scholarly journals Considerations for Grout Formulations for Facility Closures Using In Situ Strategies

2010 ◽  
Author(s):  
Michael J. Serrato ◽  
Christine A. Langton ◽  
John B. Gladden ◽  
John T. Long ◽  
John K. Blankenship ◽  
...  
Keyword(s):  
South Carolina ◽  
Heat Generation ◽  
Structural Integrity ◽  
Hydrogen Generation ◽  
High Heat ◽  
Heat Of Hydration ◽  
Department Of Energy ◽  
Large Size

The U.S. Department of Energy (DOE) is conducting in situ closures (entombment) at a large number of facilities throughout the complex. Among the largest closure actions currently underway are the closures of the P and R Reactors at the Savannah River Site (SRS), near Aiken, South Carolina. In these facilities, subgrade open spaces are being stabilized with grout; this ensures the long term structural integrity of the facilities and permanently immobilizes and isolates residual contamination. The large size and structural complexity of these facilities present a wide variety of challenges for the identification and selection of appropriate fill materials. Considerations for grout formulations must account for flowability, long term stability, set times, heat generation and interactions with materials within the structure. The large size and configuration of the facility necessitates that grout must be pumped from the exterior to the spaces to be filled, which requires that the material must retain a high degree of flowability to move through piping without clogging while achieving the required leveling properties at the pour site. Set times and curing properties must be controlled to meet operations schedules, while not generating sufficient heat to compromise the properties of the fill material. The properties of residual materials can result in additional requirements for grout formulations. If significant quantities of aluminum are present in the facility, common formulations of highly alkaline grouts may not be appropriate because of the potential for hydrogen generation with the resultant risks. SRS is developing specialized inorganic grout formulations that are designed to address this issue. One circum-neutral chemical grout formulation identified for initial consideration did not possess the proper chemical characteristics, having exceptionally short set times and high heat of hydration. Research efforts are directed toward developing grout formulations that can meet operational requirements for chemical compatibility, extended set times and reduced heat generation.

Global Assessment System for Structural Safety in Large Size Storage Tanks

2004 ◽  
Author(s):  
Shinichi Kaita ◽  
Toshikazu Shibasaki ◽  
Takayasu Tahara
Keyword(s):  
Crude Oil ◽  
Global Assessment ◽  
Structural Integrity ◽  
Storage System ◽  
Assessment System ◽  
Structural Safety ◽  
Risk Level ◽  
Storage Tanks ◽  
Large Size

Considering long term stable supply of oil fuel, the world largest long-term storage system of crude oil has been installed in Japan. In order to ensure safety of large size above ground storage tanks, global assessment system for structural integrity of tank considering risk level and shut down inspection interval has been developed on Risk Based Inspection, RBI and Fitness-For-Service, FFS for storage tanks of crude oil for national security reserve.

Thermal Analysis of Drum Type Radioactive Material (RAM) Packaging Arrays in Storage

2009 ◽  
Author(s):  
Narendra K. Gupta
Keyword(s):  
Structural Integrity ◽  
Operating Conditions ◽  
Department Of Energy ◽  
Radioactive Material ◽  
Fissile Material ◽  
Long Term Storage ◽  
Design Requirements ◽  
The Impact ◽  
Term Storage

Drum type packages are routinely used to transport radioactive material (RAM) in the U.S. Department of Energy (DOE) complex. These packages are designed to meet the federal regulations described in 10 CFR 71. In recent years, there has been a greater need to use these packagings to store the excess fissile material, especially plutonium for long term storage. While the design requirements for safe transportation of these packagings are well defined, the requirements for safe long term storage are not well established. Since the RAM contents in the packagings produce decay heat, it is important that they are stored carefully to prevent overheating of the containment vessel (CV) seals to prevent any leakage and the impact limiter to maintain the package structural integrity. This paper analyzes different storage arrays for a typical 9977 packaging for thermal considerations and makes recommendations for their safe storage under normal operating conditions.

Sequestration and retention of uranium(VI) in the presence of hydroxylapatite under dynamic geochemical conditions

2008 ◽  
Vol 5 (1) ◽  
pp. 40 ◽  
Author(s):  
Dawn M. Wellman ◽  
Julia N. Glovack ◽  
Kent Parker ◽  
Emily L. Richards ◽  
Eric M. Pierce
Keyword(s):  
Heavy Metals ◽  
Department Of Energy ◽  
Geochemical Conditions ◽  
Term Retention ◽  
Remediation Strategies ◽  
The Common ◽  
Long Term Retention ◽  
Complexation Reactions

