(α, αxn) and (α, 2pxn) reactions on93Nb

Target foil stacks of niobium were bombarded with beams of alpha particles at incident energies ranging from 0 to 90 MeV. Cumulative cross sections for the production of^95(m+g)Nb,^92mNb,^91mNb and^90(m+g)Nb were determined by semiconductor gamma-spectrometry of the residual activity of stacked foils. On the basis of the cumulative cross sections, the thick target yields and saturation production rates of niobium isotopes have been evaluated.     

Separation of182Ta from biological material by precipitating it as tantalum phosphate

The method of the separation of¹⁸²Ta from urine and stool by precipitating as tantalum phosphate was elaborated. The conditions of Ta phosphate precipitation as well as coprecipitation of⁴⁵Ca,¹⁰⁶Ru,¹⁴⁴Ce,¹⁴⁷Pm,¹⁵²Eu,⁶⁰Co,⁹⁰Sr,⁹⁰Y,⁹⁵ Zr,⁹⁵Nb and U were studied. The results show that tantalum can be separated from all macrocomponents of the mineralized biological material and from the great number of radionuclides which can be present in the sample.     

Study of the state of95Zr+95Nb in aqueous solutions

The adsorption on paraffine and polyethylene and the paper chromatography in aqueous solutions in the pH range of 2–12 were used for the study of the behaviour of⁹⁵Zr and⁹⁵Nb. The effect of complexing ions (SO ₄ ^2? and CO ₃ ^2? ) was studied in the same pH range. The constants of hydrolysis and the composition of hydrolytic species of⁹⁵Zr in the solution containing sulphate ions were determined in the pH range of 1–2. The paper chromatography was used for the control of the purity of⁹⁵Zr after an extractive separation from⁹⁵Nb with α-benzoinoxime. The possibility of studying the extraction processes of Zr (without its previous separation from Nb) by reversed phase chromatography is shown. Conditions for the formation of polynuclear compounds of Zr and Nb and their influence on the extraction separation in nitrate media were studied.     

Preparation of99Mo,132Te isotopes and99mTc,132I generators

Adsorption and desorption of⁹⁵Zr−⁹⁵Nb,⁹⁹Mo,¹⁰³Ru,¹³²Te and²³⁹Np in a HCl-alumina system were studied in order to purify⁹⁹Mo and¹³²Te obtained by the cation-exchange separation of fission products and to prepare highly pure^99mTc and¹³²I generators.⁹⁹Mo and¹³²Te, of which radionuclidic purity was over 99.99% and 99.999%, respectively, could be obtained by passing the cation-exchange separated Mo and Te fractions through alumina columns, by washing with HCl and finally by eluting⁹⁹Mo with 1M NH₄OH and¹³²Te with 3M NaOH. In order to raise the recovery of⁹⁹Mo and¹³²Te from the alumina columns, they should be eluted as quickly as possible after the adsorption. The direct use of the alumina column containing⁹⁹Mo or¹³²Te as the generator allowed milking of^99mTc or¹³²I, of which radionuclidic purity was over 99.999%. Milking yields of^99mTc with 0.1M HCl and¹³²I with 0.01M NH₄OH were 77% and 90%, respectively. The latter value was much higher than that in usual performance of the generator.     

Independent isomeric yield ratios of 95m,gNb in the natMo(γ, pxn) and natZr(p,xn) reactions

The independent isomeric yield ratios of ^95m,gNb from the ^natMo(γ, pxn) reactions with bremsstrahlung end-point energies of 45, 50, 55, 60, and 70 MeV were determined by an activation and an off-line γ-ray spectrometric technique at the Pohang accelerator laboratory (PAL), Korea. The isomeric yield ratios of ^95m,gNb from the ^natZr(p, xn) reactions were also determined in eight different proton energies within 19.4–44.7 MeV by a stacked-foil activation and an off-line γ-ray spectrometric technique using the MC-50 cyclotron of Korea Institute of Radiological and Medical Sciences (KIRAMS), Korea. The measured isomeric yield ratios of ^95m,gNb from the present work and the literature data in the ^natMo(γ, pxn) and ^natZr(p, xn) reactions were compared with the similar literature data in the ^natMo(p, αxn) reactions. It was found that the isomeric yield ratio of ^95m,gNb increases with projectile energy, which indicate the effect of excitation energy. However, at the same excitation energy, the isomeric yield ratios of ^95m,gNb in the ^natZr(p, xn) and ^natMo(p, αxn) reactions are higher than those in the ^natMo(γ, pxn) reaction, which indicates the role of input angular momentum. The isomeric yield ratios of ^95m,gNb in the ^natMo(γ, pxn), ^natZr(p, xn), and ^natMo(p, αxn) reactions were also calculated using computer code TALYS 1.4. The calculated isomeric yield ratios of ^95m,gNb from three reactions increase with excitation energy. However, in all the three reactions, the calculated values are significantly higher than the experimental data.     

