[en] ⁹⁹Tc^m is the most frequently used for clinical diagnosis in nuclear medicine, accounting for some 70% of all radionuclides used for diagnosis. ⁹⁹Tc^m is mainly produced from decay of its parent nuclide ⁹⁹Mo via the ⁹⁹Mo-⁹⁹Tc^m generators. China has developed technology for medical ⁹⁹Mo and ⁹⁹Mo-⁹⁹Tc^m generators since 1960s, and has made remarkable achievements. In present work, the development of medical ⁹⁹Mo and ⁹⁹Mo-⁹⁹Tc^m generators in China is briefly reviewed, and involved problems for production of medical ⁹⁹Mo and ⁹⁹Mo-⁹⁹Tc^m generators are discussed. Furthermore, some suggestions on the future development of ⁹⁹Mo and ⁹⁹Mo-⁹⁹Tc^m generators are provided, which is expected to promote the further development of radioisotopes technology in China. (authors)

[en] ^99mTc, as the decay daughter of ⁹⁹Mo, is the most frequently used radionuclide in nuclear medicine. The usage of ⁹⁹Mo is not less than 70% of that of the all radioisotopes. The methods for ⁹⁹Mo production by nuclear reactors, accelerators and neutron generators were studied. Here, based on the investigated literatures, methods for ⁹⁹Mo production had been analyzed with an emphasis on ⁹⁹Mo production extracted from ²³⁵U fission products with high enriched uranium (HEU) or low enriched uranium (LEU) target. Due to the recently rapid development of methods for ⁹⁹Mo production by accelerators and neutron generators, the achieved progresses were reviewed in this respect. In the present paper, some advices were also given for further exploration. (authors)

[en] Radioisotope strontium-90 is a pure beta decay nuclide with a decay energy of 0.546 MeV, a half-life of 28.79 years and a specific power of 0.536 w/g. ⁹⁰Sr can be used as a beta radiation source and a heat source in radioisotopes thermoelectric generators, which has important applications to the industry, the agriculture and the medicine, ect. ⁹⁰Sr is a product of Uranium-235 fission, and the main way to obtain strontium-90 is extracting ⁹⁰Sr from high level liquid waste generated from the spent fuel reprocessing. Some methods, including precipitation, ion exchange, solvent extraction and chromatography, have been used for ⁹⁰Sr extraction, and several procedures also have been developed. In present work, the progress on the extraction of ⁹⁰Sr using solvent extraction methods has been reviewed to provide reference for further work. (authors)

[en] Radioisotopes play an important role in industry, agriculture, medicine and scientific research. Presently, a brief overview on development of radioisotope preparation technology in the past six decades at China Institute of Atomic Energy (CIAE) was performed with an emphasis on the development of some reactor-produced radioactive isotopes (⁹⁹Mo, ¹²⁵I, ¹³¹I, ¹⁷⁷Lu), cyclotron-produced isotopes (¹⁸F, ⁶⁴Cu, ⁸⁹Zr, ¹²³I) and three kinds of generators (⁹⁹Mo-⁹⁹Tc^m, ⁶⁸Ge-⁶⁸Ga and ¹⁸⁸W-¹⁸⁸Re). Meanwhile, prospects for radioisotope preparation technology are provided, which will be expected to boost its development at CIAE. (authors)

[en] Radioisotopes play an important role in the development of national economy and health care. In the present paper, a brief overview on development of radioisotopes preparation technology in the past three decades in China was performed. The development of preparation technology for some important radioactive isotopes, such as ¹⁴C, ⁶⁰Co, ⁹⁹Mo, ^123/125/131I, ¹⁷⁷Lu was described. Based on the analysis of the existing problems on the development of radioisotopes preparation technology, solutions to this issue are pointed out, which will be expected to boost the development of radioisotope preparation technology in China and finally serve the domestic radioisotope production in future. (authors)

[en] To explore the adsorption properties of Mo (VI) by AG1-X8 resin, the effects of adsorption medium, adsorption time, and temperature on the adsorption of Mo (VI) as well as its adsorption and desorption on AG1-X8 resin have been investigated. The results showed that the adsorption rate of Mo (VI) on AG1-X8 resin was higher than 97% in the range of 0 ∼ 5 mol/L NH₄OH but decreased with increasing the concentration of HN0₃. The adsorption of molybdenum by AG1-X8 resin achieved equilibrium within 1 min and followed Langmuir isotherm model in 1 mol/L NH₄OH, which process was spontaneous and endothermic in nature. Mo (VI) could not breakthrough the column during as NH₄OH and water passed through the AG1-X8 resin column, and 98.5% of Mo (d) could be eluted by 3 mol/L HNO₃. (authors)

[en] The loop system for iodine-125 production by China Advanced Research Reactor (CARR) was a set of device which was fully enclosed and long pipe system that made by stainless steel. The system must be strict installation and debugging before installation in the reactor, and it need to leak detection as well to ensure design requirements. According to the requirements of the place of CARR, the designing and debugging simulation system was primarily focused, mainly including the system's installation, vacuum debugging and Xenon gas recovery test. The methods of subsection debugging for long pipeline and guiding gas test with the pipe system were carried out. After the installation and commissioning of the system, recovery simulation experiment of natural abundance of xenon was also carried out. The results showed that the I-125 simulation loop was a slender and multi bending pipeline. The system had good seal ability and the measured value less than 10^-6 Pa · m³/s of leak detection by helium mass-spectrometer leak detector. It took 120 seconds to recover the guiding natural Xenon, which could meet the design requirements. The system scheme was feasible and provided the basis for further iodine-125 production of loop circuit method by reactor. (authors)

[en] The information of primary knock-on atom of material under neutron radiation in nuclear reactors is the inputs for multi-scale material computational simulations. Two different computational methods for primary knock-on atom (PKA) simulation under neutron radiation, including scattering matrix transformation and Monte Carlo simulation, were investigated in this paper. The PKAs of Zr, Fe, W and SiC under the neutron radiation in pressurized water reactor (PWR) were simulated using these two methods. The energy spectrums of PKAs were attained and compared, which shows the good agreements between these two methods. Moreover, the Monte Carlo simulation method has advantages for considering the effects such as the thermal motion of target nuclides and the chemical bonds between nuclides. The research in this paper provides foundations of the follow-up molecular dynamics and multi-scale material simulations. (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] ⁹⁹mTc is the daughter nuclide of Molybdenum-99, which is widely used in clinical nuclear medicine. ⁹⁹Mo is mainly produced by fission of high enriched Uranium (HEU). To reduce nuclear-proliferation concerns, the international communities move to non-HEU-based production. It is necessary to develop the irradiation and dissolution processes of LEU metal foil target instead of HEU. To produce the same amount of ⁹⁹Mo, LEU target will contain 5 ∼ 6 times of uranium compared to HEU target. The increase of Uranium content makes it more difficult to prepare and dissolve targets. This paper aimed to design a set of dissolver for nitric acid dissolution of low enriched Uranium metal foil target. Dissolution experiments of LEU foils in different concentration of nitric acid, different temperature and different pressure were also carried out. The results showed that LEU metal foil could be dissolved in the nitric acid using developed dissolver. The preliminary investigations paved the way for irradiate uranium foils dissolution experiments and determined the dissolution conditions of uranium foil target for fission molybdenum production. (authors)