[en] The adsorption of CO on TiO₂(110) is investigated using the full-potential linearized-augmented-plane-wave method. The equilibrium structures of the clean and adsorbed TiO₂(110) surfaces are optimized through total-energy and atomic force calculations. Two geometries of CO absorption, namely, OC-Ti and CO-Ti, were considered. It is found that the former orientation is preferred. The calculated adsorption energy and redshift of the CO stretch frequency based on the local-density approximation are 0.79 eV/molecule and 23 cm-1, respectively. The gradient corrections reduce the CO-TiO₂ binding energy to 0.25 eV/molecule. CO interacts with the TiO₂(110) substrate mainly via its 5σ state. Significant charge redistribution is involved in the CO/TiO₂(110) interaction, which changes the Coulomb potential and subsequently causes large shifts in the core and valence states of the CO adsorbate

[en] The third-generation nuclear power plant is the latest nuclear power plant, whose application of passive cooling system has been strengthened. Passive natural convection cooling has been typically applied in the passive core cooling system and the passive containment cooling system of AP1000 reactors, and in the ESBWR reactors. Using fluid dynamics formulas and the RELAP5 code, a simple model of natural circulation loop of nuclear reactor has been established to estimate the RELAP5 natural convection calculation capability of light-water, helium and two-phase flow. The results show that the capability of natural convection is strengthened with the increase of the thermal center difference between hot and cold sources and the increases of temperature difference between the hot and cold working fluid. RELAP5 could perform natural convection calculation very well when the fluid is single water or two-phase water, in which, the errors between RELAP5 and analytical results are below 5%. When circulation fluid is helium, the error is larger than the forgoing two kinds of fluid. (authors)

[en] A brief outline is given on internationally unified requirements of emergency response staffing to Multi-unit events of nuclear power plant after the Fukushima nuclear accident. According to the reality of China's nuclear power plants, expanded emergency response capability for responding to Multi-unit events has been discussed, based on the typical emergency state of Multi-unit events. (authors)

[en] According to China's nuclear power plant regulations and standards, the acceptance criteria based on the NUREG-0396 report is used to the plume emergency plan zoning for EPR unit. The source terms of release categories in the Level-2 PSA of the EPR unit are selected as the referenced source terms, and the individual consequence of' each source term and the weighted average of these consequences are calculated and analyzed by using MACCS code. RC205 is selected as 'the severest accident sequences' based on the frequency truncation (10^-8 reactor-year), and the consequence is calculated and analyzed. As a result, 3 km internal zone radius, and 7 km outer zone radius meets the acceptance criteria. (authors)

[en] With reference to relevant requirements of regulations and standards for domestic and foreign nuclear power plant siting, the hydrological parameters related to environment were selected from the flood, water intake, drainage and groundwater. The advantages and disadvantages were compared respectively in terms of site security, construction investment and environmental radiation effects. In flood, the difference between NPP floor elevation and DBF level was considered. In water intake conditions, the stability of beaches, water depth conditions, water quantity, water trunk length, the average sediment concentration of water and the allocation of water resources were considered. In drainage conditions, water dispersion characteristics and the size of the receiving water body were considered. In groundwater conditions, hydro-geological unit independence and groundwater exploitation were considered. (authors)

[en] The paper analyzes the main characteristics indicators of siting during the preliminary stage of a nuclear power plant in terms of four aspects: economy, technical feasibility, reliability and environment compatibility. The characteristic indicators and grading of the Hongyanhe Nuclear Power Plant are analyzed in the following four fields, i.e. safety, environment, social-economy and emergency. The thought on characteristic indicators and grading can provide effective assistance to siting during the preliminary stage of a nuclear power plant. (authors)

[en] Real-time monitoring safety parameters are very important both in NPP operation surveillance and emergency management. Base on the analysis of regulations, emergency technical requirements and technical document of NPP obtained construction license before Jan 1st of 2009, the real-time Monitoring Safety Parameters of PWR NPPs in concerning range were sorted out. (authors)

[en] As a heat dissipation system, natural-draft cooling tower is usually used for inland nuclear power plant. The waste heat of plant is transferred to atmosphere primarily by evaporating, which will bring out the potential adverse impacts,including visible plume, shadow of plume,ground deposition of drift droplet and noise. In this paper, the environmental impact prediction model of cooling tower, based on SACTI program recommended by NRC, was used to predict impacts of current three inland nuclear power sites (Hunan, Hubei and Anhui provinces). To illustrate the compatibility of SACTI in China, the prediction results were compared with GGNS power station in U.S. (authors)

[en] In this paper, we numerically demonstrate that the negative refraction of a photonic crystal immersion lens can bend a beam by unconventionally large convergence angles over π/2 in free space. This super-convergence feature leads to constructive interference of high-spatial-frequency waves in both lateral and axial directions and forms super-resolution focal areas beyond the evanescent fields. As such, a 57% reduction in the focal area compared with the diffraction-limited case of an objective with numerical aperture of 0.95 has been numerically achieved at a normalized frequency of 0.3 in a photonic crystal immersion lens, corresponding to a lateral resolution of 0.32λ as well as an axial resolution of 0.70λ. (paper)

[en] Using the method based on the density functional theory, the geometric and electronic properties of the TiO₂ single-wall nanotubes, constructed by rolling the most stable nanosheet along the (n, 0) and (n, n) directions, have been investigated systematically. The nanotubes with size from n = 6 up to n = 20 have been modeled and studied. The strain energies of the nanotubes decrease monotonically as the radii of the nanotubes increase, regardless of the rolling direction. The band gaps of the nanotubes are increasing with the increase of the n value, approaching the value of the nanosheet. However, there is one nanotube significantly different from the others, i.e., the (6, 0) nanotube. The substantial structural change of (6, 0) nanotube causes a reduction of the band gap. Then, the isovalent sulfur (S) substitution and adsorption with the (6, 0) nanotube have been studied. Energetically, S adsorption at the inner surface is preferred. Electronically, the band gaps are further reduced by 35% for S substitution of oxygen and 22% for S adsorption, respectively, making the nanotube visible light-sensitive.