scholarly journals Analysis of the Plasma Recycling Process of Radioactive Waste

2019 ◽  
pp. 23-29
Author(s):  
M. Semerak ◽  
S. Lys ◽  
T. Kovalenko
Keyword(s):  
Radioactive Waste ◽  
Silicon Oxide ◽  
Raw Materials ◽  
Shaft Furnace ◽  
Plasma Heating ◽  
Plasma Processing ◽  
Radioactive Wastes ◽  
Heating Source ◽  
Long Term Storage ◽  
Plasmochemical Reactor

The possibility of the plasma processing of low-level or intermediatelevel radioactive wastes in the reactor equipped with arc plasmatrons is shown. The reactor design for the plasma processing of the radioactive wastes that allows promoting the efficiency of the plasma processing of the radioactive wastes (RAW) by the increasing of the speed and the intensity of the plasma pyrolysis is proposed. The various methods for RAW preparation, dosage and supply into the plasmochemical reactor have been investigated. The waste which is supplied to the reactor can be in various aggregate states (solid, liquid or gaseous) depending on which different kinds of preparation, dosage, and supply of RAW materials to the plasmochemical reactor are used. The solid waste must be ground for increasing of the phase separation surface. The degree of grinding of the wastes depends on their further reprocessing. The reactor allows processing of the mixed-type radioactive waste, which includes both combustible and non-combustible components. The wastes can be packed or ground up. The selected technological regimes should provide temperature from 1500 °C in the melting chamber to 250 °C in the upper part in the pyrogas exit zone to prevent the flow-out of volatile compounds of a series of radionuclides and heavy metals from the furnace and to process the waste and merge slag melt without adding of fluxes. The fused slag is a basaltiform monolith, where the content of aluminum oxide reaches 28%; silicon oxide up to 56%; sodium oxide from 2.5 to 11 %. The resulting radioactive slag is extremely resistant to the chemical influence. The pyrogas produced in the shaft furnace will have a heating value of about 5 MJ/nm3. This allows, after initial heating by plasmatron, maintaining the required temperature in the combustion chamber due to the heat released during combustion of the pyrogas, when the plasma heating source is switched off, and burning the resin and soot effectively. It is proved that the plasma technology for RAW reprocessing allows a significant reduction in waste volumes and waste placement for long-term storage with the most efficient use of storage facilities.

Increasing Operational Efficiency in a Radioactive Waste Processing Plant

2009 ◽  
Author(s):  
T. W. Turner ◽  
S. N. Watson
Keyword(s):  
Radioactive Waste ◽  
Solid Waste ◽  
Management Practices ◽  
Operational Efficiency ◽  
Processing Plant ◽  
Waste Processing ◽  
Long Term Storage ◽  
Below Ground ◽  
Pass Through ◽  
Intermediate Level Radioactive Waste

The solid waste plant at Harwell in Oxfordshire, contains a purpose built facility to input, assay, visually inspect and sort remote handled intermediate level radioactive waste (RHILW). The facility includes a suite of remote handling cells, known as the head-end cells (HEC), which waste must pass through in order to be repackaged. Some newly created waste from decommissioning works on site passes through the cells, but the vast majority of waste for processing is historical waste, stored in below ground tube stores. Existing containers are not suitable for long term storage, many are already badly corroded, so the waste must be efficiently processed and repackaged in order to achieve passive safety. The Harwell site is currently being decommissioned and the land is being restored. The site is being progressively delicensed, and redeveloped as a business park, which can only be completed when all the nuclear liabilities have been removed. The recovery and processing of old waste in the solid waste plant is a key project linked to delicensing of a section of the site. Increasing the operational efficiency of the waste processing plant could shorten the time needed to clear the site and has the potential to save money for the Nuclear Decommissioning Authority (NDA). The waste processing facility was constructed in the mid 1990s, and commissioned in 1999. Since operations began, the yearly throughput of the cells has increased significantly every year. To achieve targets set out in the lifetime plan (LTP) for the site, throughput must continue to increase. The operations department has measured the overall equipment effectiveness (OEE) of the process for the last few years, and has used continuous improvement techniques to decrease the average cycle time. Philosophies from operational management practices such as ‘lean’ and ‘kaizen’ have been employed successfully to drive out losses and increase plant efficiency. This paper will describe how the solid waste plant at Harwell has continuously increased the throughput of RHILW, which should lead to significant programme savings.

