scholarly journals Aluminosilicate Sediment Dissolution in Liquid Radioactive Waste Storage Facilities

2020 ◽  
Vol 11 (2) ◽  
pp. 75-84
Author(s):  
T. A. Kulagina ◽  
◽  
V. A. Kulagin ◽  

The article deals with the extraction of insoluble sediments formed in storage tanks during long-term storage of liquid radioactive waste from spent nuclear fuel reprocessing. Results of a thermodynamic analysis are presented enabling to assess the structure of the precipitation formed and to select most effective modes for thermal and hydrodynamic effects (cavitation technology) produced by liquid medium on eroded sediments. The paper presents the results of studies on the extraction of poorly soluble pulp components from storage tanks using cavitation technology.

Author(s):  
John Rowat

Storage and disposal of radioactive waste are complementary rather than competing activities, and both are required for the safe management of wastes. Storage has been carried out safely within the past few decades, and there is a high degree of confidence that it can be continued safely for limited periods of time. However, as the amounts of radioactive waste in surface storage have increased, concern has grown over the sustainability of storage in the long term and the associated safety and security implications. In response to these concerns, the IAEA has prepared a position paper [1] that is intended for general readership. This presentation will provide a summary of the position paper, and a discussion of some safety issues for further consideration. A key theme is the contrast of the safety and sustainability implications of long term storage with those of early disposal. A number of factors are examined from different points of view, factors such as safety and security, need of maintenance, institutional control and information transfer, community attitudes and availability of funding. The timing and duration of the process of moving from storage to disposal, which are influenced by factors such as the long timeframes required to implement disposal and changing public attitudes, will also be discussed. The position paper focuses on the storage of three main types of waste: high level waste from the reprocessing of nuclear fuel, spent nuclear fuel that is regarded as waste and long-lived intermediate level radioactive waste. Long term storage of mining and milling waste, and other large volumes of waste from processes involving the use of naturally occurring radioactive materials are not discussed. Specialist meetings were held last year by the IAEA on the sustainability and safety of long-term storage to establish and discuss the issues where a broad consensus exists, and to investigate areas where issues remain unresolved. Within the technical community, it is widely agreed that perpetual storage is not considered to be either feasible or acceptable because of the impossibility of assuring active control over the time periods for which these wastes remain potentially hazardous. For high-level and long-lived radioactive waste, the consensus of the waste management experts is that disposal in deep underground engineered facilities — geological disposal — is the best option that is currently available, or likely to be available in the foreseeable future.


2020 ◽  
Vol 19 (4) ◽  
pp. 31-38
Author(s):  
K. K. Yaroshenko ◽  
◽  
B. G. Shabalin ◽  
G. M. Bondarenko ◽  
◽  
...  

The article highlights the problem of reprocessing of liquid radioactive waste (LRW) from the Ukrainian nuclear power plants with VVER reactors. The main method of these LRW treatment is distillation (evaporation) and ion exchange sorption. The final products of LRW processing by distillation are distillation residues, spent sorbents and sludges, and salt melt with significant radioactivity accumulated in large volumes, which do not meet the long-term storage and disposal criteria. So, it is necessary to develop a new, more efficient LRW treatment scheme that can solve the problems of large volumes of LRW and transfer waste to a state suitable for long-term storage and disposal. One of the important and challenging problems of LRW treatment is the presence of organic components (ethylenediaminetetraacetic acid (EDTA), oxalic acid, synthetic surfactants (SPAR) in the waste, since these substances complicate removal of radionuclides from the LRW. The results of investigation of ozonolysis conditions of LRW organic components are presented on the example of a model solution with imitated solutions of disodium salt of ethylenediaminetetraacetic acid and ethane diacid. It was established, that ozonation of organic components of LRW results in decreasing of pH value, which causes reduction of their destruction efficiency. Control of the pH values at the initial level (11−12 units) by permanent alkalifying can increase the ozonolysis efficiency of LRW organic components in 30%. EDTA is better destructed by ozone than ethane diacid. Destruction of LRW organic components progresses in two stages: the first is fast and second is low. The maximum of EDTA destruction degree, in the experimental conditions, was 86%; destruction degree of ethane diacid — 51%; maximum of LRW model solution organic components (EDTA, ethane diacid, synthetic surface-active reagent) destruction degree was 67%. Due to co-precipitation and adsorption during the solution ozonizing, decrease in Mn concentration in LRW model solution reaches 94.3%, 137Cs activity decreases by 26%, and 90Sr — 15.7%, concentration of Co decreases only by 6%.


