Stabilization of Underground Solvent Storage Tanks

Author(s):  
Timothy R. Smail ◽  
Annamarie M. Herb ◽  
Monica C. Hall

The Old Solvent Tanks (OST), located at the Savannah River Site (SRS) Old Radioactive Waster Burial Ground (ORWBG), are comprised of 22 underground storage tanks that were used to store spent radioactive solvent and aqueous wastes generated from the plutonium-uranium extraction (PUREX) process. The OSTs were installed at various dates between 1955 and 1968 and used to store the spent solvents until 1974. The spent solvents stored in the OSTs were transferred out from 1976 through 1981 leaving only residual liquids and sludges that could not be pumped out. Final remediation goals for the ORWBG include an overlying infiltration control system. If the tanks were to structurally fail, they would collapse causing potential for onsite worker exposure and release of tank contents to the environment. Therefore, as an interim action, methods for stabilizing the tanks were evaluated. The preferred remedial action was “Grouting of the Tank Wastes In-situ.” The primary function of the grout is to provide structural stability of the tanks by filling void space with material that prevents tank collapse. Incidental to any mixing that may occur, residual material in the tanks will be incorporated into the grouting mixture. The incidental grouting will ultimately improve environmental protection by rendering the residual material immobile. To accomplish this task, the SRS Environmental Restoration Division (ERD) teamed with the Savannah River Technology Center (SRTC) to determine a remedial design strategy and to translate this strategy into a construction specification and drawings for implementation. The OST remedial design strategy contained the following key aspects for performance requirements and acceptance criteria: • Grout mix; • Tank atmosphere testing; • Grout delivery system and camera monitoring system; • Off-Gas HEPA filter system and environmental monitoring; • OST Sealing and labeling. From November 2001 through February 2003 all 22 Old Solvent Tanks were successfully stabilized. This paper will discuss the systems designed to perform and monitor the grouting operation, the grouting process, and the radiological controls and wastes associated with grouting the Old Solvent Tanks.

Author(s):  
Chunlang Gao ◽  
Chunqiang Zhuang ◽  
Yuanli Li ◽  
Heyang Qi ◽  
Ge Chen ◽  
...  

In this study, we employed in-situ liquid cell transmission electron microscopy (LC-TEM) to carry out the new design strategy of precisely regulating the microstructure of large-sized cocatalysts for highly efficient...


2021 ◽  
Vol 22 (9) ◽  
pp. 4732
Author(s):  
Vincenza Ylenia Cusenza ◽  
Alessandra Bisagni ◽  
Monia Rinaldini ◽  
Chiara Cattani ◽  
Raffaele Frazzi

The cytogenetic and molecular assessment of deletions, amplifications and rearrangements are key aspects in the diagnosis and therapy of cancer. Not only the initial evaluation and classification of the disease, but also the follow-up of the tumor rely on these laboratory approaches. The therapeutic choice can be guided by the results of the laboratory testing. Genetic deletions and/or amplifications directly affect the susceptibility or the resistance to specific therapies. In an era of personalized medicine, the correct and reliable molecular characterization of the disease, also during the therapeutic path, acquires a pivotal role. Molecular assays like multiplex ligation-dependent probe amplification and droplet digital PCR represent exceptional tools for a sensitive and reliable detection of genetic alterations and deserve a role in molecular oncology. In this manuscript we provide a technical comparison of these two approaches with the golden standard represented by fluorescence in situ hybridization. We also describe some relevant targets currently evaluated with these techniques in solid and hematologic tumors.


2021 ◽  
Author(s):  
Olivier Duriez ◽  
Jovan Andevski ◽  
Christopher G. R. Bowden ◽  
Alvaro Camiña-Cardenal ◽  
Hans Frey ◽  
...  