Screening of Agricultural Raw Materials and Long-Term Storage Products to Identify Bacillary Contaminants

2019 ◽  
pp. 641-653
Author(s):  
Olena Danylova ◽  
Marina Serdyuk ◽  
Liudmyla Pylypenko ◽  
Victor Pelykh ◽  
Inna Lopotan ◽  
...  
Keyword(s):  
Raw Materials ◽  
Long Term Storage ◽  
Storage Products ◽  
Term Storage

scholarly journals Reduction Properties of Raw Materials for Direct Reduction Shaft Furnace

1977 ◽  
Vol 63 (14) ◽  
pp. 2269-2277
Author(s):  
Dentaro KANEKO ◽  
Yoshio KIMURA ◽  
Mamoru ONODA ◽  
Isao FUJITA
Keyword(s):  
Raw Materials ◽  
Shaft Furnace ◽  
Direct Reduction

scholarly journals Dry functional blend with fruit-berry powders for yeast dough

2019 ◽  
Vol 81 (2) ◽  
pp. 177-183
Author(s):  
A. V. Moshkin ◽  
A. T. Vasyukova ◽  
A. E. Alexeyev
Keyword(s):  
Raw Materials ◽  
Long Term Storage ◽  
Chemical Indicators ◽  
Toxicological Studies ◽  
The Russian Federation ◽  
Milk Mixture ◽  
Physical And Chemical ◽  
Term Storage ◽  
High Calorie

The basic information about functional mixtures is outlined, options for compositions and recommendations for use in baking in mass production are proposed. The characteristic of microbiological, physical and chemical indicators is given, and the results of toxicological studies of dry functional mixtures with fruit and berry powders are given. High-calorie, medium-calorie, and low-calorie composite mixtures have been developed for the centralized production of yeast dough. Dry functional mixtures can be produced according to regulatory documents: TU 9161-004-51926638-11 and TI to TU 9161-004-51926638-11. A patent of the Russian Federation No. 2602629 was obtained for dry functional mixtures with fruit and berry powders. The technological scheme for obtaining a dry functional mixture consists of the following operations: sifting, dosing of prescription components in predetermined proportions: dry egg-milk mixture in the amount of 56.2-61.6% sugar – 20.0-24.3% and salt – 14.1-17.2%. Xanthan (1.06-2.43%) or guar (4.25-5.30%) and fruit and berry powders (1.0-1.5%) are introduced as additional raw materials. Then mixing is carried out, preparation for implementation. The resulting mixture is portioned and packaged in paper bags. Fruit and berry powders were prepared from rose hips, aronia, nettle, bananas, apples and carrots. According to microbiological studies, the degree of contamination during storage during the year corresponds to SanPiN 2.3.2.1078-01, which makes it possible to produce dry functional mixtures with fruit and berry powders for long-term storage. They can be stored in a dry, well-ventilated room in compliance with sanitary rules, with a relative humidity of 65-70% and a temperature of 18-20 °C from 0 to 12 months. It was found that during storage for 12 months. in hermetically sealed paper bags, no powder quality changes were observed. Bakery products made using these mixtures can be recommended for medical, preventive and gerontological nutrition.

scholarly journals QUANTITY LOWERING OF THE FORMED INTERMEDIATE COMPOUNDS UNDER SULFOFERITE CLINKER SYNTHESIS

2016 ◽  
Vol 1 (12) ◽  
pp. 188-194
Author(s):  
Борисов ◽  
Ivan Borisov ◽  
Гребенюк ◽  
Aleksandr Grebenyuk
Keyword(s):  
Calcium Silicate ◽  
Silicon Oxide ◽  
Raw Materials

The ability of the concurrence of ferrites calcium reaction sulphatization and calcium silicate sulfate building was identified by calculating. Possible ways of the calcium silicate sulfate building reaction were determined. The ways of calcium silicate sulfate building number lowering by preparation sulfoferrite clinker out of raw materials which contain silicon oxide high quantity.

scholarly journals CO2 Utilization and Long-Term Storage in Useful Mineral Products by Carbonation of Alkaline Feedstocks

2021 ◽  
Vol 9 ◽  
Author(s):  
Renato Baciocchi ◽  
Giulia Costa
Keyword(s):  
Raw Materials ◽  
Mineral Carbonation ◽  
Carbon Utilization ◽  
Waste Streams ◽  
Long Term Storage ◽  
Current State ◽  
Critical Issues ◽  
Term Storage ◽  
Change Mitigation

Accelerated carbonation is a carbon utilization option which allows the manufacturing of useful products, employing CO2-concentrated or -diluted emission sources and waste streams such as industrial or other processing solid residues, in a circular economy perspective. If properly implemented, it may reduce the exploitation of virgin raw materials and their associated environmental footprint and permanently store CO2 in the form of Ca and/or Mg carbonates, thus effectively contributing to climate change mitigation. In this perspective article, we first report an overview of the main mineral carbonation pathways that have been developed up to now, focusing on those which were specifically designed to obtain useful products, starting from different alkaline feedstocks. Based on the current state of the art, we then discuss the main critical issues that still need to be addressed in order to improve the overall feasibility of mineral carbonation as a CCUS option, as well as research needs and opportunities.

