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Polyvinyl alcohol (PVA), a high molecular polymer, has good barrier property, acid or alkali resistance and degradability, which could be used as personal radiation protective equipment and pollution control articles in the nuclear industry, resulting in degradable radioactive technical wastes after use. The degradation treatment process of PVA degradable technology waste can realize validity separation of radionuclides and reduce the output of radioactive solid waste. In this study, MnxOy/γ-Al2O3, CuxOy/γ-Al2O3, FexOy/γ-Al2O3 and FexCuyMnzOw/γ-Al2O3 nanoparticles were prepared by the impregnation-calcination method, which were used as catalysts for the oxidative degradation of ultra-high concentration PVA organic waste solution, and the effects of initial pH of polyvinyl alcohol (PVA) solution, hydrogen peroxide (H2O2) dosing, catalyst dosing and initial concentration of PVA solution on the degradation of PVA were analyzed. The results showed that the best overall degradability was achieved by using FexCuyMnzOw/γ-Al2O3 nanoparticles as catalysts with the initial reaction concentration of PVA at 1%, the initial pH of the solution at 3, the reaction temperature at 60 °C, the catalyst dosage at 0.5 g/L and the H2O2 dosage at 60 mL/L. At this time, the concentration decrease rate of PVA could reach more than 95 %, the viscosity average molecular weight of degradation products reached 1395, the molecular weight decrease rate reached 99 %, and the degradation products mainly included butanone, benzaldehyde, hexanal, acetic acid and other unsaturated small molecules. In addition, the mechanism of hydroxyl radical generation by nanoparticles catalyzing hydrogen peroxide was discussed, and the reaction pathway of oxidative degradation of PVA macromolecules by hydroxyl radicals was proposed, which provided a reference for volume reduction treatment of PVA degradable waste in nuclear industry.

Depleted zinc injection into the reactor coolant system (RCS) of pressurized water reactors (PWRs) has demonstrated benefits for significantly reducing radiation fields. Liquid chromatographic separation of zinc isotopes to produce depleted zinc was attempted. A novel chelating resin PS-g-GMA@IDA containing iminodiacetic acid (IDA resins) for separation of Zn2+ and zinc isotope was synthesized by γ-ray induced co-irradiation grafting of glycidyl methacrylate (GMA) onto polystyrene (PS) spherical resin, followed by ring-opening processes with iminodiacetic acid. The obtained chelating resin PS-g-GMA@IDA before and after adsorption of Zn2+ were characterized by FT-IR spectra. This showed that the adsorption of Zn2+ by chelating resin involved two processes. Firstly, zinc ions displaced the hydrogen of the carboxyl group on chelating resin, then Zn2+ chelated with oxygen atom to form a ring structure through the coordination bonds. Adsorption abilities of PS-g-GMA@IDA were evaluated by batch adsorption experiments. The effect of pH and initial concentration on adsorption capacity of PS-g-GMA@IDA were investigated. The highest adsorption capacity 130.1 mg/g for (CH3COO)2Zn was obtained at pH = 6 within 24h when C0 were 200 ppm. EDTA-(NH4)2 was selected as eluent because of its high desorption rate of zinc. A dynamic column adsorption test was carried out at 25 °C using a 1 m column packed with PS-g-GMA@IDA, and the breakthrough occurred at about 500 ml efflunent volume. Column capacity calculated from the breakthrough curve was 56.83 mg/g. Na type PS-g-GMA@IDA was utilized to carry out column chromatographic experiment for zinc isotope separation. Under the conditions of 278±1 K, migration distance 1+9 m and EDTA-(NH4)2 as eluent, the the maximum enrichment value of 66Zn/64Zn and 68Zn/64Zn in the effluent is 1.0268 and 1.0451 respectively.

Supercharged boilers are widely used as the core equipment of ship steam-power plants. A 1:1 model is built considering the connection details of tube-tubesheet joints. Furthermore, numerical simulation of stress field and fatigue life based on the DBA method is conducted. The results show that the maximum equivalent stress amplitude of 253.81 MPa appears on the tube-tubesheet joint of the tube plant radiation area. The total stress amplitude is dominated by the thermal stress range. The last calculated permissible number of cycles based on the fourth strength theory is 161,744 times, which is 15.7% higher than the result calculated by the third strength theory.