Processes for the Preparation of High-Purity Arsenic and Its Compounds

Inorganic Materials - This paper presents results of analysis of the patent, scientific, and technical literature concerned with the physicochemical and technological foundations of the preparation...     

Modeling condensation heat transfer on a horizontal finned tube in the presence of noncondensable gases

European designs for the next generation of nuclear reactors incorporate innovative passive systems in their containments to enhance heat removal by condensation under postulated accident conditions. These systems consist of several units of cross-flow finned tube bundles internally cooled with water. So far most of the studies that have been addressed to the issue of heat transfer onto finned surfaces under condensing conditions have involved refrigerants and pure vapor conditions. This study presents a model (HTCFIN) capable of predicting condensation of a cross-flow air–steam mixture onto a single horizontal finned tube. The comparison of HTCFIN predictions to the available databases shows its acceptable accuracy in a wide range of conditions and allows an interpretation of the influence of major variables acting on the scenario. As a consequence, HTCFIN model represents a step forward in the present theoretical capability to estimate heat transfer within containments of next generation of European reactors in the case of a hypothetical accident.     

Materials-technology investigations of fuel elements, irradiated in a reactor at the obninsk nuclear power plant, after standing for 38 years in a depository

The results of materials-technology investigations of a spent fuel assembly from a reactor at the Obninsk nuclear power plant, the first nuclear power plant in the world, before the rated burnup and after prolonged dry storage (for about 40 years) were presented. It was established that the fuel elements from the fuel assembly studied are in satisfactory condition. No appreciable damage due to the prolonged storage was found: the outer diameter remains within the technological tolerance limits and the strength and the plasticity of the jackets are high. Only surface corrosion damage to 10 μm depth was found on the fuel-element jackets. The fuel composition remained whole. 6 figures, 1 table, 3 references. State Science Center of the Russian Federation—A. I. Leipunskii Physics and Power-Engineering Institute. Translated from Atomnaya énergiya, Vol. 88, No. 3, pp. 183–188, March, 2000.     

Nuclear Power Plant Safety and Strength of Equipment Components with Service-Life Extension of First-Generation Power-Generating Units

The safety of nuclear power plants and the strength of the components of the first-loop equipment operating under pressure are examined together. The problem is analyzed for an actual situation with possible extension of the operational service life of the first-generation power-generating units. Since it is impossible to upgrade the first-generation units, in accordance with modern safety requirements, effective compensating measures at other stages of a multistage protection system must be formulated and implemented in the form of appropriate protection and containment safety systems. It is suggested that as one such measure special attention be focused on the diagnostics of the service life of equipment taking account of the design and real cyclic and other loads which occur. 9 references.     

Theorie der Glimmentladung

Zusammenfassung Die Annahme, daß eine wesentliche Zahl von Elektronen und Ionen sich im Gasraum zu neutralen Molekülen vereinigen kann, führt zu einer Deutung der wesentlichen Erscheinungen der Glimmentladung. Insbesondere werden Stabilität, Feldverlauf und Charakteristik der Entladung qualitativ verständlich.Für die Weiterentwicklung der Theorie ist eine genauere Kenntnis der Ionenbeweglichkeit und der Ionisations- und Rekombinationsvorgänge erwünscht.     

EFFECT OF GLASS COLOR ON SETTING RATES IN MANUFACTURE OF GLASS BOTTLES *

It has been observed in the manufacture of bottles of the same size and shape from various colored glasses, such as emerald green and amber and the so-called flint bottle glass, that higher machine speeds are usually obtained in the case of the colored glasses. A laboratory test has been devised to measure the cooling rates of several colored and colorless glasses throughout their respective working ranges, which gives results paralleling the speeds obtained in actual bottle manufacture.