Advanced Materials Research Vols. 608-609

Abstract: The optimization database of radiation protection was designed on nuclear facilities maintenance with SQL Server 2008 in this paper. The database includes four modules, namely system login module, statistical data module, daily module and optimization module. Twenty-three data tables were designed, which could store a mass of data in orderly. The optimization database of radiation protection on nuclear facilities maintenance could store the original monitoring data such as plant radiation levels measurement figure on nuclear facilities for maintenance and maintenance daily. This database also combines with the actual demand in the engineering project to statistics and analysis the data.

Abstract: In this paper, the numerical analysis code of particle-grid hybrid method is developed by parallel computational technology. Particle-grid hybrid method is a new method for two-phase flow problem analysis. When this method was used to study the two-phase problem in nuclear power system the calculation time was very long. Hence, the MPI (Message Passing Interface) library is chosen as the parallel environment to parallel the original serial code. The grid and particle calculation parts are paralleled, separately. Jacobi point iteration method and ADI (alternating direction implicit) combined with divide and flow line programming techniques for grid calculation are discussed. Then several cases are set for testing the parallel efficiency of different pressure correction equation solution methods. This method has been proved to be accurate and reliable compared with the results of original serial code; it can shorten the calculating time to a certain degree. And this method provides valuable references and guidelines for further improvement of hybrid method and expansion of its application fields.

Abstract: This study consists of two steps. The first step is the development of a TRACE (TRAC/RELAP Advanced Computational Engine)/PARCS(Purdue Advanced Reactor Core Simulator) model of Lungmen nuclear power plant (NPP) which includes the vessel, reactor internal pumps (RIPs), main steam lines, and important control systems (such as the feedwater control system, steam bypass & pressure control system, and recirculation flow control system), etc.. Key parameters were identified to refine the TRACE/PARCS model further in the frame of a steady state analysis. The second step is the performance of Lungmen NPP TRACE/PARCS model transient analyses. The MSIV closure direct scram (MSIVCD, MSIV = Main Steamline Isolation Valve) transient data of Final Safety Analysis Report (FSAR) is used to verify the Lungmen NPP TRACE/PARCS model. The trends of TRACE/PARCS analysis results are consistent with the FSAR data. It indicates that there is a respectable accuracy in the Lungmen NPP TRACE/PARCS model.

Abstract: This paper describes the characteristic and special considerations of human reliability analysis (HRA) in level 2 Probabilisitic Reliability Analysis (PSA), and demonstrates in level 2 PSA how to use SPAR-H method which is so-called an advanced second-generation HRA method and is being widely used in PSA for Chinese NPPs.

Abstract: A series of anion exchange membranes based on poly(arylene ether sulfone)s (PAES) have been prepared through condensation polymerization, chloromethylation and quaternization. The membrane using N, N, N’,N’-tetramethylhexyldiamine both as the quaternization and crosslinking reagent had self-crosslinking structure, and their properties have been compared with those using trimethylamie as the quaternization reagent, including ion exchange capacity, solubility, water uptake, dimensional change, hydrolytic stability and ion conductivity. The self-crosslinking membranes showed improvement in durability towards common organic solvents, dimensional stability and ion conductivity.

Abstract: Polymers based on sulfonated multiblock copoly(arylene ether sulfone)s were prepared successfully by the reaction between a phenoxide-end-capped hydrophilic oligomer and a fluoride-end-capped hydrophobic oligomer. They were subsequently used as the starting material to prepare crosslinking membranes (cbSPAES) using P₂O₅ as the crosslinking reagent during the membrane casting procedure. The fundamental properties of the resulting crosslinked multiblock membranes, such as water uptake, size change, proton conductivity and hydrolytic stability were investigated in details.

Abstract: In order to increase the corrosion resistant and reduce the interfacial contact resistance of the stainless steel, the duplex treatment technology of electroplating Cr and plasma-assisted nitriding process for AISI 304SS is exploited. X-ray diffraction (XRD), scanning electron microscopy (SEM) and the electrochemical tests such as potentiodynamic and potentiostatic polarization in the simulation PEMFC environments are measured. XRD showed that the surface layer of the 540 ° C and 550 ° C were Cr and Cr2N; the 580 °C was the CrN and Cr₂N. The nitride sample of the 550 °C could see the closure process of the mesh crack. Compared with the simulated PEMFC anode environment, higher corrosion resistance was showed in the simulated PEMFC cathode environment. The current density of the 540°C, 550°C and 580°C samples were negative at the operating potential -0.1V, which would provide cathodic protection to the metallic bipolar plates. In the simulated cathode environment, the current densities of the three samples were quickly stabilized, the surface quickly formed a stable passive film.

Abstract: Using impregnation-chemical reduction method, we prepared Pt/C and Pt-Ag/C nano-catalysts. Both of them are with the same platinum content. The composition of the two catalysts was analyzed by XRD technique. The electrochemical performance was studied by cyclic voltammetry and current-time curve. The results show that: the existence of Ag in the Pt-Ag/C catalyst makes Pt crystallinity decreased; compared with Pt/C, Pt-Ag/C has a higher reductive peak current. In addition, both catalysts show the excellent catalytic stability.

Abstract: The two-phase united anaerobic fermentation has been paid more and more attention in recent years. But how to increase the biogas production yield and the degradation rate of organic matter needs more research. The batch anaerobic fermentation studies demonstrated the feasibility of H2 and CH4 generation utilizing kitchen wastewater as substrate, and the vaccination rate, dilution rate, substrate concentration were optimized. The conclusion showed that dilution rate is the most important factor, following by kitchen wastewater concentration and inoculum volume. The most excellent program of the organic load, the inoculation volume and the dilution volume are 150 +300 ml, 135 ml, 225 ml, respectively. Under these conditions the hydrogen and methane production rate were the highest of 4.15 ml/ml，2.55 ml/ml (calculated as the wastewater volume), respectively. The acid-forming pathways of kitchen wastewater was typical butyric- propionic acid mixed fermentation type. The appropriate dilution could decrease the concentration of the total acids and increase the biogas production yield.

Abstract: Seeking for reducing the cost of hydrogen energy fuel cells, one of the key points is reduce Pt loading in Pt/C catalytic electrode. Meanwhile, there is no negative impact about efficiency of electrode reactions. We manufactured PtCuCeO_x catalyst for fuel cell by Ion Beam Sputtering (IBS). In this paper, the electrodes were processed by different annealing temperature and acid treatment temperature for post-processing. An appropriate amount of Cu dopant can reduce the Pt loading, and the catalytic performance won't reduce. Doping CeO_x refined PtCu alloy crystal particle, active surface area of the electrode was improved. It had shown that Pt atoms accounted for 72%, Pt load 0.0618mg/cm2 by SEM + EDS and ICP-AES data. Performance of electrochemistry was increased by 40.5%. It showed the characteristics had low Pt loading with high performance of hydrogen evolution.