2013 ◽  
Vol 1518 ◽  
pp. 157-164
Author(s):  
A.V. Lebedeva ◽  
L.P. Sukhanov ◽  
O.A Ustinov

ABSTRACTThe report presents the results of research and development on cementation technology of liquid radioactive waste (LRW) generated in spent nuclear fuel reprocessing in Experimental Demonstration Center (EDC) at the Mountain Chemical Combine, Russian Federation.


2017 ◽  
Vol 153 ◽  
pp. 07035 ◽  
Author(s):  
Mikhail Ternovykh ◽  
Georgy Tikhomirov ◽  
Ivan Saldikov ◽  
Alexander Gerasimov

Energy ◽  
2019 ◽  
Vol 170 ◽  
pp. 978-985 ◽  
Author(s):  
R. Poškas ◽  
V. Šimonis ◽  
H. Jouhara ◽  
P. Poškas

2019 ◽  
Vol 133 ◽  
pp. 02005
Author(s):  
Markéta Camfrlová

Nuclear energy accounts for a significant part of the total energy production in the Czech Republic, which is currently facing a problem dealing with the high-level radioactive waste (HLW) and the spent nuclear fuel (SNF). Deep repository is the safest option for storage of HLW. Rock environment of the area must guarantee the stability of the deep geological repository for at least 100,000 years. The aim of the research is a long-term evaluation of the climatic changes of the hypothetical area of interest, which corresponds to the candidate sites for deep geological repository in the Czech Republic. The occurrences of endogenous and exogenous phenomena, which could affect site stability, were evaluated. Concerning exogenous processes, research focuses mainly on the assessment of climatic effects. The climate scenarios for the Central Europe were examined – global climate change, glaciation, and the depth of permafrost as well as CO2 increase.


Author(s):  
Bjo̸rn Borgaas ◽  
Ingar Amundsen ◽  
Ole Reistadt

This paper describes the cooperation and inspection arrangements for verifying the dismantlement of non-strategic Russian submarines, including waste handling, in accordance with the provisions given in the bilateral agreement between the Governments of Russia and Norway and the Norwegian Plan of Action for Nuclear Safety. The main concerns during the project implementation are nuclear safety, the individual safety of workers and the safe and secure handling of radioactive and toxic wastes. Based on data provided by the shipyard on individual exposure, one dismantlement project results in average in an effective dose for shipyard workers between 1,1 and 1,9 mSv, depending on the scope of the work for each worker. The main conclusion is that the present handling of solid radioactive waste is not optimal as such waste now is being put into the reactor compartments without the possibility for adequate control, including the retrieval for repacking or transfer to adequate storage facilities, after the reactor compartments have been placed in the long term storage facility in Saida Bay. Today there is no repository in Northwest-Russia for defence-related radioactive waste.


Author(s):  
Konstantin N. Koulikov ◽  
Rinat A. Nizamutdinov ◽  
Andrey N. Abramov ◽  
Anatoly I. Tsubanikov

Having about 200 tons of solid radioactive waste aboard, the Volodarskiy Floating Technical Base (FTB) is a potential radiation pollution source for the Murmansk region and Kola Bay, as her long-term berthing negatively affects the hull structures. Thereby, Atomflot collaborated with ANO Aspect-Konversia and JSC NIPTB Onega within the frameworks of Federal Special-purpose Program “Assurance of Nuclear and Radiation Safety for 2008 and for the period up to 2015” and developed the Volodarskiy FTB dismantling concept. In 2008 in the course of development of the Volodarskiy FTB dismantling concept the following works were carried out: 1) vessel condition survey, including SRW radiological analysis; 2) feasibility study of the Volodarskiy FTB dismantling alternatives. In this regard the following alternatives were analyzed: – formation of the package assembly in the form of vessel’s undivided hull for durable storage in the Saida long-term storage facility (LTSF); - formation of individual SRW package assemblies for durable storage in the Saida LTSF; - comprehensive recycling of all solid radioactive waste by disposal in protective containers. 3) selection and approval of the dismantling alternative. The alternative of formation of individual SRW package assemblies for durable storage in the Saida LTSF was selected by the Rosatom State Corporation. In this case the works will be performed on a step-by-step basis at the Atomflot enterprise and SRE Nerpa. The conceptual dismantling technology was developed for the selected Volodarskiy FTB dismantling option. The proceedings contain description of options, analysis procedure and proposal for further study of mentioned challenge.


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