Mechanical braking system for the pulsed power supply system of ASDEX Upgrade

A few years ago, IPP reviewed the safety of the ASDEX Upgrade pulsed power supply system. Two critical sub-systems had been identified: The (electrical) braking system for the flywheel generators and the oil lubrication system for the shaft bearings. A simultaneous failure of these two systems may lead to severe damages and could have consequences for the safety of operating personnel. Therefore a second, independent braking possibility for every generator was stipulated. Especially the challenges adapting a dynamometer, originally designed for motor test benches, towards a plant safety system for generator EZ4 will be described in the paper. Further on, the paper will present the problems, implementing such a system into an existing installation, including the calculation of the required supporting structure, balancing of the extended shaft line and required water cooling and control. Finally it will report on the performance achieved during operation.     

Stained glasses under the nuclear microprobe: A window into history

Stained glass fragments from the 15th, 16th and 20th centuries, belonging to Mosteiro de Santa Maria da Vitória, Batalha (Portugal), were characterised non-destructively in a nuclear microprobe. The work aimed at finding the composition of the glasses and glass paintings and relating these with the corresponding production periods.The elemental compositions of the glass fragments were obtained by means of scanning micro-beam Particle Induced X-ray Emission (μ-PIXE) spectrometry in selected cross-sections. These were complemented by micro X-Ray fluorescence spectrometry. Characterisation of colour was performed by optical absorption spectroscopy in the UV–vis range, while the corrosion products were identified by optical microscopy and μ-FTIR (Fourier Transform Infra Red) spectroscopy in combination with the data generated by μ-PIXE.Nuclear microprobe analysis allowed unveiling the compositions and structures, in particular of glass paintings and corrosion products. While it is not surprising that Fe, Cu and Pb were the main elements identified in the grisaille paintings of all studied periods, as well as Ag and Cu found in the glasses decorated with yellow silver painting, their distribution gave important clues on the materials and techniques used to manufacture these stained glasses. Furthermore, it allowed establishing a definite relation between the compositions found and the periods of production, with the added bonus of correctly reassigning the manufacturing period of some samples.     

New approaches for investigating paintings by ion beam techniques

Up to now, among the IBA techniques, only PIXE has been used for analyzing paintings. However, quantitative PIXE analysis is sometimes difficult to interpret due to the layered structure, the presence of varnish and organic binder and, in some cases, discoloration of the pigments has been observed due to the interaction of the ion beam with the compounds.In order to improve the characterization of paintings, we propose some alternative experimental procedures. First of all, backscattering spectrometry (BS) and PIXE are simultaneously combined in order to collect complementary information such as layer thickness and organic compound quantification. The simultaneous PIXE and BS experiments also have the advantage of being able to analyze the same area in one experiment. This combination, implemented with an external beam, was directly applied on paintings and on painting cross-sections for the study of Italian Renaissance masterpieces. We have obtained valuable results not only on the pigment itself but also, for the first time, on the binder to pigment proportion which is not well documented in the ancient recipes. Moreover, in order to restrain beam damages due to the ion stopping power, we propose to analyze very thin painting cross-sections by a combination of PIXE–RBS and Scanning Transmission Ion Microscopy (STIM).     

Study of white lead paint layers by the Debrecen nuclear microprobe

The white colours of cross-section samples taken from 10 paintings and 3 different kinds of modern white lead pigments were examined by PIXE using the Debrecen nuclear microprobe. Elemental concentrations of impurities relative to Pb were determined. A comparison with EDAX on the same samples is made.     

微束X射线荧光无损分析古瓷器高铅釉的方法及应用研究

研究了微会聚透镜分析高铅样品的特征,采用基于微会聚透镜的微束X射线荧光无损定量分析了一片清代彩绘瓷彩料中的元素含量,同时扫描分析了彩料中某一特定区域的元素分布。从元素分布中可推测出清代彩绘的制作工艺是先用高铅的Mn颜料绘出图案的轮廓,然后向中间填充设计好高铅的Cu颜料,或直接用高铅的Fe混合物绘画。分析结果表明,基于微会聚透镜的微束X射线荧光分析是一种较好的高铅样品的分析手段。     

废放射源整备车的研制和应用

根据废放射源治理工艺要求,研制了一台废放射源整备车。整备车作为一个可移动的操作开放型放射性物质的设施,由更衣室和操作室两个部分组成。更衣室是操作人员出入操作室的通道,内设更衣柜、监测仪表和防护用品等物品贮存柜;操作室是放射源包装、封焊、检漏和临时存放等场所,内设手套箱、不锈钢焊接装置、检漏装置、铅屏蔽容器和带水泥屏蔽的金属桶,以及工作台等设备。近一年的应用实践表明,研制的废放射源整备车能满足废源治理和安全运输的要求。     

装卸料机试验台架改造关键技术分析

装卸料机是核电厂PMC系统关键设备,制造完成后须在试验台架上进行整机调试、模拟试验,对装卸料机的整体性能进行验证,确保其功能的可靠性.通过对装卸料机试验台架的改造设计论述,解决大型工字梁校型难点,为后续类似桥梁施工积累宝贵经验;使用科学的测量方法,解决大型结构件安装中的测量问题,并合理运用了现有测量工具;在整个改造过程...     

