Alzenau in Unterfranken, Germany
Alzenau in Unterfranken, Germany

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Brahler G.,NUKEM Technologies GmbH | Hartung M.,NUKEM Technologies GmbH | Fachinger J.,FNAG Furnaces Nuclear Applications Grenoble S.A.S. | Grosse K.-H.,FNAG Furnaces Nuclear Applications Grenoble S.A.S. | Seemann R.,ALD Vacuum Technologies GmbH
Nuclear Engineering and Design | Year: 2012

The application of High Temperature Reactor (HTR) Technology in the course of the continuously increasing world wide demand on energy is taken more and more under serious consideration in the power supply strategy of various countries. Especially for the emerging nations the HTR Technology has become of special interest because of its inherent safety feature and due to the alternative possibilities of applications, e.g. in the production of liquid hydrocarbons or the alternative application in H 2 generation. The HTR fuel in its various forms (spheres or prismatic fuel blocks) is based on small fuel kernels of about 500 μm in diameter. Each of these uranium oxide or carbide kernels are coated with several layers of pyrocarbon (PyC) as well as an additional silicon carbide (SiC) layer. While the inner pyrocarbon layer is porous and capable to absorb gaseous fission products, the dense outer PyC layer forms the barrier against fission product release. The SiC layer improves the mechanical strengths of this barrier and considerably increases the retention capacity for solid fission products that tent to diffuse at these temperatures. Especially the high quality German LEU TRISO spherical fuel based on the NUKEM design, has demonstrated the best fission product release rate, particular at high temperatures. The ∼10% enriched uranium triple-coated particles are embedded in a moulded graphite sphere. A fuel sphere consists of approximately 9 g of uranium (some 15,000 particles) and has a diameter of 60 mm. As the unique safety features, especially the inherent safety of the HTR is based on the fuel design, this paper shall reflect the complexity but also developments and economical aspects of the fabrication processes for HTR fuel elements. © 2011 Elsevier B.V.

Today, designers of new WER reactors as well as companies operating Russian NPP favour direct methods of waste management for treating wastes of different categories generated during plant operation. The objective is to achieve the amount of 50 m 3 of conditioned waste per one reactor unit per year, which is currently being discussed internationally. NUKEM Technologies has reviewed the existing waste management concepts and proposed improved waste management technologies. The first step was to identify the waste prevention policies. The waste management concept focuses on subjecting different liquid wastes to different treatment methods. Another objective was to minimise the organic content in conditioned waste. The treatment methods for solid radioactive waste include high force compaction and incineration. The new concept also features a tracking system which is used for classifying the incoming waste and ensuring its traceable documentation at different stages throughout the entire treatment process. Additionally, each waste package prepared for final storage is monitored before it leaves the treatment building and provided with an individual certificate containing all data about the treated waste including its radiological characteristics and the place of storage.

Brahler G.,NUKEM Technologies GmbH | Slametschka R.,NUKEM Technologies GmbH
ATW - Internationale Zeitschrift fur Kernenergie | Year: 2011

Ion exchangers are employed in all nuclear power plants with water loops to remove radionuclides from the primary coolant. Cation and anion exchangers are used as coarse-grained spherical resins in pressurized water reactors and as finely ground powder resins in boiling water reactors. In new plants there is a trend to exploit all possibilities of avoiding contaminated liquids and, should solutions occur nevertheless, clean them by ion exchange to such an extent that they can be disposed of as non-radioactive waste. This means less use of evaporator facilities or even giving them up altogether. Regeneration, which is possible in principle, is hardly employed at all. As a rule, ion exchangers consist of cross-linked polystyrene. As no use is made of regeneration in nuclear power plants, unlike conventional technology, the material must be disposed of as radioactive waste. In this connection, it is important to bear in mind that spent ion exchangers are too moist for direct disposal and are made up of inorganic matter. Consequently, a process is needed which reduces volume, produces an inert or mineralized product, works at temperatures not exceeding approx. 600 °C, and can be run in a simple plant. NUKEM further developed a pyrolysis technique known from other technical applications. These ion exchangers can be decomposed by pyrolysis very effectively; the product is inert and chemically resistant. No additives are needed. The entire radioactivity inventory remains in the pyrolysate. The pyrolysate is a flowable solid. This makes it easy to handle and allows it to be compacted or cemented, depending on interim and repository storage conditions and on the activity inventory.