Dünnschichtchromatographie an Salzen von Heteropolysäuren

Zusammenfassung In Fortsetzung früherer Arbeiten wurde die Verwendbarkeit von Oxingermanododekamolybdat und Pyridingermanododekamolybdat als Dünnschichtträgermaterial bei der Auftrennung von Uran-Spaltprodukten untersucht. Eine spezifische Abtrennung des Cäsiums von den Spaltprodukten⁹⁵Zr/⁹⁵Nb,¹⁰⁶Ru,⁹⁰Sr/⁹⁰Y und¹⁴⁴Ce mit Hilfe von 0,01-m Ammoniumacetat-ÄDTA bzw. 0,001-m Ammoniumacetat-ÄDTA wurde durchgeführt.

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Summary In continuation of previous studies, an investigation was made of the possibility of employing oxine germanomolybdate and pyridine germanomolybdate as thin layer carrying material in the separation of uranium fission products. A specific separation of cesium from the fission products⁸⁵Zr/⁹⁵Nb,¹⁰⁶Ru,⁹⁰Sr/⁹⁰Y,¹⁴⁴Ce was carried out with the aid of 0,01M ammonium acetate-EDTA or 0,001M ammonium acetate-EDTA.

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Résumé Faisant suite au travail précédent, on a étudié expérimentalement les possibilités d'application du germanomolybdate d'oxine et de pyridinium comme substance-support pour couche mince dans le cas de la séparation des produits de fission de l'uranium. On a effectué une séparation spécifique du césium des produits de fission⁸⁵Zr/⁹⁵Nb,¹⁶⁶Ru,⁹⁰Sr/⁹⁰Y et¹⁴⁴Ce par le système EDTA-acétate d'ammonium 0,01M ou EDTA-acétate d'ammonium 0,001M.

     

Rapid separation of niobium-95 from zirconium-95 by solvent extraction with α-benzoinoxime

A solvent extraction method is presented for the separation of⁹⁵Nb from⁹⁵Zr.⁹⁵Nb is extracted quantitatively into a chloroform solution of α-benzoinoxime from 5N hydrochloric acid solution. By following the recommended procedure, a separation factor higher than 10⁴ is achieved.⁹⁵Nb can be back-extracted into concentrated hydrochloric acid. The radiochemical purity of the⁹⁵Nb separated has been ascertained by half-life and γ-ray energy measurements. The whole procedure takes less than 20 min.     

Versuche zur Trennung von Radionukliden durch Zonen anorganischer Ionenaustauscher auf Filterpapierstreifen

Zusammenfassung An zahlreichen anorganischen Ionenaustauschern, die in Form schmaler Zonen auf Papierstreifen präpariert worden waren, wurde in verschiedenen wäßrigen Medien nach Art der aufsteigenden Papier-Chromatographie das Austauschverhalten einiger Radioisotope untersucht. Aus vielen Einzelresultaten ergaben sich Trennmöglichkeiten für Nuklidgemische mit Hilfe einer, zweier oder dreier Austauscherzonen. Weiterhin konnte ein qualitatives Trennschema für das Spaltproduktgemisch ¹³⁷Cs/^137mBa, ⁹⁰Sr/⁹⁰Y, ¹⁰⁶Ru/¹⁰⁶Rh, ¹⁴⁴Ce/¹⁴⁴Pr und ⁹⁵Zr/⁹⁵Nb ausgearbeitet werden.

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Separation of radionuclides by zones of inorganic ion exchangers on filter-paper strips

A number of various inorganic ion exchangers has been prepared in the form of narrow zones on paper strips. Their exchange behaviour against some radioisotopes has been studied in different aqueous solutions using a technique similar to ascending paper chromatography. From the many results of these experiments possibilities for separating mixtures of nuclides have been derived with the aid of one, two or three zones of exchangers on the paper strips. Finally, a qualitative scheme could be worked out for separating the mixture of the fission products ¹³⁷Cs/^137mBa, ⁹⁰Sr/⁹⁰Y, ¹⁰⁶Ru/¹⁰⁶Rh, ¹⁴⁴Ce/¹⁴⁴Pr and ⁹⁵Zr/⁹⁵Nb.

