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At least 559 records · Page 31

Area V: Waste Management and Subsurface Science (FY23 Q2)

The objective of Topic Area V is to evaluate the feasibility and safety of an intermediate-depth borehole for disposal of IAEC nuclear waste. The IAEC nuclear waste is currently stored in above ground and/or in near-surface facilities that provide short-term radiological worker safety but do not provide long-term, full security and safeguards protection for the nuclear material. Disposal of the IAEC nuclear waste several hundred meters below the surface in a sealed borehole would provide long-term security and safeguards due to its depth underground, as well as long-term radiological safety, due to its isolation in a stable geological formation.

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Waste management technology development and demonstration programs at Brookhaven National Laboratory

Two thermoplastic processes for improved treatment of radioactive, hazardous, and mixed wastes were developed from bench scale through technology demonstration: polyethylene encapsulation and modified sulfur cement encapsulation. The steps required to bring technologies from the research and development stage through full scale implementation are described. Both systems result in durable waste forms that meet current Nuclear Regulatory Commission and Environmental Protection Agency regulatory criteria and provide significant improvements over conventional solidification systems such as hydraulic cement. For example, the polyethylene process can encapsulate up to 70 wt pct. nitrate salt, compared with a maximum of about 20 wt pct. for the best hydraulic cement formulation. Modified sulfur cement waste forms containing as much as 43 wt pct. incinerator fly ash were formulated, whereas the maximum quantity of this waste in hydraulic cement is 16 wt pct.

Kalb, Paul D.↗

Understanding Radionuclide Interactions with Cementitious Materials for Radioactive Waste Management - 18298

In the UK, ILW is currently managed using cementitious encapsulation in Portland cement (PC)-based grouts. The long-term behaviour of radionuclides in ILW cementitious waste-forms under varying local conditions of extended interim storage and geological disposal is not well understood and the behaviour of cement minerals in the retention of various radionuclides is poorly constrained. This work focuses on the Ca-Si-[Al,Mg,S] mineral system and how this may evolve with the introduction of radionuclides into the system. Here, we discuss the experimental program aimed at underpinning the uptake and retention mechanisms of a range of key radionuclides (U, Tc, Ce/Pu), with selected cement phases: calcium-silicate-hydrate (C-S-H), hydrotalcite (Mg{sub 6}Al{sub 2}CO{sub 3}(OH)16.4H{sub 2}O) and ettringite (Ca{sub 6}(Al{sub 2}O{sub 6})(SO{sub 4}){sub 3}.32H{sub 2}O). Described here is the syntheses of C-S-H and radionuclide incorporation experiments performed on this phase. Further to this, thermodynamic geochemical modelling has been adopted to explore the Ca-Si-U mineral system, aimed at identifying the mineral phases likely to form on contact of C-S-H phases with aqueous uranium, as a function of pH. (authors)

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RCRA Permit for a Hazardous Waste Management Facility Permit Number NEV HW0101, Annual Summary/Waste Minimization Report, Calendar Year 2015, Nevada National Security Site, Nevada

This report summarizes the EPA identification number of each generator from which the Permittee received a waste stream, a description and quantity of each waste stream in tons and cubic feet received at the facility, the method of treatment, storage, and/or disposal for each waste stream, a description of the waste minimization efforts undertaken, a description of the changes in volume and toxicity of waste actually received, any unusual occurrences, and the results of tank integrity assessments. This Annual Summary/Waste Minimization Report is prepared in accordance with Section 2.13.5 of Permit Number NEV HW0101.

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The Use of Legally-Imposed and Locally-Negotiated Incentive Approaches in the Siting of Nuclear Waste Management Facilities: Comparing Stakeholders' Views in the Czech Republic, Poland and Slovenia - 13534

The purpose here is to contribute to the discussion surrounding the use of community benefits (also known as added value) in radioactive waste facility siting programmes. These are becoming more widely used following a series of programme failures around the world, due in the main to a lack of local involvement. A number of different models for the use of community benefits and why they may or may not assist a siting process exist in the literature, based on either a voluntary market approach or one involving coercion by a state authority or developer. Review of real-life examples suggests that two main approaches to the use of benefits exist, a 'legally-mandated' approach where details are laid down in legislation, and a 'locally-negotiated' approach where the details are agreed by the parties through discussions. As part of the European Commission supported IPPA project (Implementing Public Participation Approaches in Radioactive Waste Disposal), stakeholder groups in three participant countries, the Czech Republic, Poland and Slovenia, all of which currently utilise the 'legally-mandated' approach to the provision of community benefits, were invited to respond to a series of questions designed to explore their attitudes and thoughts about the two approaches and related issues such as trust in the institutions and the legal framework. Some initial results and conclusions are presented, although this work is continuing and will be reported at the end of the IPPA project in 2013. (authors)