ABSTRACT Although vulture feeding stations are a widely used tool for vulture conservation in many regions worldwide, there has been some confusion about their functions and this is reflected in the range of terminology used. The origin of food supply at provisioning sites (both for in situ and ex situ situations) and the goals of feeding station managers (ranging from purely conservation of vultures to the necessity for carcass disposal) are two key aspects that are often neglected. We review the definitions and nomenclature for the provision of predictable anthropogenic food for vultures and vultures' role in sanitation in the landscape. We propose that “supplementary feeding stations for vultures” (SFSV) defines a particular case and this term should only be applied when a station has vulture conservation goals and a food supply coming from outside of the landscape (ex situ). We introduce the term “recycling station with vultures” (RSV) for cases when the goal is the elimination of carcasses and the food is sourced in situ (natural, NRSV) or ex situ (supplementary food, SRSV). This clarification of goals and terminology for feeding stations worldwide could have important consequences for the understanding and assessment of vulture conservation and management actions, among researchers and conservationists and also importantly among stakeholders and wider society.


2021 ◽  
Author(s):  
Raj Lahoti

Abstract Getting correct estimates for Volatile Organic Compounds (VOCs) and greenhouse gases (GHGs) from water storage tanks is not only important for maintaining emission compliance for state and national regulatory authorities, but also crucial in designing the capital-intensive systems for economic use of methane and other Natural Gas Liquid (NGL) gasses. This paper highlights the significance of gas liberated from produced water tanks in the fields. The paper presents a laboratory method to estimate such emissions from produced-water storage tanks by virtue of the in-situ water getting depressurized and releasing VOCs, and other emission gasses such as Hydrogen Sulfide (H2S) and Carbon Dioxide (CO2). Further, the paper provides qualitative and quantitative assessment of the gas liberated from produced-water by analyzing the gas liberated from produced-water from gas-condensate reservoir wells from the Marcellus region.


2017 ◽  
Vol 17 (2) ◽  
pp. 185-196
Author(s):  
Mario Scalas ◽  
Palmalisa Marra ◽  
Luca Tedesco ◽  
Raffaele Quarta ◽  
Emanuele Cantoro ◽  
...  

Abstract. This article describes the architecture of sea situational awareness (SSA) platform, a major asset within TESSA, an industrial research project funded by the Italian Ministry of Education and Research. The main aim of the platform is to collect, transform and provide forecast and observational data as information suitable for delivery across a variety of channels, like web and mobile; specifically, the ability to produce and provide forecast information suitable for creating SSA-enabled applications has been a critical driving factor when designing and evolving the whole architecture. Thus, starting from functional and performance requirements, the platform architecture is described in terms of its main building blocks and flows among them: front-end components that support end-user applications and map and data analysis components that allow for serving maps and querying data. Focus is directed to key aspects and decisions about the main issues faced, like interoperability, scalability, efficiency and adaptability, but it also considers insights about future works in this and similarly related subjects. Some analysis results are also provided in order to better characterize critical issues and related solutions.


2021 ◽  
Author(s):  
Evin Magner ◽  
Pamela Sandoval-Sanchez ◽  
Peter F Hitchcock ◽  
Scott M Taylor

Abstract In mammals, photoreceptor loss causes permanent blindness, but in zebrafish (Danio rerio), Müller glia function as intrinsic stem cells, producing progenitor cells that regenerate photoreceptors and restore vision. MicroRNAs (miRNAs) critically regulate neurogenesis in the brain and retina, but the roles of miRNAs in injury-induced neuronal regeneration are largely unknown. The miRNA miR-18a regulates photoreceptor differentiation in the embryonic retina. The purpose of the current study was to determine the function of miR-18a during injury-induced photoreceptor regeneration. RT-qPCR, in-situ hybridization (ISH) and immunohistochemistry (IHC) showed that miR-18a expression increases throughout the retina by 1-day post-injury (dpi) and continues to increase through 5 dpi. Bromodeoxyuridine (BrdU) labeling showed that at 7 and 10 dpi, when regenerated photoreceptors are normally differentiating, there are more proliferating Müller glia-derived progenitors in homozygous miR-18a mutant (miR-18ami5012) retinas compared with wild type (WT), indicating that miR-18a negatively regulates injury-induced proliferation. At 7 and 10 dpi, miR-18ami5012 retinas have fewer mature photoreceptors than WT, but there is no difference at 14 dpi, revealing that photoreceptor regeneration is delayed. BrdU labeling showed that the excess progenitors in miR-18ami5012 retinas migrate to other retinal layers besides the photoreceptor layer. Inflammation is critical for photoreceptor regeneration and RT-qPCR showed that, in the absence of miR-18a, inflammation is prolonged. Suppressing inflammation with dexamethasone rescues the miR-18ami5012 phenotype. Together, these data show that during injury-induced photoreceptor regeneration, miR-18a regulates proliferation and photoreceptor regeneration by regulating key aspects of the inflammatory response during photoreceptor regeneration in zebrafish.


