Handling spent nuclear fuel from the research reactors of the Russian Science Center Kurchatov Institute

Shipping out the spent fuel of the research reactors at the Institute for reprocessing is examined. The spent fuel is characterized by a great diversity of structural characteristics of the fuel assemblies and fuel elements, fuel compositions, and the enrichment, burnup, and cool-down times of the fuel as well as the state of the components of the assemblies and the structural materials. A classification and quantitative indicators of the accumulated spent fuel from the standpoint of the modern state of its reprocessing technology and the requirements for delivery to the Mayak Industrial Association are presented. The structural features of the TKU-19 and -128 shipment containers are presented, and the loading of spent fuel assemblies into them for shipment to reprocessing is described. The plans and goals of further work on the removal of spent fuel from the Institute’s territory are presented. Translated from Atomnaya énergiya, Vol. 106, No. 2, pp. 99–105, February, 2009.     

Decontamination of radioactively contaminated soil at the Russian Science Center Kurchatov Institute

The main results of startup operations and experimental operation of a facility for decontaminating radioactively contaminated soil are presented. The facility was developed on the basis of water-gravity and mechanical separation of soil, making it possible to separate the soil into fractions according to grain size and to identify and remove the finely dispersed fraction which is characterized by high specific activity and in which up to 90–95% of the radionuclides accumulate. The salient features of the technological and instrumentation scheme of the facility are described, and an assessment of its cost-effectiveness is presented. __________ Translated from Atomnaya énergiya, Vol. 103, No. 6, pp. 381–387, December, 2007.     

Rehabilitation of the radioactively contaminated objects and territory of the Russian Science Center Kurchatov Institute

This article is devoted to work done in 2002–2006 as part of the unified project Reabilitatsiya to rehabilitate radiation hazardous objects and sections of the radioactively contaminated territory of the Russian Science Center Kurchatov Institute. The main objects of the rehabilitation work were old storage sites built for radioactive wastes on the territory of the Institute when military and civilian nuclear technologies were under development. The structural features of the storage sites, including the volumes and characteristics of the wastes stored, are presented. The salient aspects of the disposal sites, taken into account during the rehabilitation work, are discussed. The organization of the rehabilitation operations and the sequence in which they are performed, the special features of the technical design solutions used, the technological methods, and ways for conducting the work are described. __________ Translated from Atomnaya énergiya, Vol. 102, No. 5, pp. 300–306, May, 2007.     

Inspection and preparation for liquidation of old radwaste repositories at the Russian Science Center Kurchatov Institute

Efforts to develop design materials and preparations for liquidation of old radwaste repositories at the Russian Science Center Kurchatov Institute have revealed problems due to the lack of archived information on the salient structural features of the repositories and the wastes placed there as well as due to the inadequate development of the technical and technological support base for restoration work. The technical approach implemented during the preparation for liquidation of the repositories is described. The sequence of operations is presented, and the technological and technical means are described. The problems of the technological support for inspection of the repositories are analyzed. __________ Translated from Atomnaya énergiya, Vol. 102, No. 6, pp. 374–377, June, 2007.     

Validation of analytical methods for nuclear spent fuel reprocessing

For more than 50 years, CETAMA, the Commission for establishment of analytical methods from the French Alternative Energies and Atomic Energy Commission, has provided Certified Reference Materials and Interlaboratory Comparisons for the development and validation of analytical methods in the nuclear field. In the future, the nuclear spent fuel reprocessing industry will require new standards and methods to comply with high content plutonium fuel and new extraction solvents. These standards and methods will have to be fully validated in order to ensure the quality of the analytical results obtained by the laboratories.In this context, a new ²⁴²Pu reference material, certified for its isotopic composition, has been recently produced. A novel statistical approach for data processing has been used and has led to a certified value of 0.985459 ± 0.000052 for the n(²⁴²Pu)/n(Pu) atomic ratio. In addition, an interlaboratory comparison has also been organized for the validation of a method for the analysis of DMDOHEMA, and its degradation products. This compound is considered as a new extractant candidate in the frame of separation processes for transmutation of long-lived radionuclides. The methodology and results obtained in both cases are presented.     

Work on a program for lowering fuel enrichment in research reactors to 19.7% at the Russian Science Center Kurchatov Institute

The work performed at the Russian Science Center Kurchatov Institute on the program for lowering the enrichment of fuel in research reactors is briefly described. The developed fuel assemblies and fuel elements with 19.7% ²³⁵U enrichment fuel, their testing in reactors, and post-reactor studies are described.     