Environmental context. Contamination of surface and subsurface geologic media by heavy metals and radionuclides is a significant problem within the United State Department of Energy complex as a result of past nuclear operations. Numerous phosphate-based remediation strategies have been proposed to introduce hydroxylapatite directly or indirectly (i.e. through in situ precipitation) into subsurface regimes to act as an efficient sorbent for sequestration of metals and radionuclides such as uranium. Results presented here illustrate the importance of variable geochemical conditions on the mechanism of sequestration and long-term retention of uranium in the presence of hydroxylapatite. Abstract. Numerous solid- and aqueous-phase phosphate-based technologies for remediating heavy metals and radionuclides have the common premise of sequestration by hydroxylapatite. Complexation reactions and hydrolysis generally preclude actinides from incorporation into intracrystalline sites; rather, surface sorption and precipitation are significant mechanisms for the sequestration of actinides. The effect of pH, aqueous speciation, and the availability of reactive surface sites on minerals such as hydroxylapatite have a significant impact on the mechanism and degree of sequestration and retention of variably charged contaminants such as uranium. Yet, little attention has been given to the sequestration and retention of uranium by hydroxylapatite under dynamic geochemical conditions that may be encountered during remediation activities. We present the results of an investigation evaluating the removal of uranium by hydroxylapatite in systems near equilibrium with respect to hydroxylapatite, and the effect of dynamic aqueous geochemical conditions, such as those encountered during and subsequent to remediation activities, on the retention of uranium. Results presented here support previous investigations demonstrating the efficiency of hydroxylapatite for sequestration of uranium and illustrate the importance of geochemical conditions, including changes to surface properties and aqueous speciation, on the sequestration and retention of uranium.

Design Development and Testing of a Regenerative Rechargeable Solar Stove System

2008 ◽  
Author(s):  
Abera Melesse Ayalneh ◽  
A. Venkata Ramayya
Keyword(s):  
Heat Generation ◽  
Structural Integrity ◽  
Experimental Testing ◽  
Water Injection ◽  
Design Development ◽  
User Friendliness ◽  
Standard Family ◽  
Reversible Chemical Reaction ◽  
Capacity Cost

This paper deals with the development of a solar stove system that synthesizes the concepts of a reversible chemical reaction using CaO and water for heat generation, with that of the concentrated solar radiation for regeneration. A solar stove to take care of the needs of a standard family and which can be used at any time of the day has been designed, fabricated and used for experimental testing. A paraboloid solar concentrator has been conceived, designed and built to be used as a community facility in the neighborhood of the family for the regeneration of CaO from Ca(OH)2. Different aspects encompassing heat transfer, reaction kinetics, water injection along with structural integrity and safety have been given due consideration as also the implementation technicalities with regard to capacity, cost, user friendliness, efficiency, and adaptation of locally available materials etc. These and the experimental test results of the heat generation part of the stove system are presented and discussed. This stove system has the innate potential to endear itself to the end user and upon completion of the testing of the regeneration part can turn out to be that long term solution, one is looking for.

Identification of Possible High Integrity Containers for Low-Level Nuclear Waste Disposal

1981 ◽  
Vol 6 ◽  
Author(s):  
Jeffrey D. Williams
Keyword(s):  
South Carolina ◽  
Structural Integrity ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Economic Factors ◽  
Burial Site ◽  
Low Level ◽  
High Integrity ◽  
Low Level Radioactive Waste ◽  
Selection Of

ABSTRACTIncreased concern by the State of South Carolina over the condition and capacity of the low-level radioactive waste burial site at Barnwell has prompted them to promulgate new regulations on waste burial containers. As of September 30, 1981, ion exchange resin and filter media waste with an activity of 1 μCi/cc or greater and with isotopes with halflives greater than five years disposed at Barnwell shall be solidified or confined in a “high integrity container”. The materials and designs of these containers are required to provide waste isolation from the environment for a period of 300 years and provide the structural integrity specified in 49 CFR 173.398(b). HITTMAN has been active in the design and development of containers suitable for this purpose with this paper detailing the analyses involved. Material selections were limited to stainless steel, fiberglass, and polyethylenes. Structural concerns focused on overpressure requirements, drop-testing requirements, and lifting capabilities. With a lifetime dose of up to 108 rads, the possibilities of radiation damage were considered. Preliminary selection of polyethylene was based on satisfactory resolution of these issues and economic factors.

Modern Possibilities of Organ-Preserving Treatment in Children with Intraocular Retinoblastoma

2018 ◽  
Vol 5 (3) ◽  
pp. 175-187 ◽  
Author(s):  
O. V. Gorovtsova ◽  
T. L. Ushakova ◽  
V. G. Polyakov
Keyword(s):  
Drug Delivery ◽  
Survival Rate ◽  
Cancer Therapy ◽  
Neoadjuvant Chemotherapy ◽  
Patient Survival ◽  
Focal Therapy ◽  
Local Drug Delivery ◽  
Large Size ◽  
Intraocular Retinoblastoma

