SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Researchers from Los Alamos National Laboratory (LANL) performed measurements during a series of Godiva IV bursts to determine the effectiveness of engineering controls to reduce contamination. (authors)
Internal dosimetry controls require the use of engineering controls to prevent the internal deposition of radioactive and nonradiological contaminants. However, when engineering and administrative controls are not available or feasible, respiratory protection may be necessary. The radiation control technician (RCT) should know and apply the considerations used in determining the respiratory protection equipment that is most appropriate for the job. The inappropriate use of or the use of the wrong respiratory protection equipment may result in undesirable health effects. This course will prepare the student with the skills necessary for RCT qualification by passing quizzes, tests, and the RCT Comprehensive Phase 1, Unit 2 Examination (TEST 27566) and will provide in-the-field skills.
Internal dosimetry controls require the use of engineering controls to prevent the internal deposition of radioactive and non-radiological contaminants. However, when engineering and administrative controls are not available or feasible, respiratory protection may be necessary. The RCT should know and apply the considerations used in determining the respiratory protection equipment that is most appropriate for the job. The inappropriate use of or the use of the wrong respiratory protection equipment may result in undesirable health effects.
Gloveboxes used for processing plutonium (Pu)-238 at the US DOE Mound site in Miamisburg, Ohio, in support of the United States space mission were packaged in non-standard waste boxes and sent to the INL Site for temporary disposal. In addition to the gloveboxes, an assortment of smaller items, all with varying levels of Pu-238 contamination, were found in the non-standard waste boxes. The characteristics of Pu-238 make it especially difficult to contain and control contamination; alpha recoil phenomena and nanometer particle sizes lend to the contamination exhibiting near gas like characteristics. The Idaho Cleanup Project Core contractor, Fluor Idaho, LLC, engineered and deployed a waste processing containment with specialized ventilation and processes to characterize and disposition this waste. This paper summarizes the successes and lessons learned from processing Pu-238-contaminated waste. (authors)
When the nation's top scientists and military leaders converged on Los Alamos, New Mexico in the 1943, to work on the Manhattan Project, the facilities they used to conduct their top-secret work were quickly constructed and located in the middle of what eventually became the Los Alamos town site. After one of these early facilities caught on fire, it seemed wise to build labs and production facilities farther away from the homes of the town's residents. They chose to build facilities on what was then known as Delta Prime (DP) Mesa and called it Technical Area 21, or TA-21. With wartime urgency, a number of buildings were built at TA-21, some in as little as a few months. Before long, DP Mesa was populated with several nondescript metal and cinder-block buildings, including what became, immediately following the war, the world's first plutonium production facility. TA-21 also housed labs that used hazardous chemicals and analyzed americium, tritium and plutonium. TA-21 was a bustling center of research and production for the next several decades. Additional buildings were built there in the 1960's, but by the 1990's many of them had reached the end of their service lives. Labs and offices were moved to newer, more modern buildings. When Los Alamos National Laboratory received $212 million in funding from the American Recovery and Reinvestment Act in July 2009 for environmental cleanup projects, about $73 million of the funds were earmarked to decontaminate and demolish 21 of the old buildings at TA-21. Although some D and D of TA-21 buildings was performed in the 1990's, many of the facilities at DP Site remained relatively untouched for nearly three decades following their final operational use. In 2006, there were over three dozen buildings or structures on the mesa to be removed so that soil cleanup could be completed (and the land made available for transfer and reuse). The total footprint of buildings across the mesa was approximately 18,580 m{sup 2} (200,000 ft{sup 2}). The initially approved baseline for the ARRA D and D Project was to remove 22 buildings and structures that included approximately 14,680 m{sup 2} (158,000 ft{sup 2}) of footprint. By employing efficiencies during subcontracting, demolition, and waste segregation, the savings allowed an additional 1,580 m{sup 2} (17,000 ft{sup 2}) of footprint to be removed using ARRA funds. Additionally, the lessons learned from this experience were used to apply NNSA funding to the removal of six additional non-contaminated buildings and structures. In