German operating plants

The German synthesis plants used the following naain operations ... 

A German example plant operates a pneumatical unit in a step-wise cycle. The sand is first dried by the introduction of heated air (5 min/220 °C). After this, the pneumatic cleaning is started by injecting of shots of compressed air (70 min.). This is followed by a final dedusting phase, during which only fluidising air is introduced (2 min). There is no need for fiirther cooling, since the sand cools down to a workable temperature. 

The processing cost of this technique for the German example plant is around EUR 60/toime. This high cost was the reason one operator closed his plant down and went back to the disposal of the water glass sand, which he could do for the lower cost of EUR 30Aonne. 

The European participants were questioned as to how they could be involved in a bilateral nuclear materials safety program. They had stated the proposed nuclear materials safety interactions would be beneficial to them. The most obvious contributions were that the Europeans could host site visits and tours in their operating plutonium facilities and discuss the safety systems and methods of actual operating plants. They could also support the attendance of their experts at future meetings on nuclear materials safety. It was suggested that the French-German-Russian trilateral mixed oxide fuel (MOX) project could be used as a possible way to initiate and involve the United States and remaining European parties. 

Hermann, F.J., B. Hermann, K.D. Kuhn, A.Van Schoor, M. Weishaupt, J. Furrer, and W. Knoch. 1996. Control of radioiodine at the German reprocessing plant WAK during operation and after shutdown, 24th DOE NRC Nuclear Air Cleaning and Treatment Conference, Portland, OR, July 15-18, 1996. 

Figure 12.3a illustrates an atmospheric pressure fixed-bed reactor used in German FT plants. The catalyst is located between vertical cooling plates, interconnected by horizontal cooling-water pipes. The heat of the reaction is led away from the catalyst by boiling water inside the pipes. The large-scale plants in Germany, France, and Japan were usually operated with these atmospheric pressure reactors. 

Current US experience shows that the magnitudes of the fuel rod deposits vary widely between plants. The fuel rods of newer German PWR plants, which were operated at pH levels around 7, all showed very thin and tightly adherent corrosion product deposits with a typical loading on the order of 2 to 3 10 mg/cm. As can be seen from Table 4.6., the main constituent of these deposits typically is iron, followed by nickel and chromium according to X-ray diffraction analyses, substituted spinels are the main component. The dominant radionuclide in these deposits is Co, followed by Mn and Co. From the specific activities of the radionuclides, in particular of Ni, an apparent residence time of the deposits in the neutron field of about 1 day was calculated (Siemens/KWU, unpublished). 

In 1994, cracks caused by intergranular stress corrosion cracking (IGSCC) were observed during visual inspection on some parts of the core internals in the oldest German BWR plant in operation, manufactured of niob-stabilized stainless steel. The intended replacement of the core shroud was not performed because of the economically motivated decision to decommission the plant. 

German vinyl ether plants were described in detail at the end of World War II and variations of these processes are stiU in use. Vinylation of alcohols from methyl to butyl was carried out under pressure typically 2—2.3 MPa (20—22 atm) and 160—165°C for methyl, and 0.4—0.5 MPa (4—5 atm) and 150—155°C for isobutyl. An unpacked tower, operating continuously, produced about 300 t/month, with yields of 90—95% (247). 

The MTO process employs a turbulent fluid-bed reactor system and typical conversions exceed 99.9%. The coked catalyst is continuously withdrawn from the reactor and burned in a regenerator. Coke yield and catalyst circulation are an order of magnitude lower than in fluid catalytic cracking (FCC). The MTO process was first scaled up in a 0.64 m /d (4 bbl/d) pilot plant and a successfiil 15.9 m /d (100 bbl/d) demonstration plant was operated in Germany with U.S. and German government support. 

Operating parameters of this German plant, on the basis of one cubic meter of raw gas, iaclude 0.139 m O2, 0.9 kg briquettes, 1.15 kg steam, 1.10 kg feed water, 0.016 kWh, and 1.30 kg gas Hquor produced. Gasifier output is 1850 m /h and gas yield is 1465 m /t dry, ash-free coal. The coal briquettes have a 19% moisture content, 7.8% ash content (dry basis), and ash melting poiat of 1270°C. Thermal efficiency of the gas production process is about 60%, limited by the quaHty and ash melting characteristics of the coal. Overall efficiency from raw coal to finished products is less than 50%. 

The German Lurgi Company and Linde A. G. developed the Rectisol process to use methanol to sweeten natural gas. Due to the high vapor pressure of methanol this process is usually operated at temperatures of -30 to -100°F. It has been applied to the purification of gas 1 plants and in coal gasification plants, but is not used commonlv natural gas streams. 

The German Gesellschaft fur Reaktorsicherheit (GRS) has a private arrangement with Rheinische Westalisches Elekrizitatswerke (RWE) to compile reliability data from an operating power plant, Biblis B. The data base contains failure rate, maintenance, and operational event data. External event data (floods, earthquake, fire, etc.) are compiled through a separate utility-sponsored data base. The data base provides information on repair and maintenance, and equipment performance. 

A vast majority of stractured catalysts and reactors are used in flue gas cleaning. However, due to proprietary reasons, not much information is provided. Babcock Power Environmental reported [65] that in the United States they have over 30000 MWs of SCRs commissioned, in design or evaluation, and under construction. BP s licensor has over 26000 MWs of SCRs operating in Europe. The German company EON operates 44 SCR systems, totaling 12 300 MWs. It should be noted that not all SCRs plants are based upon structured catalysts. 

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