Investigation of Anode Striation in 34＂ VGA Shadow Mask PDP

A macro-cell was used to study the phenomenon of anode striation on a 34 VGA Shadow Mask Plasma Display Panel （SMPDP）. The breakdown process in the sustaining period of the macro-cell was taken by an Intensified Charge Coupled Device（ICCD） with narrow band filters. The mechanism of formation and evolution of the anode striation on SMPDP were investigated. The influence of the width of the electrode, the sustaining voltage, sustaining frequency and the voltage of the shadow mask on the anode striation was also studied. The results showed that the width of the electrodes, the sustaining voltage and frequency had a strong influence on the anode striation. The voltage of the shadow mask, however, hardly affected the anode striation, the firing voltage or the sustaining voltage.     

CEFR非对称运行工况的研究

为研究中国实验快堆（CEFR）非对称运行工况,通过快堆系统安全分析程序OASIS及堆芯子通道分析程序COBRA对CEFR单环路运行时堆内的温度以及流量进行了计算。结果表明,CEFR在单环路运行,完好环路一、二次钠泵转速为500 r/min,且事故环路一次钠泵逆止阀开启时,堆芯最多开启在14%的功率水平,以确保反应堆处于安全状态。     

Numerical Study of High Heat Flux Performances of Flat-Tile Divertor Mock-ups with Hypervapotron Cooling Concept

The hypervapotron (HV), as an enhanced heat transfer technique, will be used for ITER divertor components in the dome region as well as the enhanced heat flux first wall panels. W-Cu brazing technology has been developed at SWIP (Southwestern Institute of Physics), and one W/CuCrZr/316LN component of 450 mm×52 mm×166 mm with HV cooling channels will be fabricated for high heat flux (HHF) tests. Before that a relevant analysis was carried out to optimize the structure of divertor component elements. ANSYS-CFX was used in CFD analysis and ABAQUS was adopted for thermal–mechanical calculations. Commercial code FE-SAFE was adopted to compute the fatigue life of the component. The tile size, thickness of tungsten tiles and the slit width among tungsten tiles were optimized and its HHF performances under International Thermonuclear Experimental Reactor (ITER) loading conditions were simulated. One brand new tokamak HL-2M with advanced divertor con?guration is under construction in SWIP, where ITER-like ?at-tile divertor components are adopted. This optimized design is expected to supply valuable data for HL-2M tokamak.     

钛合金在高温高压过热蒸汽中的腐蚀机理研究

研究了T225NG和T42NG合金在高温、高压、过热蒸汽中长时间的氧化腐蚀规律。对试样表面氧化膜元素、相组成及表面形貌进行了测试与分析，给出了两种合金的腐蚀动力学模型．并对两种合金的腐蚀机理进行了初步分析。结果表明，两种钛合金中主元素Ti优先产生氧化腐蚀，合金元素Al和Fe及N、H、C等杂质元素对腐蚀起到促进作用，并在合金表面呈现出典型的结晶学特征。两种钛合金的腐蚀动力学规律均服从Wagner理论中的近抛物线规律。     

模拟高盐溶液中硫酸钛水解对Sr的去除研究

研究了硫酸钛在模拟高盐溶液中的水解反应对Sr²⁺的吸附能力并对其水解产物进行了分析。首先,通过电感耦合等离子体质谱（ICP-MS）对硫酸钛水解过程中对Sr²⁺的吸附能力进行了研究;其次,通过扫描电子显微镜（SEM）和X射线衍射（XRD）对硫酸钛水解产物的形貌及结构进行了表征;最后,对该工艺进行了放射性工程热试验验证,验证试验以100 L/h的废液处理规模,连续运行105 h。研究结果表明,随着溶液pH值的升高,硫酸钛水解对Sr²⁺的吸附能力逐渐增强。当pH=13时,吸附能力达到最大值,此时对Sr²⁺的吸附率达99.4%,对Sr²⁺的吸附量为1.67 mmol/g。另外,研究还证明,该吸附过程是短时间内完成的,反应时间对吸附率基本无影响。放射性工程热试验验证了工艺的可行性,试验中⁹⁰Sr的去污因子（DF）达215。     