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Herrn Prof. Dr. Georg Brauer zum 60. Geburtstag freundlichst gewidmet.

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Herrn Prof. Dr. W. Seelmann-Eggebert, dem Direktor des Instituts für Radiochemie im Kernforschungszentrum Karlsruhe, sei an dieser Stelle für die Überlassung von Radionuklidlösungen bestens gedankt.     

Purification of radiozirconium and the influence of accumulation of daughter radioactivity on the accuracy of its distribution measurements

The use of nuclide⁹⁵Zr as radiotracer is often unfavourably influenced by the continuous accumulation of the radioactive daughter nuclide⁹⁵Nb. The present paper gives a method showing how the daughter radioactivity can influence the value of the distribution coefficient of zirconium calculated from radioactivity measurements. A simple method of continuous purification of⁹⁵Zr, which yields a product of the required degree of purity, is also described.     

Dünnschichtchromatographie an Salzen von Heteropolysäuren

Zusammenfassung In Fortsetzung einer früheren Arbeit wurde die Verwendbarkeit von Ammoniumphosphordodekamolybdat (APM), Ammoniumgermanododekamolybdat (AGM), Oxingermanododekamolybdat (OGM), Pyridingermanododekamolybdat (PGM), Oxinsilicododekamolybdat (OSM) und Pyridinsilicododekamolybdat (PSM) für Dünnschichtchromatographie untersucht und die Abhängigkeit derR _f -Werte der Alkalimetallionen von der Laufmittelkonzentration (Ammoniumnitrat und Wasser) bestimmt. Gleichzeitig wurden Vorversuche angestellt, eine spezifische Abtrennung des Cäsiums von den Spaltprodukten⁹⁵Zr/⁹⁵Nb,¹⁰⁶Ru,⁹⁰Sr/⁹⁰Y und¹⁴⁴Ce durchzuführen.

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Summary As continuation of an earlier study, ammonium phosphododeoa molybdate (APM), ammonium germanododecamolybdate (AGM), oxinegerdodecamolybdate (OGM), pyridinegermanododecamolybdate (PGM), oxininesilicododecamolybdate (OSM), and pyridinesilicododecamolybdate (PSM) were investigated for thin layer chromatography and the relation of theR _f -values of the alkali metal ions to the concentration of the carrier concentration (ammonium nitrate and water) was determined. At the same time, preliminary studies were made with respect to a specific separation of cesium from the fission products⁹⁵Zr/⁹⁵Nb,¹⁰⁶Ru,⁹⁰Sr/⁹⁰Y and¹⁴⁴Ce.

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Résumé Comme suite à une publication antérieure, on a étudié les possibilités d'application en chromatographie en couche mince du phosphododécamolybdate d'ammonium (APM), du germanidodécamolybdate d'ammonium (AGM), du germanidodécamolybdate d'oxinium (OGM), du germanidodécamolybdate de pyridinium (PGM), du silicomolybdate d'oxinium (OSM) et du silicododécamolybdate de pyridinium, en déterminant la dépendance des valeurs duR _f des ions métalliques alcalins avec la concentration de l'éluant (nitrate d'ammonium et eau). On a commencé simultanément l'étude de la séparation spécifique du césium d'avec les produits de fission⁹⁵Zr/⁹⁵Nb,¹⁰⁶Ru,⁹⁰Sr/⁹⁰Y et¹⁴⁴Ce.

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Herrn Prof. Dr.A. A. Benedetti-Pichler mit herzlichen Wünschen zum 70. Geburtstag gewidmet.     

Excretion of biotrace elements using the multitracer technique in mice

A radioactive multitracer solution obtained from the nuclear reaction of selenium with 25 MeV/nucleon⁴⁰Ar ions was applied to the investigation of the trace elements behavior in feces and urine of mouse. The excretion rates of 23 elements, Na, K, Rb, Mg, Ca, Sr, Ga, As, Sc, V, Cr, Mn, Co, Fe, Zn, Y, Zr, Mo, Nb, Tc, Ru, Ag and In were simultaneously detected under strictly identical experimental conditions, in order to clarify the excretion behavior of the elements in mice. Fecal and urinary excretion rates of the elements in mice reached the highest value separately at 48 and 24 hours. The total excretion of Mo, Tc and Co within 96 hours were all larger, more than 60%. Accumulative excretion rates of Ca, Nb, Mg, Sr, V, Sc, Na, Cr, Fe, Ag, Mn and Zr were 60-30%. The total rates of Ru, K, As, Zn, Rb, Y, Ga and In were less than 30%, and low excretion. The main excretion pathway of Mo, Co, Mg, Fe and Ag was through urine, and Na, K, As and Rb were eliminated from the body also in urine. But fecal excretion of Tc, Nb, Sr, Y, Ru, and In were larger than urinary excretion, and Ca, Sc, Mn, Zr, Zn were eliminated from the body in feces.     

