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The results of R&D work on nuclear batteries of the capacitor-type with a liquid electrolyte are reported. A high-porosity carbon matrix containing the radioactive isotope 90Sr is used in one of the electrodes of the new type of nuclear batteries. Ionic liquids, where the charge carriers are free ions formed on dissociation of ionic pairs of the ionic liquid on account of the kinetic energy of the β-particles of 90Sr, are used as the electrolyte. The charges are separated by a double electric layer at the boundary of an electrode and liquid electrolyte similarly to supercapacitors. [ABSTRACT FROM AUTHOR]

This work is devoted to applications of the time-resolved laser- induced luminescence spectroscopy and time-resolved laser-induced chemiluminescence spectroscopy for detection of lanthanides and actinides. The limit of detection (LOD) of some lanthanides and actinides in solutions by the time-resolved laser luminescence spectroscopy is up to 10 mole/liter. Unfortunately, Pu, Np, and some U compounds do not produce luminescence in solutions, but when excited by laser radiation, they can induce chemiluminescence. The characteristics of chemiluminescence induced by excited lanthanide and actinide complexes in solutions are considered. A key problem of chemiluminescence application for lanthanide and actinide detection in solutions is the increase of the detection selectivity. This problem can be solved by using the multistep schemes of chemiluminescence excitation. It is shown that the time-resolved luminescence laser spectroscopy and chemiluminescence laser spectroscopy can be successfully used for detection of lanthanides and actinides in solutions. [ABSTRACT FROM AUTHOR]

The disturbance of the acid-base balance in photoreduction of uranyl ion in aqueous solutions is considered. The IR spectra are examined, and the causes of their differences in cases of U(VI) photoreduction in aqueous solutions based on common and heavy water are discussed. [ABSTRACT FROM AUTHOR]

The behavior of the [16O-U-16O]2+, [16O-U-18O]2+, and [18O-U-18O]2+ isotopic species in uranyl fluoride complexes was studied in isopropanol under pulsed UV irradiation of solutions at λ = 300–400 nm. Illumination of the solutions affects the isotope composition of oxygen in uranyl owing to photoreduction and isotope exchange with the water molecules occurring in the solution. The absorption spectra of the UO2F2 solutions with different isotope compositions of oxygen were measured. The enrichment of UO2F2 in 18O only slightly affects the absorption in solution. The IR spectra show that the content of the [16O-U-18O]2+ species in solution decreases more rapidly than that of [18O-U-18O]2+. Comparison of the photoreduction rates for UO2F2 species with different isotope compositions of oxygen suggests that this effect cannot be attributed to the difference in the quantum efficiencies of photoreduction for different isotopic species. Accelerated decrease in the content of the [16O-U-18O]2+ species in solution under irradiation was attributed to the excitation exchange processes in uranyl fluoride polymers. [ABSTRACT FROM AUTHOR]

Activated structural materials of fusion reactors after the reactor decommissioning may be sent either for burial or for radiochemical reprocessing and consequent material refabrication. This paper considers an opportunity of radiochemical extraction reprocessing of activated vanadium alloy, which is a potential structural material for Russian demonstration fusion reactors (DEMO). The nitrate solutions of the alloy components were used as the aqueous phase. The solution of di-2-ethyl-hexyl-phosphoric acid (D2EHPA) in a hydrocarbon solvent was chosen as an extractant in the experiments. The extraction of alloy impurities (till the dose rate level of 12.5 µSv/h) may be attained in an extractor cascade with 50 stages. End products of the extraction reprocessing are nitrate solutions of vanadium and chromium and titanium hydroxide. The expediency of the radiochemical reprocessing of the alloy or its burial may be determined after the technical and economic comparison of these processes. [ABSTRACT FROM AUTHOR]

Chemiluminescence of luminol induced by NpO22+ complexes excited with nitrogen laser radiation was studied in 42% solutions of CsF with different pH. The absorption spectra of solutions of NpO2F4OH3- complexes and the chemiluminescence spectra of these solutions containing luminol and having different pH were recorded. [ABSTRACT FROM AUTHOR]

