Development of systems reliability analysis code SECOM-2 for seismic PSA

An integrated code system SECOM-2, developed at the Japan Atomic Energy Research Institute (JAERI), has the following functions for systems reliability analysis in seismic probabilistic safety assessments (PSAs): (1) calculation of component failure probability, (2) extraction of minimal cut sets (MCSs) from a given fault tree (FT), (3) calculation of frequencies of accident sequences and core damage, (4) importance analysis with several measures with consideration of unique parameters of seismic PSAs, (5) sensitivity analysis, and (6) uncertainty analysis. This paper summarizes the special features of SECOM-2 to perform the analyses mentioned above. At JAERI, using an integrated FT which represents seismically induced core damage due to all initiating events as a system model to calculate core damage frequency of a nuclear power plant, SECOM-2 can calculate conditional point estimate probabilities of system failures, losses of safety functions, and core damage as a function of earthquake motions. The point estimate is computed by a method which gives an exact numerical solution using the Boolean arithmetic model method. As for consideration of correlation of component failure, which has been an important issue in seismic PSAs, a new technique based on direct FT quantification by a Monte Carlo simulation is being added to SECOM-2. Adding this technique, the core damage frequency can be calculated not only with the upper bound approximation based on MCSs but also with a near exact solution taking into account the correlation among all components. This paper also presents the preliminary results of a seismic PSA of a generic BWR plant in Japan performed at JAERI to demonstrate the functions of the SECOM-2 code.     

水平下向分层充填采矿法开采缓倾斜矿体的地压应力分析

应用岩石力学理论 ,分析缓倾斜矿体用水平下向分层充填采矿法开采地压应力 ,及时采取措施 ,提高采矿作业的安全性 ,同时也取得良好的经济效益。     

The separation of fission-product rare elements toward bridging the nuclear and soft energy systems

Based on the present state of the art of the separation technology, recycling of fission-product rare elements (FRE) in the FBR spent fuel is discussed. The rad.-waste fractionation is in accordance with the present society's trend toward zero-emission, and the mean of salt-free method utilizing electrochemistry agrees with the principles of the newly established green chemistry. A catalytic electrolytic extraction method is proposed to separate the target, radioactive but potentially strategic elements, Pd, Ru, Rh, Re (Tc), Te and Se dissolved in the HLLW. It avoids secondary waste arising. This method is particularly feasible for the separation of Pd where cyclic reaction of metal cations such as Pd(II) or Fe(II), acting as promoters or mediators and already contained in HLLW, accelerates the electrochemical deposition of Ru, Rh and Re. Elemental separation not only offers alternative material resources to meet expanding demands for catalysts in Fuel Cell/Soft Energy system but is also the first step for transmutation or other selective strategies for waste management of long-lived fission products (LLFP).     

对关闭破产矿山工作考察后的思考

本文通过介绍笔者随江西铜业公司组织的考察组赴本省、云南考察中了解的情况 ,对江西铜业公司内部矿山目前进行关闭破产工作谈些个人看法     

纳米氧化锌制备过程成核与生长控制

均相沉淀法制备纳米氧化锌的关键是成核与生长控制。过饱和度越大 ,成核数量越多 ,则生成的晶粒越小。成核数量与反应物浓度即Zn2 + 和OH-的浓度有关。采用尿素为沉淀剂 ,添加有机物羧甲基纤维素作分散剂以控制微小晶粒间的叠合生长 ,在温度 (130℃ )和反应时间 (2h～ 5h)下热压处理 ,制备了粒径较小、粒度分布均匀的纳米氧化锌     

Observing the Stimulated Raman Gain Spectra of Solutions Using an Infrared Pump Pulse with Narrow Linewidth and a Low-Noise CW Probe Laser

Stimulated Raman gain (SRG) spectroscopy using infrared pump pulses with narrow linewidth and a low-noise cw probe infrared laser was proposed. High-resolution Raman spectra of solutions were obtained. The SRG spectra of crystal GaP, benzene, and toluene were measured to confirm the spectral resolution and sensitivity over the terahertz (THz) region. We discuss the polarization dependence of the spectral measurement of carbon tetrachloride. Our system can detect organic molecules in aqueous solutions.     

Correlation between the hot plate ignition test and other laboratory-scale flammability tests on rubber conveyor belts with fabric skeletons

The hot plate ignition test was conducted on ten different conveyor rubber belts with fabric skeletons. In this test, a 25 × 25 mm² belt sample was placed on a stainless steel plate in an electric furnace and heated. The ‘ignition temperature’ was determined on each sample in almost the same way as proposed in Canada. The test results were compared with those from other laboratory-scale flammability tests (i.e. the small-scale flame tests, the Oxygen Index test and the laboratory-scale gallery test). The calculated results of both sample and rank correlation coefficients imply that the ‘10 signition temperature’ in this hot plate ignition test has a correlation with the results from both the Oxygen Index test and the laboratory-scale gallery test, but that it has very little or no correlation with those from the small-scale flame tests. On the other hand, it is found that the ‘60 s ignition temperature’ in this test has a far better correlation both with the results from the small-scale flame tests and with the time to ignition in the laboratory-scale gallery test than the ‘10 s ignition temperature’.     

Novel Route to Propylene Carbonate: Selective Synthesis from Propylene Glycol and Carbon Dioxide

High surface area zirconium phosphate in an amorphous phase exhibits high activities for water-related reactions such as hydrolysis of ethyl acetate and esterification of acetic acid with ethanol. The zirconium phosphate is insoluble during the reaction, is recoverable by simple filtration, and can be reused at least five times without any treatment.     

电动机冷却风机变频系统的改造和效果

本文简述了我厂主电机冷却风机变频系统 ,以及交流异步电动机的变频调速原理 ,介绍了变频器的工作原理、特点 ,说明了新旧控制系统的优缺点和节能效果。