scholarly journals Perspective Schemes of Conditioning of Liquid Radioactive Waste of Ukrainian Nuclear Power Plants

2020 ◽  
Vol 18 ◽  
pp. 48-56
Author(s):  
Yu. A. Olkhovyk ◽  
Keyword(s):  
Radioactive Waste ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Liquid Radioactive Waste ◽  
Ventilation System ◽  
Salt Cake ◽  
Safe Level ◽  
Time Required ◽  
Storage Facilities

The existing world experience of practical use of sorption technology and technology of cementing liquid borne radioactive waste of nuclear power plants (NPP) with water-water energetic reactors (WWER) to obtain a product 1suitable for transfer to disposal facilities is considered. It has been concluded that salt cake accumulated in NPP storage facilities is a major problem that determines the further choice of the development and implementation of conditioning technologies. Currently, 18,000 salt cake containers stored at the Zaporizhzhia NPP and Khmelnitskiy NPP storage facilities have exceeded their design life. A possible solution is to change the classification of the salt cake and to classify it as solid radioactive waste. It is noted that the existing tax system for the generation of radioactive waste in Ukraine does not contribute to the choice of conditioning technologies aimed at minimizing the volume of the final product. The prospect of application of the technology of melting in the “cold crucible” for one-stage formation from a evaporator bottoms and salt cake borosilicate glass, guaranteed capable in the conditions of surface disposal to ensure the isolation of radionuclides during the time required for decay to a safe level of radioactivity. It is proposed to create a melting unit according to the modular scheme, when several parallel crucibles with capacity up to 20 kg/h with cheaper highfrequency generators with a capacity of 160 kW are connected to common ventilation system. The urgency of carrying out technical and economic analysis to determine the optimal 56 ISSN 2311-8253 Nuclear Power and the Environment № 3 (18) 2020 solutions for the introduction of effective and economically sound technologies for the processing of evaporator bottoms and salt cake at Ukrainian NPPs is emphasized.

scholarly journals Development of Technologies for Handling Liquid Radioactive Waste of Nuclear Power Plants

2020 ◽  
Vol 13 (4) ◽  
pp. 90-98
Author(s):  
R. A. Penzin ◽  
◽  
A. A. Svitsov ◽  
Keyword(s):  
Radioactive Waste ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Liquid Radioactive Waste ◽  
Selective Decontamination ◽  
Drastic Reduction ◽  
Treatment Technologies ◽  
New Generation

The paper presents the results of a feasibility study focused on two methods designed to treat evaporator bottoms generated from the evaporation of liquid radioactive waste (LRW) at nuclear power plants (NPP), namely, deep evaporation (DE) and ion-selective decontamination (ISD). ISD method proved to be much more efficient and costeffective compared to the DE one due to a drastic reduction of the conditioned radioactive waste volume intended for disposal. The paper also considers possible opportunities for upgrading particular ISD stages. It provides recommendations on how to upgrade LRW treatment technologies at NPP of a new generation, including separated collection of basic LRW types and development of in situ RW processing and conditioning flowsheets.

The Influence of Chemical Composition of Liquid Radioactive Waste on the Evaporation Process

2000 ◽  
Vol 663 ◽  
Author(s):  
P.P. Poluektov ◽  
L.P. Soukhanov ◽  
M.I. Zhicharev
Keyword(s):  
Nitric Acid ◽  
Chemical Composition ◽  
Radioactive Waste ◽  
Nuclear Power ◽  
Power Plants ◽  
Liquid Radioactive Waste ◽  
Salt Content ◽  
Evaporation Process ◽  
Simplified Models ◽  
Salt Systems

ABSTRACTA method is suggested to assess the tolerable salt content of the evaporator bottoms from the data on solubility in salt systems taken as simplified models of liquid radioactive waste (LRW) arising from nuclear power plants (NPP) with boiling reactors. It has been demonstrated that the degree of evaporation may be substantially increased by implementing the process in nitric acid. Equations have been derived that allow the calculation of the minimum needed acidity of the solution to allow maximum evaporation.

Cold Crucible Vitrification of NPP Operational Waste

2002 ◽  
Vol 757 ◽  
Author(s):  
Feodor A. Lifanov ◽  
Michael I. Ojovan ◽  
Sergey V. Stefanovsky ◽  
Rudolf Burcl
Keyword(s):  
Radioactive Waste ◽  
Nuclear Power ◽  
Power Plants ◽  
Glass Melting ◽  
Liquid Radioactive Waste ◽  
Specific Radioactivity ◽  
Melting Process ◽  
Specific Power ◽  
Cold Crucible ◽  
Minimal Impact

