[en] Surface contamination by conducting materials, metals in particular, is one of the important causes for electric breakdown of insulators under high voltage. In order to explore the feasibility of nuclear track modification for anti-metallic contamination, polyester membranes with different thickness were bombarded by ³²S ions from the HI-13 tandem accelerator of CIAE. The tracks formed on the surface of the membranes were etched under different conditions. The insulating capability of the treated membranes was evaluated by using silver coatings to simulate the surface metallic contamination. The results indicated insulators with the surface modified by nuclear pore technique have an improved capability of anti-contamination of metals. The sample with 144 nm Ag coating is not breakdown under 1000 V. (authors)

[en] China is developing nuclear power rapidly, and it has been announced that China will take the technical route of closed fuel cycle. So it is necessary to carry out scenario analysis of nuclear fuel cycle to give information on uranium demands, development scale of different process of nuclear fuel cycle. It's necessary to analyze 'once-through cycle' for comparison of the advantages between 'closed nuclear fuel cycle' and 'once-through cycle' in terms of the availability of uranium resources and environmental friendship. According to development of nuclear power in China now and the near-and medium-term development plan, given the fact that nuclear power will reach 100 GW, 200 GW and 300 GW respectively in 2050, all nuclear power plants adopt PWRs, and the once-through technical routine is adopted, the demand of accumulated uranium and separate work are calculated with simplified model. The amount of spent fuel and spent fuel storage are also analyzed. (authors)

[en] Airborne particulates of from Liangxian Town, Beijing, have been collected by using GENT SUF sampler with size fraction of PM2.5/PM10 and nuclear pore filter. Samples have been analyzed by neutron activation analysis. And about 40 elements have been determined. Data interpretation has been carried out by using a statistic software, Statgraghic Plus. Seven factors have been found and some correlation between elements were analyzed. (author)

[en] The analytical sensitivity of U measurement by delayed neutron counting method may be improved due to the Delayed Neutron Detector installed at China Advanced Research Reactor (CARR) in China Institute of Atomic Energy (CIAE) with the highest neutron flux in Asia. The position of ³He gas tubes, the size and geometry of CARR Delayed Neutron Detector (CDND), Cd foil and lead walls were optimized to obtain a sufficiently large neutron counting efficiency for the delayed neutrons induced by reactor neutrons on the ²³⁵U nuclide using MCNPX code. The ²³⁵U sample was irradiated using a 30kW Miniature Neutron Source Reactor at China Institute of Atomic Energy and counted using the CDND. The test results show a satisfactory performance with the neutron detection efficiency being about 1.3% of CDND within an error being 0.2% of MCNPX. (authors)

No abstract available

[en] polyester and polycarbonate membranes with different thickness were bombarded by the heave particle, ³²S, induced from the tandem accelerator of China Institute of Atomic Energy. Then the bombarded membranes were etched at different conditions, such as etching time, concentration of sodium hydroxide solution and temperature. The effect of etching for the porous shape, diameter size and membrane surface losing were also investigated at present work. The insulating capability of anti-metallic contamination of treated membranes were evaluated by using silver coatings. The results indicated the insulating capability of anti-metallic contamination is greatly improved. (authors)

[en] Neutron-induced prompt-γ activation analysis (PGNAA) is one of the nuclear analytical methods, which is a powerful tool for quantitive determination of H, B, etc. The applications of PGNAA are increased in recent years. In this paper, the basic principle of PGNAA was introduced briefly. The facilities of PGNAA in HWRR of China Institute of Atomic Energy as well as the efficiency calibration for a wide range gamma from 50 keV to 10 MeV were emphasized. A deep sea polymetallic nodule CRM, GSPN-3 was analyzed by using PGNAA, and the results are in agreement with the certified values. (authors)

[en] Polyester membranes with different thickness were bombarded by ³²S ions from the HI-13 tandem accelerator of China Institute of Atomic Energy. The bombarded membranes with different densities of tracks were etched at different conditions, such as etching time, concentration of sodium hydroxide solution and temperature. The effects of etching condition on the pore shape and pore size were also investigated. The insulating capability of anti-metallic contamination of treated membranes was evaluated by using silver coatings. The results indicate that the insulating capability of nuclear pore- modified materials in anti-metallic contamination is greatly improved. (authors)

[en] In this paper,computational methods are used to optimize the design of a prompt-gamma neutron activation analysis (PGNAA) system on China Advanced Research Reactor (CARR). Approaches are adopted for obtaining accurate neutron beam parameter and saving the computing time. For the radiation shielding design, the optimizing factors include the cost, weight, volume, machining convenience and background radiation at the detector position. Low background spectrum and high sensitivity are expected. The simulation results, and experiences from international PGNAA community, were used in the design of the CARR PGNAA system. (authors)

[en] High energy heavy ions generate potential tracks on the face of insulated material, and a porous surface with gradient refractive index can be formed by etching the ion tracks. Here, a simple geometrical model for simulating the porous surface is proposed which can calculate the refractive index with the effective medium theories. (authors)