Retinoblastoma is one of highly curable diseases; today the total 5-year survival rate in patients with retinoblastoma exceeds 95%. The article summarizes the current world experience on treatment of patients with intraocular retinoblastoma. The treating skills of intraocular malignant tumor in children are a balance between the patient’s life and the preservation of an eye and its visual functions. The complex and challenging task is the treatment of common intraocular retinoblastoma groups «C», «D», «E» when the large size or localization of the tumor does not allow performing the local (focal) destruction of the tumor. As a rule, in such cases neoadjuvant chemotherapy (CT) is performed at the first stage in order to reduce the size of the tumor for further focal therapy. However, the analysed data on the effectiveness of neoadjuvant CT in combination with focal or radiotherapy demonstrated the limited possibilities of the proposed therapy. Local drug delivery in cancer therapy became a real breakthrough in the organ-preserving treatment of children with large intraocular retinoblastoma. The most widely used current methods of local drug delivery are intravitreal (IVitC) and selective intra-arterial chemotherapy (SIAC) as monotherapy or in combination with neoadjuvant CT and focal therapy which significantly increased the percentage of preserved eyes without radiotherapy administration or damage to the patient survival. The review discusses the different IVitC and SIAC techniques, chemotherapy schemes, dosages of chemotherapy, immediate and long-term complications of treatment.

Recognition of Family Caregivers in Managed Long-Term Services and Supports: South Carolina State Summary

2020 ◽  
Author(s):  
Jessica Kasten ◽  
Elizabeth Lewis ◽  
Sari Lelchook ◽  
Lynn Feinberg ◽  
Edem Hado
Keyword(s):  
South Carolina ◽  
Family Caregivers ◽  
Services And Supports

Individual differences in white and grey matter structure associated with verbal habits of thought

2019 ◽  
Author(s):  
Justin C. Hayes ◽  
Katherine L Alfred ◽  
Rachel Pizzie ◽  
Joshua S. Cetron ◽  
David J. M. Kraemer
Keyword(s):  
Individual Differences ◽  
White Matter ◽  
Cognitive Processing ◽  
Grey Matter ◽  
Structural Changes ◽  
Structural Integrity ◽  
Diffusion Tensor ◽  
Self Report ◽  
White Matter Tracts

Modality specific encoding habits account for a significant portion of individual differences reflected in functional activation during cognitive processing. Yet, little is known about how these habits of thought influence long-term structural changes in the brain. Traditionally, habits of thought have been assessed using self-report questionnaires such as the visualizer-verbalizer questionnaire. Here, rather than relying on subjective reports, we measured habits of thought using a novel behavioral task assessing attentional biases toward picture and word stimuli. Hypothesizing that verbal habits of thought are reflected in the structural integrity of white matter tracts and cortical regions of interest, we used diffusion tensor imaging and volumetric analyses to assess this prediction. Using a whole-brain approach, we show that word bias is associated with increased volume in several bilateral language regions, in both white and grey matter parcels. Additionally, connectivity within white matter tracts within an a priori speech production network increased as a function of word bias. These results demonstrate long-term structural and morphological differences associated with verbal habits of thought.

scholarly journals Contributions to Management Strategies in the NE Atlantic Regarding the Life History and Population Structure of a Key Deep-Sea Fish (Mora moro)

Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 522
Author(s):  
Régis Santos ◽  
Wendell Medeiros-Leal ◽  
Osman Crespo ◽  
Ana Novoa-Pabon ◽  
Mário Pinho
Keyword(s):  
Population Structure ◽  
Life History ◽  
Deep Sea ◽  
Management Strategies ◽  
Size Composition ◽  
Large Size ◽  
The Common ◽  
Fishing Impacts ◽  
Sea Fish

With the commercial fishery expansion to deeper waters, some vulnerable deep-sea species have been increasingly captured. To reduce the fishing impacts on these species, exploitation and management must be based on detailed and precise information about their biology. The common mora Mora moro has become the main deep-sea species caught by longliners in the Northeast Atlantic at depths between 600 and 1200 m. In the Azores, landings have more than doubled from the early 2000s to recent years. Despite its growing importance, its life history and population structure are poorly understood, and the current stock status has not been assessed. To better determine its distribution, biology, and long-term changes in abundance and size composition, this study analyzed a fishery-dependent and survey time series from the Azores. M. moro was found on mud and rock bottoms at depths below 300 m. A larger–deeper trend was observed, and females were larger and more abundant than males. The reproductive season took place from August to February. Abundance indices and mean sizes in the catch were marked by changes in fishing fleet operational behavior. M. moro is considered vulnerable to overfishing because it exhibits a long life span, a large size, slow growth, and a low natural mortality.

In Situ Activated Co3–xNixO4 as a Highly Active and Ultrastable Electrocatalyst for Hydrogen Generation

ACS Catalysis ◽  
2021 ◽  
pp. 8174-8182
Author(s):  
Kailu Guo ◽  
Yantao Wang ◽  
Junfeng Huang ◽  
Min Lu ◽  
Hua Li ◽  
...  
Keyword(s):  
Hydrogen Generation ◽  
Highly Active
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