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RCRA Permit for a Hazardous Waste Management Facility Permit Number NEV HW0101 Annual Summary/Waste Minimization Report Calendar Year 2012, Nevada National Security Site, Nevada

This report summarizes the U.S. Environmental Protection Agency (EPA) identification number of each generator from which the Permittee received a waste stream, a description and quantity of each waste stream in tons and cubic feet received at the facility, the method of treatment, storage, and/or disposal for each waste stream, a description of the waste minimization efforts undertaken, a description of the changes in volume and toxicity of waste actually received, any unusual occurrences, and the results of tank integrity assessments. This Annual Summary/Waste Minimization Report is prepared in accordance with Section 2.13.3 of Permit Number NEV HW0101, issued 10/17/10.

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Wet-oxidation waste management system for CELSS

A wet oxidation system will be useful in the Closed Ecological Life Support System (CELSS) as a facility to treat organic wastes and to redistribute inorganic compounds and elements. However at rather higher temperatures needed in this reaction, for instance, at 260 deg C, only 80% of organic in a raw material can be oxidized, and 20% of it will remain in the liquid mainly as acetic acid, which is virtually noncombustible. Furthermore, nitrogen is transformed to ammonium ions which normally cannot be absorbed by plants. To resolve these problems, it becomes necessary to use catalysts. Noble metals such as Ru, Rh and so on have proved to be partially effective as these catalysts. That is, oxidation does not occur completely, and the unexpected denitrification, instead of the expected nitrification, occurs. So, it is essential to develop the catalysts which are able to realize the complete oxidation and the nitrification.

Takahashi, Y.↗

Plasma reactor waste management systems

The University of North Dakota is developing a plasma reactor system for use in closed-loop processing that includes biological, materials, manufacturing, and waste processing. Direct-current, high-frequency, or microwave discharges will be used to produce plasmas for the treatment of materials. The plasma reactors offer several advantages over other systems, including low operating temperatures, low operating pressures, mechanical simplicity, and relatively safe operation. Human fecal material, sunflowers, oats, soybeans, and plastic were oxidized in a batch plasma reactor. Over 98 percent of the organic material was converted to gaseous products. The solids were then analyzed and a large amount of water and acid-soluble materials were detected. These materials could possibly be used as nutrients for biological systems.

Ness, Robert O., Jr.↗

Occupational hygiene in terms of volatile organic compounds (VOCs) and bioaerosols at two solid waste management plants in Finland

Highlights: ► Odorous VOCs: acetic acid, 2,3-butanedione, ethyl acetate, alpha-pinene and limonene. ► VOC concentrations did not exceed occupational exposure limit concentrations. ► 2,3-Butanedione as the health effecting compound is discussed. ► Endotoxin concentrations may cause health problems in waste treatment. - Abstract: Factors affecting occupational hygiene were measured at the solid waste transferring plant at Hyvinkää and at the optic separation plant in Hämeenlinna. Measurements consisted of volatile organic compounds (VOCs) and bioaerosols including microbes, dust and endotoxins. The most abundant compounds in both of the plants were aliphatic and aromatic hydrocarbons, esters of carboxylic acids, ketones and terpenes. In terms of odour generation, the most important emissions were acetic acid, 2,3-butanedione, ethyl acetate, alpha-pinene and limonene due to their low threshold odour concentrations. At the optic waste separation plant, limonene occurred at the highest concentration of all single compounds of identified VOCs. The concentration of any single volatile organic compound did not exceed the occupational exposure limit (OEL) concentration. However, 2,3-butanedione as a health risk compound is discussed based on recent scientific findings linking it to lung disease. Microbe and dust concentrations were low at the waste transferring plant. Only endotoxin concentrations may cause health problems; the average concentration inside the plant was 425 EU/m{sup 3} which clearly exceeded the threshold value of 90 EU/m{sup 3}. In the wheel loader cabin the endotoxin concentrations were below 1 EU/m{sup 3}. High microbial and endotoxin concentrations were measured in the processing hall at the optic waste separation plant. The average concentration of endotoxins was found to be 10,980 EU/m{sup 3}, a concentration which may cause health risks. Concentrations of viable fungi were quite high in few measurements in the control room. The most problematic factor was endotoxins whose average measured concentrations was 4853 EU/m{sup 3}.

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