ABSTRACTOperational radioactive waste is generated during routine operation of nuclear power plants (NPP). This waste must be solidified in order to ensure safe conditions of storage and disposal. Vitrification of NPP operational waste is a relative new solidification option being developed for last years. The vitrification technology comprises a few stages, starting with evaporation of excess water from liquid radioactive waste, followed by batch preparation, glass melting, and ending with vitrified waste blocks and some relative small amounts of secondary waste. Application of induction high frequency cold crucible type melters facilitates the melting process and significantly reduces the generation of secondary waste. Two types of glasses were designed in order to vitrify operational waste depending on the reactor type at the NPP. For the NPP with RBMK-type reactors the glass 16.2Na2O 0.5K2O 15.5CaO 2.5 Al2O3 1.7Fe2O3 7.5B2O3 48.2SiO2 1.1 Na2SO4 1.2NaCl (5.7 others) was produced. For NPP with WWER reactors the glass 24.0Na2O 1.9K2O 6.2CaO 4.3Al2O3 1.8Fe2O3 9.0B2O3 46.8SiO2 0.8Na2SO4 0.9NaCl (4.3 others) was produced. The melting temperatures of both glass formulations were 1200–1250 C, specific power consumption was 5.2 ± 0.8 kW h/kg, 137Cs loss was within the range 3 - 4 %. The specific radioactivity of glass reached 7.0 MBq/kg. Glass blocks obtained were studied both in laboratory and field conditions. Long-term studies revealed that vitrified NPP operational waste has the minimal impact onto environment. Since the glass has excellent resistance to corrosion it gives the basic possibility of maximal simplification of engineered barrier systems in a disposal facility. The simplest disposal option for vitrified NPP waste is to locate the packages directly into earthen trenches provided the host rock has the necessary sorption and confinement properties.

Utilization of Radioactive Waste for Solidifying Material to Fill Waste Forms

2001 ◽  
Author(s):  
Takeshi Ishikura ◽  
Daiichiro Oguri
Keyword(s):  
Radioactive Waste ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Filling Ratio ◽  
Improved Method ◽  
Low Level ◽  
Waste Forms ◽  
Disposal Facility ◽  
Low Level Radioactive Waste

Abstract Minimizing the volume of radioactive waste generated during dismantling of nuclear power plants is a matter of great importance. In Japan waste forms buried in shallow burial disposal facility as low level radioactive waste (LLW) must be solidified by cement with adequate strength and must extend no harmful openings. The authors have developed an improved method to minimize radioactive waste volume by utilizing radioactive concrete and metal for mortar to fill openings in waste forms. Performance of a method to pre-place large sized metal or concrete waste and to fill mortar using small sized metal or concrete was tested. It was seen that the improved method substantially increases the filling ratio, thereby decreasing the numbers of waste containers.

Planning of Large-Scale In-Situ Gas Generation Experiment in Korean Radioactive Waste Repository

2010 ◽  
Author(s):  
Juyoul Kim ◽  
Sukhoon Kim ◽  
Jin Beak Park ◽  
Sunjoung Lee
Keyword(s):  
Radioactive Waste ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Large Scale ◽  
Radioactive Waste Disposal ◽  
Gas Generation ◽  
Radioactive Waste Repository ◽  
Waste Repository

In the Korean LILW (Low- and Intermediate-Level radioactive Waste) repository at Gyeongju city, the degradation of organic wastes and the corrosion of metallic wastes and steel containers would be important processes that affect repository geochemistry, speciation and transport of radionuclides during the lifetime of a radioactive waste disposal facility. Gas is generated in association with these processes and has the potential threat to pressurize the repository, which can promote the transport of groundwater and gas, and consequently radionuclide transport. Microbial activity plays an important role in organic degradation, corrosion and gas generation through the mediation of reduction-oxidation reactions. The Korean research project on gas generation is being performed by Korea Radioactive Waste Management Corporation (hereafter referred to as “KRMC”). A full-scale in-situ experiment will form a central part of the project, where gas generation in real radioactive low-level maintenance waste from nuclear power plants will be done as an in-depth study during ten years at least. In order to examine gas generation issues from an LILW repository which is being constructed and will be completed by the end of December, 2012, two large-scale facilities for the gas generation experiment will be established, each equipped with a concrete container carrying on 16 drums of 200 L and 9 drums of 320 L of LILW from Korean nuclear power plants. Each container will be enclosed within a gas-tight and acid-proof steel tank. The experiment facility will be fully filled with ground water that provides representative geochemical conditions and microbial inoculation in the near field of repository. In the experiment, the design includes long-term monitoring and analyses for the rate and composition of gas generated, and aqueous geochemistry and microbe populations present at various locations through on-line analyzers and manual periodical sampling. A main schedule for establishing the experiment facility is as follows: Completion of the detailed design until the second quarter of the year 2010; Completion of the manufacture and on-site installation until the second quarter of the year 2011; Start of the operation and monitoring from the third quarter of the year 2011.

Optimization of Concrete Container Composition in Radioactive Waste Management

1985 ◽  
Vol 50 ◽  
Author(s):  
I. B. Plecas ◽  
Li. L. Mihajlovic ◽  
A. M. Kostadinovic
Keyword(s):  
Mechanical Properties ◽  
Radioactive Waste ◽  
Waste Management ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Leakage Rate ◽  
Intermediate Level ◽  
Radioactive Waste Management ◽  
Intermediate Level Radioactive Waste

AbstractIn this paper an optimization of concrete container composition, used for storing low and intermediate level radioactive waste from nuclear power plants in Yugoslavia, is presented.Mechanical properties 37−52 MPa, permeability 1.07. 10−13 - 1.50. 10−11cm2 and leakage rate 3.66. 10−6 - 1.77. 10−4 cm/d for concrete made of commercial materials, were tested.

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