Sample analysis of masterpieces and archaeological materials by nuclear microprobe: Principle,possibilities, preliminary results

The physico-chemical characteristics of the pigments used in oil paintings supply valuable informations concerning the age of the work and sometimes even the geographic origin of the ores used.After a review of the working principles of the nuclear microprobe and its analytical possibilities, the first results obtained by microanalysis of paint sections with the aim of nondestructive impurity content analysis of the white lead are presented.     

Reverse painting on glass as seen by the proton beam

The combination of PIXE, RBS and PIGE proves ideal for non-destructive overall analysis of reverse paintings on glass. Simultaneous PIXE–RBS studies assist to clarify the thin-layered pigment arrangements of details painted on the reverse of the glass pane. In a second measurement, the spectra of both PIGE–PIXE taken from the pure glass front side inform on the individual glass type. This complete perception of corresponding unique objects is important and valuable regarding the knowledge of special painting techniques and the necessity of preventive conservation.     

Differential and scanning-mode external PIXE for the analysis of the painting “Ritratto Trivulzio” by Antonello da Messina

Extensive PIXE investigations have been performed at the LABEC accelerator laboratory in Florence on the painting “Ritratto Trivulzio” by Antonello da Messina, one of the great Italian masters of XV Century and a pioneer in modern oil painting.It is well known that a complete and unambiguous characterisation of materials in paintings is often difficult, owing to their complex structure. For the “Ritratto Trivulzio”, the combination of advanced variants of PIXE, such as differential and scanning-mode analysis, provided a relevant contribution to the characterisation of paint layers, in terms of composition and structure, in a totally non-invasive and non-destructive way.Single-spot mode PIXE with external proton beams of about half millimetre diameter was first used for a general characterisation of different areas of the painting. Differential PIXE performed in many spots led to reconstruct the sequence of paints employed by the artist and to estimate in some cases the local paint layer thickness.A second run carried out with the external scanning microbeam facility, using a 3 MeV proton beam of about 80 μm size, was then crucial to clarify some issues raised by the first analysis. In particular, elemental maps from selected areas helped to understand the way some colour shades had been obtained on the red mantle of the portrayed gentleman, using different pigments irregularly distributed on the surface.     

Applications of ion beam analysis in archaeology and the arts

Ion beam techniques are widely used for the nondestructive analysis of objects of art and archaeology. With simple, fast, and direct procedures practically all chemical elements present in the object can be identified, and determined quantitatively with good sensitivity, accuracy and precision. The external beam technique gives the possibility of examining all articles of any size and shape without sampling. Thus, valuable information can be obtained for the composition of the objects, for the fabrication techniques, the origin of materials, etc. This information may be used for purposes of historical interest, for restoration procedures, for identification of forgeries, and many other aspects. Examples are described briefly for dating by fluorine determination, for studies on coins ceramic surfaces, old paintings, etc.     

Examination of oil paintings by using a PIXE/PIGME combination

The applicability of the simultaneous use of particle induced X-ray and gamma-ray emission (PIXE/PIGME) for nondestructive analysis of art paintings has been investigated. By proper choice of detection geometry and proton energy the PIXE/PIGME combination yields almost covering elemental analysis of inorganic pigments even through the surface varnish of the painting. Accordingly the method is very suitable for example for a rapid detection of pallette errrors.     

X-ray microfluorescence analysis of pigments in decorative paintings from the sarcophagus cartonnage of an Egyptian mummy

This work characterized the elemental composition of the pigments used in decorative paintings from the sarcophagus cartonnage fragments of an Egyptian mummy, using μXRF with Synchrotron Radiation. This female mummy (n.158) is considered one of the most important pieces of the National Museum (Rio de Janeiro, Brazil) because of its unconventional embalming with legs and arms swathed separately. The measurements were performed at the XRF beamline D09B of the Brazilian Synchrotron Light Laboratory (LNLS), using white beam and a Si(Li) detector with resolution of 165 eV at 5.9 keV. The elements found in the samples were: Si, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Sr, Hg and Pb.     