Eichhorn H.,NUKEM Technologies GmbH
ATW - Internationale Zeitschrift fur Kernenergie | Year: 2011

After an international tendering process NUKEM was awarded to build the Industrial Complex for Solid Radwaste Management (ICSRM) at the Chernobyl Nuclear Power Plant. The ICSRM project is one component of an integrated radioactive waste management programme for the entire Chernobyl Nuclear Power Plant (ChNPP). The Project includes radioactive waste retrieval, processing and packaging for interim storage or final disposal. Waste management operations performed as part of the ICSRM Project include the following: Waste volume reduction through compaction and incineration. Waste solidification through immobilization in concrete, also known as grouting. The immobilization material provides good resistance to external factors, such as water and weather. Also, grouting creates a monolith with few voids, thus ensuring the integrity of the waste form. NUKEM is the first western company who has successfully accomplished a radwaste treatment plant within the ChNPP site. NUKEM has received all payments from the EC due to the final acceptance of the facilities. In addition to the main contract NUKEM has successfully accomplished a contract regarding the ventilation system of LOT 0. Based on the ICSRM success NUKEM is currently executing other projects in Ukraine and is involved in several tenders.

Scheffler B.,NUKEM Technologies GmbH
ATW - Internationale Zeitschrift fur Kernenergie | Year: 2011

Management of radioactive waste, handling spent fuel elements, decommissioning of nuclear facilities, and engineering and consulting activities are services associated with the name of NUKEM all over the world. The company's scientists and engineers develop solution concepts combining the latest technologies with proven techniques and many years of experience. The company's history and the services offered to the nuclear industry began more than 5 decades ago. The predecessor, NUKEM Nuklear-Chemie-Metallurgie, was founded in 1960 as one of the earliest nuclear companies in Germany. Originally, the firm produced fuel elements for a variety of reactor lines. As early as in the 1970s, logical extensions of these business activities were nuclear engineering and plant construction. In the meantime, NUKEM Technologies GmbH has developed a worldwide reputation for its activities. Numerous reference projects bear witness to optimum project management and customer satisfaction. Since 2009, NUKEM Technologies has been a wholly owned subsidiary of the Russian Atomstroyexport. NUKEM Technologies operates sales and project offices outside Germany, e.g. in Russia, China, Lithuania, France, and Bulgaria. In this way, the company is present in its target markets of Russia, Western and Eastern Europe as well as Asia, offering customers and partners fast and direct contacts.

Traichel A.,NUKEM Technologies GmbH | Tardy F.,Électricité de France | Mummert M.,NUKEM Technologies GmbH
International Conference on Nuclear Engineering, Proceedings, ICONE | Year: 2014

A general overview of the existing radioactive inventory in the plant is necessary for the decommissioning of nuclear power plants. Based on the knowledge about radiological inventory, appropriate decommissioning techniques and procedures can be specifically used. In order to derive the existing radiological activity in the facility a study was carried out to obtain a representative overview of the total radiological situation at the NPP. Within a study a generic methodology for the radiological characterization was developed. This methodology has been applied on the CO2-circuit of the gas-cooled, graphitemoderated reactor Chinon A2 (MAGNOX type). This paper covers the implementation of an approach for characterisation of radiological inventory for decommissioning. The approach aims at the definition of the number and distribution of local sampling, required measurements as well as suitable measurement systems leading to a confident result with minimized effort in sampling. The paper covers two main objectives: 1. Methodology at and 2. Determination of radiological inventory based on measured data. The proposed methodology is a stepwise procedure which offers the possibility for minimizing the number of required measurements/sample analyses. At the first step the underlying system is an "as-simple-as-possible"-example with homogeneous contamination. In a second step the methodology is expanded to a more realistic and complex system, for which additional investigations have to be performed. The determination of the radiological inventory using the methodology has to consider a given confidence level and maximum allowed error. Therefore statistical assessment is widely used in estimations. Copyright © 2014 by ASME.

