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This paper describes the conceptual design of a 600MW HTGR-GT power plant which has been completed in the framework of the HTGR-GT feasibility study project. The project is assigned to JAERI by the Science and Technology Agency in Japan. The inlet and outlet gas temperatures in the reactor are 460°C and 850°C, respectively. Helium gas pressure is 6MPa. The gas turbine system type is intercooled recuperative direct cycle. Designs of helium turbine, LP and HP compressors and generator are presented. Efforts have been focussed on reducing their dimensions and weight in the preliminary design to facilitate the mechanical design of the rotor and also reduce the size of power conversion vessel. Rotor dynamics behavior and maintenance procedures of the horizontal single-shaft configuration adopted are explained.

SynopsisThe fine structure of cotton cellulosic fibers carbamoylethylated and carboxyethylated at 30 and 2OoC in the presence of 3% and 20% sodium hydroxide was investigated by measuring moisture regain, water imbibition, x-ray photograph, degree of crystallinity, spacing, and crystallite size under dry and wet conditions. As carbamoylethyl and carboxyethyl substituents are introduced in amorphous regions of the samples reacted with acrylamide in 3% sodium hydroxide, the fine structure of the crystalline regions is not affected by the reaction. On the other hand, in the samples reacted in 2W0 sodium hydroxide, the substituents are introduced not only in amorphous regions but also in crystalline regions to make them disordered. Although spacing between ( l O i ) planes does not change, spacing between (101) planes increases by the reaction in 20% sodium hydroxide. Comparing crystallite sizes normal to (hkl) planes under dry conditions with those under wet conditions, it is supposed that cohesive forces between (101) planes are different from those between (107) planes, and the former is hydrogen bonds and the latter resemble Van Der Waals forces. As a result, carbamoylethyl and carboxyethyl groups are introduced selectively between (101) planes.

This paper presents basic data on the effect of a high-frequency induction coil in the levitation-melting method.The buoyant force is measured with a digital balance under the constant 30 k W output, and the effect of the coil's position on the buoyancy is investigated experimentally. I n addition, the flux distribution In the actual coil, which has asymmetric shape, is calculated with the three-dimensional boundary element method. The rotating motion of a levitating metal caused by a n asymmetric flux distribution is discussed.In this paper, we show that controlling the movement of ingot may be a solution to the problem of uniform heating in this system. I. INTRODUC~~ONIn recent years, the melting technique has become very important in improving quality of metal and in developing a new material. In the conventional melting method, various kinds of crucibles suited to metal are usually adopted. However a reaction usually takes place between the molten metal and crucible.To solve the problem, a cold crucible method was proposed in Germany in 1950 [l]. This method is very useful in melting metal without contamination, because the molten metal is levitated by an electromagnetic force in space. The copper cold crucible is comprised of several segments, which are cooled internally with water. The metal crucible is placed in a high-frequency induction coil, and an ingot in the crucible is melted by induction heating. Because a repulsing magnetic force is induced between the molten metal and cold crucible, the position of the molten metal is stabilized. Since the cold crucible is one kind of flux concentrator, the effective magnetic flux density also increases in comparison to that without the crucible [2].However this method has some problems, and this equipment is not used generally yet. There are some difficulties in the levitation of molten metal in the liquid state, a restriction of the melting quantity (that is a limitation of the levitating quantity), and a problem in controlling the temperature 13-51. Our research has concentrated on the issue of the quantity of metal that can be levitated, and we have Manuscript received April 18, 1995.developed some improvements in the levitation-melting technique. While the principle of this method is clear, there are still many difficulties in a practical implementation of this technique. This paper presents basic data on effect of a high-frequency induction coil. Fig. 1 shows the shape of the cold crucible and the highfrequency inductioncoil. The copper cold crucible has eight segments, which are cooled internally with water. The sixturn exciting coil is double winding with copper tube. Fig. 2 shows the definition of parameters used in this measurement. The sample is a steel ball of diameter 43 mni, 2868 in weight. The metal was inserted into the crucible with a ceramic holder, and supported at the center of coil HI. The metal was levitated at upper part of HI after preheating 27 kW for 20 sec. suction 1/ Cooling water poker supply 'egmentr Cold crucible Fig. 1 Shape of the...

SynopsisA new sampling method has been developed fo r the determination of hydrogen in liquid steel. The sampler employed is a newly designed evacuated one which consists of an outer quart z tube and a well-jiUed inner tube of degassed austenitic stainless steel.In the new procedure developed, liquid steel is aspirated directly from the steel bath in industrial operation into the inner stainless steel tube, quenched in water, and treated in the same way as in the convmtional rapid-quench methods. The sample is analyzed for hy drogen by the vacuum hot-extraction method as it is covered with the stainless steel tube.Comparative investigations of the newly developed sampler with the conventional evacuated quart z tube sampler have revealed that the former gives increasingly higher analytical resuits than the laUer does as the hydrogm content in liquid steel increases . It has been conjirmed that the stainless steel tube in the new sampler prevents losses of hydrogen from the asp irated sample, and accordingly more accurate resuits are obtained.Furthermore, some problems of sample preparation and blank determination which occurred in the analytical p rocedure of the new method have been investigated and a satisfactory p rocedure has been established. Analyzer Type SHO-II. The a n alyzer was so rem odeled by the authors that the fusion-extraction sys-Research Article ( 546 ) Transactions ISH, Vol. 20, 1980