Esterification by the Plasma Acidic Water:Novel Application of Plasma Acid

This work explores the possibility of plasma acid as acid catalyst in organic reactions. Plasma acidic water was prepared by dielectric barrier discharge and used to catalyze esterification of n-heptanioc acid with ethanol. It is found that the plasma acidic water has a stable and better performance than sulfuric acid, meaning that it is an excellent acid catalyst. The plasma acidic water would be a promising alternative for classic mineral acid as a more environment friendly acid.     

Experimental study on the air/water counter-current flow limitation in a model of the hot leg of a pressurized water reactor

An experimental investigation on the air/water counter-current two-phase flow in a horizontal rectangular channel connected to an inclined riser has been conducted. This test-section representing a model of the hot leg of a pressurized water reactor is mounted between two separators in a pressurized experimental vessel. The cross-section and length of the horizontal part of the test-section are (0.25 m × 0.05 m) and 2.59 m, respectively, whereas the inclination angle of the riser is 50°. The flow was captured by a high-speed camera in the bended region of the hot leg, delivering a detailed view of the stratified interface as well as of dispersed structures like bubbles and droplets. Countercurrent flow limitation (CCFL), or the onset of flooding, was found by analyzing the water levels measured in the separators. The counter-current flow limitation is defined as the maximum air mass flow rate at which the discharged water mass flow rate is equal to the inlet water mass flow rate.From the high-speed observations it was found that the initiation of flooding coincides with the formation of slug flow. Furthermore, a hysteresis was noticed between flooding and deflooding. The CCFL data was compared with similar experiments and empirical correlations available in the literature. Therefore, the Wallis-parameter was calculated for the rectangular cross-sections by using the channel height as length, instead of the diameter. The agreement of the CCFL curve is good, but the zero liquid penetration was found at lower values of the Wallis parameter than in most of the previous work. This deviation can be attributed to the special rectangular geometry of the hot leg model of FZD, since the other investigations were done for pipes.     

串联式放射性废水衰变池优化设计

为解决某医院核医学科放射性废水串联式衰变池结构不合理、死水区较大、不能使放射性核素有效停留衰变而导致放射性废水不能达标排放的问题，开展串联式衰变池的研究。利用三维流体模拟软件对串联式衰变池内部的水体流动规律、¹³¹I核素浓度分布、死水区体积等进行模拟研究，提出一种优化的串联式衰变池结构型式。结果表明，通过对串联式衰变池采取对角排水、增加折流板和折流板开孔、池底设置不同角度的倒角等结构优化措施，可使串联式衰变池排放口的放射性废水活度浓度低于10 Bq/L，最终实现达标排放。本研究结果可为后续放射性废水的处理提供参考。     

接枝丙烯酸聚乙烯表面诱导生成硫化镉及其形貌研究

分别以体积比为1∶1的异丙醇/水、甲醇/水混合溶剂作为接枝溶剂,通过调节丙烯酸单体浓度得到不同接枝率和不同表面接枝链分布的接枝膜,用接枝膜诱导形成了不同形貌特征的硫化镉.研究表明,接枝率越大,硫化镉在聚乙烯接枝膜表面的分布越密集;与甲醇/水为混合接枝溶剂相比,在异丙醇/水为混合接枝溶剂的接枝膜上的硫化镉颗粒分布比较均匀.     

Development of the analysis tool for the water cooling type passive residual heat removal system of Chinese pressurized reactor

An innovative design for Chinese pressurized reactor is the steam generator (SG) secondary side water cooling passive residual heat removal system (PRHRS). The new design is expected to improve reliability and safety of the Chinese pressurized reactor during the event of feed line break or station blackout (SBO) accident. The new system is comprised of a SG, a cooling water pool, a heat exchanger (HX), an emergency makeup tank (EMT) and corresponding valves and pipes. In order to evaluate the reliability of the water cooling PRHRS, an analysis tool was developed based on the drift flux mixture flow model. The preliminary validation of the analysis tool was made by comparing to the experimental data of ESPRIT facility. Calculation results under both high pressure condition and low pressure condition fitted the experimental data remarkably well. A hypothetical SBO accident was studied by taking the residual power table under SBO accident as the input condition of the analysis tool. The calculation results showed that the EMT could supply the water to the SG shell side successfully during SBO accident. The residual power could be taken away successfully by the two-phase natural circulation established in the water cooling PRHRS loop. Results indicate the analysis tool can be used to study the steady and transient operating characteristics of the water cooling PRHRS during some accidents of the Chinese pressurized reactor. The present work has very important realistic significance to the engineering design and assessment of the water cooling PRHRS for Chinese NPPs.