14 MeV neutron reactions producing gamma-ray emitting nuclides with half-lives below 3 seconds

Fast neutron activation analysis (FNAA) experiments were performed using a Cockroft-Walton neutron generator and a fast pneumatic rabbit system with a sample transport time of 120 ms. With this facility cyclic activations of¹⁸O, Zr, Ba and Pb leading to the short-lived reaction products¹⁵C,^90mZr,^136mBa and^207mPb were investigated. Derived from these measurements the analytical sensitivities of the involved reactions will be discussed.     

Redetermination of several half-lives

The half-live of⁴¹Ar,^80mBr,^94mNb,¹⁰¹Mo,¹⁰¹Tc,¹⁰⁹Pd,^109mPd,¹²²Sb,^123mSn,^152mEu and²³⁹Np have been measured more accurately compared to previous measurements.     

A99Mo-99mTc generator based on the use of zirconium molybdophosphate-99Mo gel

A modified⁹⁹Mo–^99mTc gel generator is described. The present generator uses an insoluble zirconium molybdophosphate (ZrMP) gel tagged with⁹⁹Mo. Molybdenum-99 is chemically combined in the gel structure and cannot be eluted from the matrix. The presence of phosphate increases the chemical stability of the gel and decreases the molybdenum breakthrough. The prepared gel is sufficiently porous to permit ready diffusion of^99mTcO ₄ ^– which can be cluted with saline in yields of up to 90%. The gel was found to contain 25.1% Mo, 21.9% Zr, and 0.7% P in a molar ratio of 1.09:1.0:0.09, respectively. The high molybdenum content of the gel allows the use of cheap, non-polluting (n, )⁹⁹Mo. The eluted^99mTc was of high purity and can be used for medical and pharmaceutical applications.     

Chemical study on the separation and purification of promethium-147

A chemical process for the separation of¹⁴⁷Nd/¹⁴⁷Pm from fission products of synthetic radioactive waste solution has been developed. The process includes: (1) denitration, (2) removal of high concentration of uranium by 30% TBP/kerosene extraction, (3) removal of⁹⁵Nb,¹⁰³Ru,¹³⁷Cs and part of⁹⁰Sr by 50% TBP/dodecane extraction, (4) separation of¹⁴⁷Nd/¹⁴⁷Pm from part of⁹⁰Sr and⁹⁵Zr by oxalic acid precipitation, and (5) removal of¹⁴⁴Ce by mixture of 0.4M D2EHPA and 0.2M TBP extraction. Experimental results indicate that the recovery of¹⁴⁷Nd/¹⁴⁷Pm in the final separated solution is about 90%. The purification of¹⁴⁷Nd and¹⁴⁷Pm from some other rare earth elements, viz.¹⁵³Sm,¹⁵⁴Eu and¹⁴⁴Ce was further investigated by using a Dowex 50W×8 ion-exchanger. Parameters of flow rate, eluent concentration and pH were examined. The results show that the recovery and radionuclide purity of¹⁴⁷Nd plus¹⁴⁷Pm under the present separation conditions are 77.8% and 98.6% for diethylenetriaminepentaacetic acid (DTPA) and 87.3% and 99.5% for nitrilotriacetic acid (NTA), respectively.     

Independent isomeric-yield ratio of 89m,gNb from 93Nb(γ, 4n), natZr(p,xn), and 89Y(α, 4n) reactions