Work on the program for lowering the fuel enrichment in research reactors to 36% at the Russian Science Center Kurchatov Institute

The work performed at the Russian Science Center Kurchatov Institute on the program for lowering the fuel enrichment in research and experimental reactors is briefly described. The designs of fuel assemblies and fuel elements containing fuel with 36% enrichment with ²³⁵U, their testing in reactors, and post-reactor studies are described.     

Extraction of radioactive wastes and liquidation of old repositories at the Russian Science Center Kurchatov Institute

The salient features of the organization and execution of the work performed to remove radioactive wastes from and rehabilitate ten old repositories located on a special site of the Institute, which were distinguished by their design and the form and composition of the wastes contained in them, are described. The old repositories were located close to a housing development, so that special attention was devoted to the choice of technologies and technical means used for the rehabilitation. The technical approach and the sequence of operations are presented, and the technology and technical means are described. The problems of providing the proper technological equipment for this work are analyzed. __________ Translated from Atomnaya énergiya, Vol. 103, No. 2, pp. 129–133 August, 2007.     

Critical benchmark experiments at the “Kurchatov Institute” Russian Scientific Center

Conclusion This brief review shows that the set of Russian data on the criticality of breeder systems, which has been well described and accepted by world society, is only a small part of the contribution of Russian scientific centers to the publication of scientific data on criticality, described and estimated at the level established by the ICSBEP. To all appearances, unpublished data contain a large number of results which could be useful for meeting the requirements of nuclear safety in the next ten years. At the same time, it is still possible to carry out new experiments on Russian assemblies, which is confirmed, in particular, by requests for several series of critical experiments at the “Kurchatov Institute” Russian Scientific Center. “Kurchatov Institute” Russian Scientific Center. Translated from Atomnaya énergiya, Vol. 84, No. 6, pp. 495–501, June, 1998.     

Monitoring homogeneous neutron absorbers during reprocessing of spent nuclear fuel

Bochvar All-Union Scientific-Research Institute for Standardization in Mechanical Engineering. Mayak Industrial Association. Translated from Atomnaya Énergiya, Vol. 72, No. 5, pp. 451–453, May, 1992.     

Preparations for decommissioning the MR research reactor at the Russian Science Center Kurchatov institute

The preparations of the MP research loop reactor for decommissioning are described. After final shutdown in 1993, a system of measures to ensure the required level of nuclear and radiation safety for the complex was implemented and a concept and fundamental program for decommissioning the reactor were developed. The variant DECON was taken as the base variant for decommissioning — immediate staged disassembly of structures and equipment, including disassembly of in-vessel structures of the RFT predecessor reactor which are stored in a central room of the reactor. The main results of the work performed to normalize the radiation conditions in the central room and to examine the safety-and-control system repository in this room are presented. __________ Translated from Atomnaya énergiya, Vol. 104, No. 5, pp. 259–264, May, 2008.     

A hot cell for the reprocessing of spent fuel samples

The hot cell for the reprocessing of spent fuel samples is suggested to be erected in the process hall of the radiochemical laboratory at Inchas. The design permits for safe handling of spent fuel samples with radioactivity level up to 10,000 MeV-Ci. The hot cell consists of an air-tight stainless steel box, 2 × 1.5 × 1.75 m³, surrounded by suitable biological shielding, and equipped with masterslave manipulators, lead glass window, and a number of gloves. The box is connected with a solid-waste disposal mechanism, and a feeding shute fo rtransferring the spent fuel samples into the hot cell. The cell is provided with a sliding door through which the stainless steel box can be easily withdrawn for maintenance or replacement. The ventilation of the hot cell ensures non-radioactivity release in the surrounding zones.     

Simulation of radioactive contamination transport by underground waters during the rehabilitation of old radwaste repositories at the Russian Science Center Kurchatov Institute

The results of auxiliary simulation for liquidation work performed at old radwaste respositories and rehabilitation of these sites, which included geological and geophysical investigations, monitoring, development of a database of hydrogeological conditions at a site and a detailed map with underground pipelines, are described. The models developed were used to determine the main areal of contamination and to obtain predictive estimates for different rehabilitation work scenarios. It is shown that assuming the liquidation of old repositories proceeds without incident the contamination areal will remain within the confines of the sites. __________ Translated from Atomnaya énergiya, Vol. 104, No. 2, pp. 115–118, February, 2008.