butyl phosphine oxide (TBPO), triphenyl phosphine oxide (TPPO), tri-butyl phosphate (TBP), were also collected from Aldrich; USA. The solvents were purified by standard procedures. All other reagents used were of A.R. grade. A stock solution of silver was prepared by dissolving A.R. AgNO3 in deionized water and a working stock was prepared by appropriate dilution. In order to spike the solution, an appropriate volume of stock solution of Ag(I) was mixed, with few drops of tracer solution containing, 110m Ag as
本文系统研究了磷氧化物和磷酸三丁酯对硝酸水溶液中N-(硫乙酰基)bezamide萃取银(I)制备正丁醇的协同作用。在实验室合成了配体并对其进行了表征。研究了萃取平衡对温度的依赖关系，以评价萃取的热力学参数。最后，利用红外数据支持提取机制。2. 2.1实验。试剂和仪器。以美国Aldrich公司的苯甲酸为原料，以硫代乙酰胺和苯甲酰氯为原料，合成了螯合配体(Nthio acetyl)苯甲酰胺。本研究使用的供体试剂如三丁基氧化膦(TBPO)、三苯基氧化膦(TPPO)、三丁基磷酸(TBP)也收集自Aldrich;美国。溶剂按标准程序纯化。其他所用试剂均为a.r级。将AgNO3溶解于去离子水中制备银原液，适当稀释后制备工作原液。将适量的Ag(I)原液与少量含110 μ m Ag的示踪液混合，使溶液呈尖刺状
{"title":"Radiotracer Study of Synergistic Effects of Organophosphorus Compounds on the Extraction of Silver by N-(thio acetyl) benzamide into n-butanol","authors":"P. Dey, S. Basu","doi":"10.14494/JNRS.11.13","DOIUrl":"https://doi.org/10.14494/JNRS.11.13","url":null,"abstract":"In the present investigation, systematic study of synergistic effects of phosphine oxides and tributyl phosphate on the extraction of Ag (I) from aqueous nitrate medium with N-(thioacetyl) bezamide into n-butanol is being reported. The ligand was synthesized and cha racter ized in our laborator y. Temperature dependence of extraction equilibrium have been studied in order to evaluate the thermodynamic parameters responsible for the extraction. Finally, IR data were used to support the extraction mechanism. 2. Experimental 2.1. Reagents and instrument. The chelating ligand (Nthio acetyl) benzamide was synthesised by the reaction of thioacetamide and benzoylchloride, derived form benzoic acid, which were obtained from Aldrich, USA. The donor reagents used in this work e.g tri-butyl phosphine oxide (TBPO), triphenyl phosphine oxide (TPPO), tri-butyl phosphate (TBP), were also collected from Aldrich; USA. The solvents were purified by standard procedures. All other reagents used were of A.R. grade. A stock solution of silver was prepared by dissolving A.R. AgNO3 in deionized water and a working stock was prepared by appropriate dilution. In order to spike the solution, an appropriate volume of stock solution of Ag(I) was mixed, with few drops of tracer solution containing, 110m Ag as","PeriodicalId":16569,"journal":{"name":"Journal of nuclear and radiochemical sciences","volume":"7 1","pages":"13-18"},"PeriodicalIF":0.0,"publicationDate":"2010-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74316805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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