Search

The electrochemical behaviors of SmCl3 and SmCl3-GaCl3 on Mo cathode in LiCl-KCl molten salt were studied by cyclic voltammetry(CV), square wave voltammetry(SWV), and open circuit chronopotentiometry(OCP). The electrochemical results of SmCl3 on Mo cathode show that Sm3+ undergoes a single electron transfer reaction in the LiCl-KCl molten salt system, and can only be reduced to Sm2+. The diffusion coefficient of Sm3+ and apparent standard potential of Sm3+/Sm2+ at different temperatures were calculated. The co-deposition of SmCl3 and GaCl3 results indicate that Sm and Ga can form SmGax alloys. The phase of SmGa2 that is obtained by electrolyzing of LiCl-KCl-SmCl3-GaCl3 at -1.600 V is confirmed by XRD and SEM&EDS. The results above reveal that on the addition of GaCl3, Sm can be effectively extracted from the LiCl-KCl molten salt system.

The electrolytic separation of actinides(An) from fission products(FPs) on solid Al cathode is one of the most promising pyrochemical reprocessing processes. In this work, the electrochemical behaviour of Pu3+ on active Al solid cathode was studied through the transient electrochemical method. Based on the results of cyclic voltammetry(CV) and square wave voltammetry(SWV), Pu3+ can be reduced into alloy through a onestep threeelectrons transfer process on Al cathode, and the reaction is irreversible. The relationship between the reduction potential of the alloy formed by Pu3+ with Al and temperature is EΘ,*(Pu3+/PuAln)(vs. Cl-/Cl2)=-2.944+9.84×10-4T. Five Pu alloys(involving Pu3Al, PuAl, PuAl2, PuAl3, and PuAl4) are formed according to the results of open circuit chronopotentiometry(OCP) together with phase diagrams of Pu-Al. Furthermore, the formation Gibbs free energies of PuAl4 at different temperature are calculated.

Fast reactor spent fuel with high burnup has the characteristics of high plutonium content, high radioactivity and high heat release rate. The aqueous reprocessing based on solvent extraction principle has the problem of solvent radiolysis. It is better to adopt the dry reprocessing. Dry reprocessing based molten salt electrolysis using irradiation-resistant inorganic salts as media, through electrochemical separation and recovery of actinide, is the most promising dry reprocessing technology. In the process of molten salt electrolytic dry reprocessing, the electrorefining unit is the core link which is responsible for the actinide separation. In this paper, the research and development progress of electrorefiner in the dry reprocessing of spent fuel is investigated, and the key technologies and development trend of electrorefiner are analyzed, which provides a reference for the research and development of fast reactor spent fuel reprocessing in China.

Studying the distribution characteristics of bioaerosols and their interaction with the environment is crucial for dairy farms. The distribution of aerosols differs in dairy farming from farming of other livestock, and their sensitivity to environmental factors varies across sites. Field experiments were conducted in an intensive commercial dairy farm in Northern China to investigate the horizontal and vertical distribution of culturable bacterial bioaerosols. Concentration levels and particle size ranges were analyzed, and the impact of multiple environmental factors on culturable bacterial bioaerosols was assessed. Significant variations in culturable bacterial bioaerosol concentrations were observed across eight functional zones, ranging from 1.14 × 103 to 7.35 × 103 CFU/m3. Culturable bacterial bioaerosols exhibited consistent carrier distribution patterns across six different size ranges. Vertical analysis revealed significantly higher culturable bacterial bioaerosol concentrations at a 1 m height compared to 4 m (p < 0.05), while similar size distributions were observed at different heights of the same sampling location. The top three environmental factors influencing culturable bacterial bioaerosol concentrations were PM100 concentration, wind direction, and air temperature. This study provides insights into the distribution characteristics of culturable bacterial bioaerosols on dairy farms and their response to environmental factors. The findings serve as a reference for evaluating bioaerosol emissions and establishing daily disinfection management measures on dairy farms.

In this study, the chlorination mechanism and influencing factors of uranium oxides(mainly U3O8) were studied by using CCl4 and HCl gas as chlorination reagents respectively. The chlorination of U3O8 powder was studied with CCl4 as chlorination reagent. The mechanism and kinetic behavior of the chlorination reaction were studied by thermogravimetric analysis. The main chlorination product is UCl4. The chlorination of different types and morphologies of uranium oxide by CCl4 was also studied. The UO2 pellets are difficult to chlorinate due to their very dense structure. UO2 powder and UO3 powder are easily chlorinated by CCl4, and the chlorination products are UCl4 and UCl6 respectively. The chlorination of U3O8 powders in LiCl-KCl molten salt system was carried out using HCl gas as the chlorination reagent. The effects of reaction temperature, chlorination time, HCl gas flow rate, feeding amount of U3O8 powder, and uranium oxide types and morphologies were studied. The results show that increasing the reaction temperature, prolonging the reaction time, and increasing the HCl gas flow rate are beneficial to the improvement of the chlorination rate. The process parameters of HCl gas chlorinated U3O8 powder are recommended as follows: the chlorination reaction temperature is 500 ℃, and the flow rate of HCl gas is 0.6 L/min.