Thermal degradation of VP-1AP anion exchanger and its mixtures with HNO3 was studied in open vessels at 40 to 260°C. The anion exchanger ignites only after drying and heating to 220-260°C. Heating VP-1AP mixtures with 3-12 M HNO3 to 100°C is accompanied by gas evolution at a rate of 0.6 l min-1 (lsorb)-1. Removal of the aqueous phase from the mixtures at 130-170°C initiates intensive oxidation. It is accompanied by a temperature jump in the sorbent phase and by gas evolution acceleration and can be regarded as thermal explosion. Mixture preheating and irradiation reduce the thermal explosion "onset" temperatures. [ABSTRACT FROM AUTHOR]

Thermal gravimetric analysis of the samples of VP-1AP anion exchanger in sulfate and nitrate forms was carried out. In the derivatograms of the anion exchanger in the nitrate form there are one endothermic and two exothermic peaks (∼100, 160-180, and 200-220°C). Heating of dry samples of VP-1AP anion exchanger in the nitrate form at 130-230°C induces oxidative degradation of the sorbent matrix with participation of nitrate ions. In the presence of products of anion exchanger degradation and sorbed HNO3 in the anion exchanger phase, the weight loss of the samples abruptly increases at temperatures of approximately 180-190°C. The action of ionizing radiation strongly affects the heat resistance of the anion exchanger. At absorpbed dose of 5 MGy the first exothermic peak is shifted by 15-20°C; in this case, both exothermic peaks coalesce and the oxidation can be considered as single-stage process starting at 110°C. [ABSTRACT FROM AUTHOR]

Variation of physicochemical characteristics of VP-1AP anion-exchange resin in HNO3 solutions on heating and under the action of external γ-radiation up to the absorbed dose of 5 MGy was studied. It was shown that at thermal treatment of anion exchanger with increasing HNO3 concentration and temperature and under the action of ionizing radiation the total exchange capacity (TEC) and capacity with respect to strongly basic groups ( Cs b g) decrease. The swelling coefficients Ks w noticeably vary only in treatment in 12 M HNO3 solutions and reach a maximum of 1.4. In this case, the specific surface area of the sorbent decreases from 15.7 to 1.2 m2 g- 1. Under the action of ionizing radiation the specific surface area of the irradiated anion exchanger somewhat increases and reaches 18 m2 g- 1. [ABSTRACT FROM AUTHOR]

The behavior of the Pu2 2 + ion excited by radiation of a pulse nitrogen laser in aqueous solutions with a high content of CsF was studied at various pH. Chemiluminescence of luminol under the action of OH radicals arising in the solution was considered. The absorption spectra of PuO2 2+ complexes in aqueous solution with a high content of CsF are presented. [ABSTRACT FROM AUTHOR]

Data are reported on the use of extraction generator for preparing high-purity 99mTc from 99Mo, and the quality of the solution of 99mTc is studied. The radiolysis products of the extractant, methyl ethyl ketone (MEK), are examined; the major products are MEK dimers, and their content under operating conditions does not exceed 0.005%. A high degree of removal of both inorganic and organic impurities from the 99mTc eluate obtained from the extraction generator (Radium Institute) is achieved. This ensures a high quality of radiopharmaceuticals prepared from this 99mTc solution. The 99mTc solution prepared with the extraction generator surpasses in quality the similar solution prepared with the sorption generator. When a centrifugal extractor is used for separating 99Mo and 99mTc, the concentration of MEK in the solution of 99mTc does not exceed 0.04 mg ml-1. [ABSTRACT FROM AUTHOR]

Results of experiments on initiation of luminol chemiluminescence by multiquantum excitation of U(IV) in aqueous solution by dye laser radiation in the visible range are reported. [ABSTRACT FROM AUTHOR]