[en] In this article, the 1, 4, 7, 10-tetraazacyclotetradecane-1, 4, 7, 10-tetra (4-nitrobenzyl) (L) has been synthesized successfully. The paper studies the extraction properties for thorium at different pH, different concentrations of salting agents (sodium nitrate), different extractant concentrations and different dilution respectively. The results showed that using dichloromethane as diluent in the pH=4.63, salting-out agent concentration of 1 mol/L thorium ions have a good extraction efficiency, E%=94.90%. Finally, the structures of the chelates are studied: using the slope method and equimolar series method both obtained the formation of 1 : 2 Th-L complex, and proved the structure of the extracted complex by NMR. (authors)

[en] The results of measuring of concentrations of radon and its daughters and of observing lung cancer incidence of the mines in a cupric mine from 1962 to 1981 were summarized in this paper. The factors influencing the radon daughters concentrations in the air of this mine were discussed. The radon daughter cumulative exposure and lung cancer incidence of the miners were also analyzed

[en] In this paper, the static distribution coefficient of Fe, Co in AG1-X8 in different concentrations of hydrochloric acid medium and the elution conditions of Ni in AG1-X8 were studied. A high enrichment (98.0 percent) nickel 62 target was placed in the Monogyny Research Reactor (Carr) in China and irradiated for 90 days at a neutron flux of approximately 8 × 10¹³ n • cm^-2 • s^-1. The irradiated nickel 62 (contain nickel 63) metal slice was dissolved in 10 mol/L HCl, and the nickel 63 was separated and purified by anion exchange resin AG1-X8 to realize the separation of nickel 63 and iron 59, cobalt 58 and other impurity nuclei. The experiment results showed that the static distribution coefficient of Fe, Co in anion exchange resin AG1-X8 increases with the increase of HCl concentration. When HCl concentration increases to 9 mol/L, the distribution coefficient is 177 and 12.7 respectively. The elution volume was 15 mL and the nickel recovery rate was 99.38% with 9 mol/L HCl. The theoretical specific radioactivity of ⁶³Ni was 0.51 Ci/gNi. The radionuclidic purity of ⁶³Ni was 99.99% and decontamination factor was 1.1 × 10³. The specific radioactivity of ⁶³Ni reached to 0.55 Ci/gNi. (authors)

[en] To separate molybdenum-99 from fission products of low enriched uranium (LEU) by precipitation with α-benzoin oxime (α-BO), influences of temperature, concentration of nitrate, molar ratio of α-BO to Mo, radiation dose and uranium concentration on precipitating molybdenum with α-BO had been evaluated. Re-dissolution of MoO₂(α-BO)₂ was performed. The decontamination factors of impurity elements including strontium, zirconium, ruthenium, cesium, cerium, iodine-131 and uranium had been determined. The recovery yield of Mo for the separation procedure was calculated. It showed that, at the room temperature, with 1 mol/L of nitric acid concentration, higher than 2 of molar ratio of α-BO to Mo, when α-BO was dissolved in anhydrous ethanol or 0.4 mol/L sodium hydroxide solution, higher than 95% of Mo recovery yield could be obtained. Under the radiation dose rate of 5000 Gy/h, when the radiation dose increased, Mo recovery yield decreased instead. When the total radiation dose of α-BO was below 8.25 × 10⁵ Gy, Mo recovery yield was higher than 85%. When uranium concentration increased, Mo recovery yield decreased. MoO₂(α-BO)₂ precipitate could be dissolved in sodium hydroxide of 0.5 mol/L within 15 minutes. Effective decontamination for all major impurity elements including strontium, zirconium, ruthenium, cesium, cerium, iodine and uranium were observed. This study has paved the pay for further research for fission ⁹⁹Mo production. (authors)

[en] Removal of ¹³¹I is crucial to ensure the quality of medical fission ⁹⁹Mo. The whole radiochemical extraction process of fission ⁹⁹Mo from simulated solution had been developed by aα-benzoin oxime precipitation, followed by AG1_- × 8 anion exchange and activated charcoal chromatography for further purification. To evaluate the effectiveness of removal of radioactive iodine by the established production process for fission ⁹⁹Mo, in this work, behavior of ¹³¹I^- and ¹³¹IO₃^- in the chemical process had been studied. The decontamination effectiveness of ¹³¹I^- and ¹³¹IO₃^- had been evaluated. For ¹³¹I^-, 98.2% of iodide in the simulated solution could be precipitated by AgNO₃ as AgI sal, while 97.9% of ¹³¹I^- removal efficiency was for consequent precipitating Mo with α-benzoin oxime, and higher than 99.9% for AG1_- × 8 anion exchange chromatography, about 75% for activated charcoal chromatography. After purification by the mentioned procedure for fission ⁹⁹Mo, decontamination factor (DF) of ¹³¹I^- was 1.90 × 10⁶. and the removal efficiency of ¹³¹I^- was higher than 99.99%. For ¹³¹IO₃^-, AgNO₃ could not precipitate iodate in HNO₃ solution. However, precipitating Mo with α-benzoin oxime could take away more than 99% of ¹³¹IO₃^- in solution. Consequently, 99% of ¹³¹IO₃^- in solution was removed by AG1_- × 8 anion exchange and nearly 70% of ¹³¹IO₃^- was decontaminated by activated carbon chromatography. The final DF of ¹³¹IO₃^- was 2.52 × 10⁵ and the removal efficiency of ¹³¹I^- was more than 99.99% too. The experimental results showed the established procedure for fission ⁹⁹Mo production gave excellent decontamination effectiveness for ¹³¹I. (authors)