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BACKGROUND The traceability study of uranium ore concentrates plays an important role in nuclear forensics. By measuring the abundance ratios of lead and stontium isotopes, the results can provide some geographical indication information for traceability. OBJECTIVES To achieve the separation of large amounts of uranium from trace lead and strontium and to establish a set of methods for separating lead and strontium from uranium ore concentrate, while providing technical support for the establishment of a lead and strontium isotopes database in uranium ore concentrate. METHODS Based on Eichrom Sr resin's adsorption properties for lead and strontium, the main factors (acidity, current velocity and volume) affecting the recovery of lead and strontium were optimized by orthogonal testing. The best washing conditions have been determined. The combination of UTEVA resin and Eichrom Sr resin can effectively reduce uranium content in lead and strontium eluent and thus reduce the matrix effect. RESULTS The results show that the recovery of lead and strontium is more than 90% and the uranium content in lead and strontium eluent is less than 500ng, an improvement on the reported value of 48.8μg. CONCLUSIONS The actual uranium ore concentrate samples were measured by this method. The results show that the lead and strontium isotope abundance ratios can be used as the geographical traceability criteria for uranium ore concentrates, providing a technique for the future establishment of lead and strontium isotope databases for uranium ore concentrates.

Determination of impurity elements in uranium products is very valuable in nuclear forensics tracing and quality control of fuel cartridges. The accuracy of determination is controlled by procedure blank and the recovery of impurity elements. In this study, a method for rapid separation of uranium from impurity elements by UTEVA resin and determination of impurity elements by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) was developed. Results show that UTEVA resin has a strong absorption of uranium. When the sample weight is 16.43 mg, decontamination factor for uranium in the whole procedure is greater than 3×105, the recoveries of nine impurity elements range from 95.1% to 105.1%. The contents of impurity elements in national standard material, GBW04205, are consistent with the reference values within the uncertainty (k=2). The proposed method has good decontamination ability for uranium and is suitable for analyzing impurity elements in low weight uranium samples. This method provides technical support for nuclear forensics tracing and quality control of fuel cartridges.

Everyone is equal before the law. It is the basic principle and a symbol of the country under the rule of law. But the punishment to minor offenders in China is very different from that to the adults, with a special decision made for leniency, mitigation and exemption from sentence in view of the physiological characteristics of minors and fundamental and long-term interests of the society. Such a special provision to special groups does not run counter to the principle that everyone is equal before the law but should be executed concretely and efficiently. To implement the legislative spirit that the minor offenders should be punished leniently, the special state organs and social functional departments should insist on focusing on the policy of prevention first and establish an effective community working mechanism for juvenile delinquency to which education should play a core role in prevention. The criterion of imposing penalty and conviction to minors' out-of-rule behavior should be accurate. [ABSTRACT FROM AUTHOR]