Experimental and Analytical Study on Enhancement of Simultaneous Radiative and Convective Heat Transfer by Porous Bodies with High Porosity

An experimental and analytical study has been performed to clarify the effect of porous bodies on heat transfer at high temperatures. It is found that placing porous bodies in a duct, prominent heat transfer enhancement is attained due to both the absorption of intensive thermal radiation from the heating wall and the promotion of convective heat transfer by porous bodies and that radiation effect is notably appeared in the porous bodies with high permeability. On the other hand, analytical model developed here is successfully applied to predict the effect of radiation on heat transfer and the excellent agreements between the theory and the experiment are obtained.     

An Analytical Study of Nonlinear Reactor Dynamics Based on Bifurcation Theory with Reference to BWR Power Oscillation

A nonlinear reactor dynamics model of reduced order is derived and an analytical study on BWR power oscillation is made using this model. It provides some essential features which are not given by numerical studies, such as the explicit expressions of the linear stability condition and the weak stability condition which is related to the periodic motion. In addition, the relation between the reactivity feedback and these conditions is obtained. The application of the analytical results to the qualitative analysis of BWR dynamics is easy and quick in comparison with numerical approaches.     

高钚含量样品中α能谱法分析~(237)Np的可行性研究

通过对244 Cm的α实验谱进行拟合得到单能峰的峰形参数,采用随机抽样技术表征谱计数的统计涨落,建立了一种模拟半导体α能谱的方法。利用该方法模拟238Pu和243Am的α能谱,与实验谱基本吻合,证明了方法的可靠性。在此基础上,研究了239Pu对237Np的α能峰的影响,结果表明,当239Pu与237Np的活度比A(239Pu)/A(237Np)≤10时,通过解谱得到的A(239Pu)/A(237Np)与设定值的相对偏差≤2.0%。对于A(239Pu)/A(237Np)约为3 000的样品,如果对钚的去污系数达到300以上,则可由α能谱法测量样品中的237 Np。     

An Experimental Study of Thermal-hydraulic Phenomena in the Downcomer with a Direct Vessel Injection System of APR1400 during the LBLOCA Reflood Phase

The direct vessel injection (DVI) mode is adopted as a safety injection system in the place of a conventional cold leg injection (CLI) mode in the Advanced Power Reactor 1400MW (APR1400). It is expected that “sweep-out” and “direct ECC (Emergency Core Cooling) water bypass” are two most important bypass mechanisms of ECC water injected through the DVI lines during the LBLOCA reflood phase. Using the test facility of plane-channel type scaled down to 1/7 ratio of the prototype reactor (APR1400), we carry out the following tests for the investigation of the two mechanisms: water film spreading test, sweep-out test, and direct ECC water bypass test. From the water film spreading test, it was found that the curvature effect is negligible and the present modified linear scaling law is more appropriate than the linear scaling law. In the sweep-out test, the continuous onset is used to analyze the water height in the downcomer and the amount of ECC water bypass by sweep-out is compared with the previous correlations. The direct ECC water bypass test is performed in order to understand the ECC water film behavior in the downcomer.     

高浓UO22+存在下20%TBP-20%TRPO/煤油混合体系萃取UO2+2,Pu4+,Am3+,Eu3+和TcO-4的研究

研究了不同酸度下20%TBP(磷酸三丁酯)-20%TRPO(混合三烷基氧膦)/煤油混合体系对UO22+的萃取,探讨了常量钠盐的存在对该混合体系萃取UO22+的影响,测定了高浓UO22+存在下混合体系对Pu4+, Am3+,Eu3+和TcO-4的萃取分配比,并与无UO22+条件下的分配比进行了比较.