2008 ◽  
Vol 1124 ◽  
Author(s):  
Gerald Hans Nieder-Westermann ◽  
Robert H. Spencer ◽  
Robert W Andrews ◽  
Neil Brown

AbstractThe Yucca Mountain repository combines multiple barriers, both natural and engineered, which work both individually and collectively to limit the movement of water and the potential release and movement of radionuclides to the accessible environment. Engineered structures, systems and components (SSCs) are designed to function in the natural environment utilizing materials chosen to perform their intended functions in order to meet the postclosure performance objectives. Similarly, the features of the natural environment are expected to respond to the presence of the repository through geomechanical, hydrogeologic and geochemical changes. At Yucca Mountain, specific features, both engineered and natural have been identified as requiring design control during repository construction and operations. The integration between design and postclosure safety analysis is facilitated using design control parameters. The term “design control parameters” includes functions and performance requirements allocated to SSCs through the design process, as well as the attributes of SSCs that are developed during design (e.g., dimensions; weights; materials; fabrication and quality-control processes; and operating conditions). These control parameters provide an interface between the design and the analyzed postclosure safety bases, which needs to be maintained through the licensing process. Maintenance of the design is controlled through configuration management and procedural safety controls. The design control parameters serve three key purposes. First, they identify key aspects of the design that serve as the design bases for the designers of the SSCs of the facility. Second, they provide a useful input to the analyses of relevant postclosure features, events and processes (FEPs) and are used to either exclude FEPs from the postclosure safety analysis or as an input to models of included FEPs in the safety analysis. Finally, they provide important controlled interface constraints between the design and safety analyses organizations that are amenable to configuration management. Several examples of such design controls will be presented in this briefing. The first type of design controls relates to the location of the underground facility, including standoffs from faults and the ground surface. The second type of design controls relates to the configuration of the engineered features including the spacing of emplacement driftsand drip shield dimensions and characteristics. A third type of design controls relates to constraints on handling, loading and emplacing waste forms in canisters and waste packages in the emplacement drifts.


2011 ◽  
Vol 466 ◽  
pp. 131-139 ◽  
Author(s):  
Deon Kruger ◽  
Michael van der Westhuizen

Certain construction situations call for the use of ultra-lightweight concrete materials. The properties of such materials allow for the utilisation of concrete in weight critical applications, for example precast elements, roofing panels, flooring and cladding of structures. The weight saving benefits of lightweight concrete are evident, yet a trade-off in the strength and durability characteristics of the concrete are made. This paper sets out to develop an ultra-lightweight thin filmed polymer modified concrete material for such applications. This material may incorporate specialised aggregates and admixtures to meet performance requirements but the effects of these on the performance of the lightweight concrete are to be carefully evaluated. This paper presents some of the results obtained by means of laboratory testing as well in-situ testing. As part of the in-situ testing, the paper also reports on the practical evaluation of the ultra-lightweight material characteristics performed through the construction of a light weight concrete racing canoe. This allowed for the evaluation of the material performance characteristics and the establishment of acceptable work and application methods when constructing with this material.


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