Backfill of Radioactive Waste Disposal: Feasibility Study of Argillite/Bentonite (COx/MX80) Pellets

2021 ◽  
Author(s):  
Danai Tyri ◽  
Bui Quoc Huy Ly ◽  
François Nader ◽  
Irini Djeran-Maigre ◽  
Jean-Claude Robinet ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Mechanical Response ◽  
Raw Materials ◽  
Radioactive Waste Disposal ◽  
Maximum Diameter ◽  
Optimal Conditions ◽  
Swelling Potential ◽  
Deep Geological Disposal ◽  
In The Beginning ◽  
Influential Parameters

Abstract A pelletized solution composed of COx argillite and MX80 bentonite is examined as backfill for the deep geological disposal of radioactive waste (Cigeo project). The implementation is studied in terms of installation and hydration conditions as well as their influence on the hydro-mechanical behavior of the mixture. In the beginning, the optimum grain size distribution (GSD) of pellets assembly is determined to minimize initial voids. A series of DEM simulations on ternary samples made of spheres is carried out, investigating the optimal conditions in terms of sizes and proportions. Density maximization occurs when maximum diameter is the dominant size, while minimum and medium diameters are following. As optimum GSD, sizes of 16 mm, 10 mm and 4 mm in 60%, 10% and 30% respectively are chosen. The pelletization of the selected sizes is optimized using an adapted tablet machine to carry out the pellet fabrication. A detailed analysis of influential parameters related to the machine accessories and the inserted raw materials is presented. After modifications, quasi-spherical pellets presenting density of at least 1.95 Mg/m3 are produced. COx/MX80 pellets hydro-mechanical response is indirectly assessed by studying the swelling potential of COx/MX80 powdered mixtures at equivalent emplaced densities. The influence of density, stress and MX80 content on swelling is obtained.

Iron-Enriched Basalt and its Application to Three-Mile Island Radioactive Waste Disposal

1981 ◽  
Vol 6 ◽  
Author(s):  
P. V. Kelsey ◽  
R. P. Schuman ◽  
J. M. Welch ◽  
D. E. Owen ◽  
J. E. Flinn
Keyword(s):  
Radioactive Waste ◽  
Waste Disposal ◽  
Deionized Water ◽  
Radioactive Wastes ◽  
Radioactive Waste Disposal ◽  
Leaching Tests ◽  
Type 304

ABSTRACTDemonstration tests were performed on iron-enriched basalt (IEB), a dissolution and immobilization medium for TMI radioactive wastes. Zeolite of the type used for cesium and strontium decontamination of TMI containment water was mixed with 20 wt% additives and melted at 1500°C to form IEB. Cesium volatility from the IEB melts was low. Leaching tests in 90°C deionized water showed leach rates of 6 μg/cm2 d for both cesium and strontium. IEB melts were used to dissolve Type 304 SS pellets and UO2 pellets clad with zircaloy in order to simulate immobilization of TMI core debris. Bubbling air through the melts greatly enhanced the dissolution of these components.

Investigation of Urtite as an Analog of Waste Slag from a Plasma Shaff Furnace

1995 ◽  
Vol 412 ◽  
Author(s):  
S. A. Dmitriev ◽  
S. V. Stefanovsky
Keyword(s):  
Radioactive Waste ◽  
Electron Probe ◽  
Nepheline Syenite ◽  
Shaft Furnace ◽  
Alkali Feldspar ◽  
Chemical Compositions ◽  
Natural Analog ◽  
First Approximation ◽  
Geochemical Investigation

abstractMineralogical-geochemical investigation of a sample of nepheline syenite (urtite) as a natural analog of final radioactive waste form has been performed. The specimen of urtite consists of nepheline, alkali feldspar, pyroxene, sphene, apatite and minor magnetite and amphibole. As a first approximation, urtite simulates the mineral composition of waste slag produced in a plasma shaft furnace at SIA “Radon”. Determination of chemical compositions of the minerals by electron-probe microanalysis has shown that the main phases that hosted radionuclides and their geochemical analogs are as follows: nepheline (Rb and probably Cs), feldspar (Ba), sphene (Zr, Nb, REE, and actinides) and apatite (Sr, REE, and actinides).

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