Sokcic-Kostic M.,NUKEM Technologies GmbH | Langer F.,NUKEM Technologies GmbH | Schultheis R.,NUKEM Technologies GmbH
Proceedings of the International Conference on Radioactive Waste Management and Environmental Remediation, ICEM | Year: 2011

Low and intermediate level radioactive waste must be sorted and treated before it can be sent to radioactive waste storage. The waste must fulfil an extensive amount of acceptance criteria (WAC) to guarantee a safe storage period. NUKEM Technologies has a broad experience with the building and management of radioactive waste treatment facilities and has developed methods and equipment to produce the waste packages and to gather all the required information. Copyright © 2011 by ASME.

Buttner K.,NUKEM Technologies GmbH | Slametschka R.,NUKEM Technologies GmbH
Proceedings of the International Conference on Radioactive Waste Management and Environmental Remediation, ICEM | Year: 2011

According to the framework program of the Russian Federation released in 2010 it is planned to build up additional nuclear capacity of approximately 20 GWe. In addition, contracts were signed for several new-builds throughout the world. The related design efforts together with the restricted design capacities in Russia led Rosenergoatom (Client) and Atomstroyexport (Co-Client) to the set up of a so-called unified project "TOI". "TOI" means translated "Technically Optimized reactor designed with Integrated databases". NUKEM Technologies owned by Atomstroyexport was selected to develop the standardized technically optimized design for the treatment of the generated LLW and ILW. Special emphasis was made to reduce the waste volume for storage after treatment to below 50 m3 per year and unit. The selected treatment technologies compromise sorting, fragmentation, thermal treatment, compaction, evaporation, cementation etc. In 2010 NUKEM Technologies together with Atomenergoprojekt (Main Contractor) developed the technical concept for the treatment of liquid and solid LLW and ILW generated within the reactor as well as in the auxiliary buildings. In an iterative process the waste amounts generated and the respective treatment methods were discussed and agreed. The next step will be to further develop the design. The basic design (technical project) should be finalized until end of 2012. Copyright © 2011 by ASME.

There has been a change of mind with respect to waste management among power plant operators in Russia and planners of the new WER reactor line. Solid waste no longer is to be stored on the site of the power plant; instead, a functioning direct method of treatment of the different categories of waste arising in operation is favored. Waste conditioning and reduced storage volumes are indispensable arguments in selling reactor technology to markets outside Russia. Reference often is made to the internationally discussed volume of 50 m3 of waste per reactor unit and year, which is then defined as a target. NUKEM Technologies verified existing technical concepts and worked out proposals of improved waste management. One project proposal accepted by ASE (Atomstroyexport) was elaborated to the Technical Project (corresponding to Basic Design) status. Specific management of materials flows, the use of processes tailored to the waste stream, and adaptation of the throughputs of these plants to the waste arisings actually expected are able to reduce clearly both the volume of conditioned waste to be stored and the capital costs.

Bienia H.,NUKEM Technologies GmbH | Noll T.,NUKEM Technologies GmbH
ATW - Internationale Zeitschrift fur Kernenergie | Year: 2012

A share of approx. 80 % nuclear electricity makes France the country with the world's largest proportion of nuclear electricity. A considerable number of French plants were commissioned more than 30 years ago. At the present time, 58 nuclear power plants out of this population are in operation, twelve have already been decommissioned and are about to be, or are being, demolished. France thus is one of the most interesting and most dynamic countries as far as future demolition projects are concerned. Current demolition projects in France have a kind of model or pilot character for the future French demolition strategy and are under particularly close supervision and inspection by the operator, Electricity de France. One of these projects is the current demolition of the CCycooled heavy water reactor (EL 4) of Brennilis in Brittanny which was decommissioned in 1985. Demolition of the reactor, its primary system and ancillary systems is handled by a Franco-German consortium composed of ONET Technologies Grands Projets, France, and NUKEM Technologies, Germany. Because of the special design features of the Brennilis reactor and the boundary conditions this created, it was not possible in many cases to transfer directly German demolition techniques. The demolition technique adopted is based on the use of remotely operated robot systems not only performing disassembly but, step by step, also building up infrastructure of their own in the reactor compartment as demolition progresses. Besides the special technical features and challenges arising in this project there are also differences in licensing regulations and cultural differences which play a major role. The report concludes with a brief summary of experience accumulated.

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