The independent isomeric-yield ratios of ^89m,gNb for the ⁹³Nb(γ, 4n) ^89m,gNb reaction with bremsstrahlung energies of 45-, 50-, 55-, 60-, and 70-MeV were measured by the activation and the off-line γ-ray spectrometric technique at 100 MeV electron linac of the Pohang accelerator laboratory. The isomeric-yield ratios of ^89m,gNb for the ^natZr(p, xn) ^89m,gNb and the ⁸⁹Y(α, 4n) ^89m,gNb reactions were measured by using a stacked-foil activation technique with the proton energies of 19–45 MeV and alpha energies of 38.9-, 40.5-, and 42.5-MeV at the MC-50 cyclotron of Korea Institute of Radiological and Medical Sciences. The measured isomeric-yield ratio of ^89m,gNb from the ⁹³Nb(γ, 4n), ^natZr(p, xn), and ⁸⁹Y(α, 4n) reactions were compared with the similar literature data in the ⁸⁹Y(³He, 3n) reaction. It was found that the isomeric yield ratio of ^89m,gNb increases with projectile energy, which indicate the effect of excitation energy. However, for the similar compound nucleus with the same excitation energy, the isomeric-yield ratios of ^89m,gNb in the ⁸⁹Y(α, 4n) and ⁸⁹Y(³He, 3n) reactions are higher than those in the ⁹³Nb(γ, 4n) and ^natZr(p, xn) reactions, which indicates the role of input angular momentum. The isomeric-yield ratios of ^89m,gNb in the ⁹³Nb(γ, 4n), ^natZr(p, xn), ⁸⁹Y(α, 4n), and ⁸⁹Y(³He, 3n) reactions were also calculated theoretically using computer code TALYS 1.4. The theoretical isomeric-yield ratios of ^89m,gNb from four reactions increase with excitation energy. However, the theoretical value are significantly higher than the experimental data in the ⁹³Nb(γ, 4n) and ^natZr(p, xn) reactions but slightly lower or comparable in the ⁸⁹Y(α, 4n) rand ⁸⁹Y(³He, 3n) reactions.     

Preparation of a ready-for-injection radiopharmaceutical based on MIBI using99mTc from a centralized extraction generator

The state of trace concentrations of⁹⁵Zr–⁹⁵Nb and¹³⁴Cs was studied at an initial pH>13 in an uranyl triperoxidate medium using the electromigration method. OH^– ions governing the potential are adsorbed on the colloidal Nb(V)-hydroxide which leads to an increase in its negative electric charge; while⁹⁵Zr did not move during the procedure. However, the electrophoretic mobility of the¹³⁴Cs could be explained in terms of their agglomerations attributed to the interaction of Cs⁺ ions with water molecules to give larger aggregations.     

Production of99Mo and its application in nuclear medicine

Molybdenum-99 is produced in large quantities as the parent radioisotopes of^99mTc, which has been used recently in nuclear medicine. The neutron capture reaction on molybdenum and the nuclear fission of uranium are used for the large scale production of⁹⁹Mo. The products by these methods are used properly according to the objects of diagnosis. In this paper, the production of⁹⁹Mo is reviewed and the development of the production in JAERI is outlined.     

Cross-sections for formation of <Superscript>178m2</Superscript>Hf and <Superscript>179m2</Superscript>Hf through reactions on natural hafnium at neutron energy 14.8 ± 0.2 MeV

The cross sections for formation of metastable state of ¹⁷⁸Hf (^178m2Hf, 574.215 keV, 31 y) and ¹⁷⁹Hf (^179m2Hf, 362.55 keV, 25.05 d) through reactions induced by 14.8 ± 0.2 MeV neutrons on natural hafnium were measured for the first time. The monoenergetic neutron beam was produced via the ³H(d, n)⁴He reaction on ZF-300-II Intense Neutron Generator at Lanzhou University. Induced gamma activities were measured by a gamma-ray spectrometer with high-purity germanium (HPGe) detector. Measurements were corrected for gamma-ray attenuations, random coincidence (pile-up), dead time and fluctuation of neutron flux. The neutron fluence were determined by the cross section of ⁹³Nb(n, 2n)^92mNb reaction. The neutron energy in the measurement were by the cross section ratios of ⁹⁰Zr(n, 2n)^89m+gZr and ⁹³Nb(n, 2n)^92mNb reactions.     

Separation of Zr in the rubble waste generated at the Fukushima Daiichi Nuclear Power Station

Separation method of Zr using trans uranium resin (TRU resin) and tetra valent actinide resin (TEVA resin) was developed for the analysis of ⁹³Zr contained in the rubble waste. Zr, Nb, and U were quantitatively extracted on the TRU resin from 3 M HNO₃ and striped with 0.01 M HF, in addition, some part of Mo, Hg, Bi, and Th were also included in the stripping solution. The stripping solution was evaporated to eliminate HNO₃ and the residue was dissolved in 0.1 M HF. Finally, Zr was separated from Nb and Mo with the TEVA resin.