the end, 29 buildings and structures, including stacks, cooling towers and tanks, were removed from the mesa. The entire DP East area was cleared of buildings and sub-grade structures and the soils cleaned to residential standards. The total footprint reduction at TA-21 as a result of this effort was in excess of 17,650 m{sup 2} (190,000 ft{sup 2}). The use of a Laboratory self-performance team to start demolition of non-contaminated structures resulted in steady work performance early in the project while subcontracts were being put in place to perform more complicated abatement and contaminated demolition activities. Most importantly, there were no serious worker injuries and the minor injuries recorded were those common to construction type activities. Extensive monitoring along the site boundary demonstrated that no hazardous chemicals or radioactive contamination were released and radiological dose to the public was negligible. The ARRA demolition activities were completed six months in advance of the deadline for employing ARRA funds. Additionally, over 17,585 m{sup 3} (23,000 yds{sup 3}) of building demolition debris was safely removed from DP Mesa. All of the major buildings have been removed, unencumbered access to the SWMUs that are required to be cleaned up by the Consent Order with the state of New Mexico, has been achieved, and a significant portion of the mesa has been prepared to support a process that will eventually transfer this land from federal government control for further use. (authors)
The Decontamination and Decommissioning (D and D) Operations take place in hostile environments to the human intervention. In this context, robotic systems are a solution to achieve these operations while minimizing human intervention. Among these operations, the monitoring of lengthwise plant has to be performed in places where the radioactive contaminations make hostile environments. These monitoring operations need to measure several physics parameters in several locations in a precise and safe manner. These repetitive tasks can be made by robots that are simple, small sized and easily adaptable. In this scope, a robotic system on cables has been designed to control and monitor the inside of lengthwise nuclear facilities. In lengthwise installations, the using of cables allows to increase the covered zone of the robots which is an essential quality in such places. Unlike cable-driven parallel robots used in workspaces of 2D or 3D controlled by redundant tensioning motors, the current robot moves in a 1D workspace. Thus a tractors cable controlled by one tensioning motor is used to drive the robot on carrier cables. In this paper, we will describe the first results of this work by bringing out the innovation of our system. Then, we will discuss the perspective to upgrade the actual system whose applications could be perfectly imagined outside the nuclear D and D industry. (authors)
This report focuses on the detection and control of radioactive contamination, which are an integral part of an aggressive ALARA program and provide an indication of the effectiveness of engineering controls and proper work practices in preventing the release of radioactive material. Radioactive contamination, if undetected or not properly controlled, can be spread and contaminate areas, equipment, personnel, and the environment.
Highlights: • A low-cost soil lead mitigation project in Vietnam is detailed and assessed. • The effort resulted in substantial declines in biological and environmental lead levels. • The approach could be replicated elsewhere to address a commonly occurring issue. This study details the first comprehensive evaluation of the efficacy of a soil lead mitigation project in Dong Mai village, Vietnam. The village's population had been subject to severe lead poisoning for at least a decade as a result of informal Used Lead Acid Battery (ULAB) recycling. Between July 2013 to February 2015, Pure Earth and the Centre for Environment and Community Development (Hanoi, Vietnam) implemented a multi-faceted environmental and human health intervention. The intervention consisted of a series of institutional and low-cost engineering controls including the capping of lead contaminated surface soils, cleaning of home interiors, an education campaign and the construction of a work-clothes changing and bathing facility. The mitigation project resulted in substantial declines in human and environmental lead levels. Remediated home yard and garden areas decreased from an average surface soil concentration of 3940 mg/kg to <100 mg/kg. One year after the intervention, blood lead levels in children (<6 years old) were reduced by an average of 67%—from a median of 40.4 μg/dL to 13.3 μg/dL. The Dong Mai project resulted in significantly decreased environmental and biological lead levels demonstrating that low-cost, rapid and well-coordinated interventions could be readily applied elsewhere to significantly reduce preventable human health harm.
Land-use planning focusing on future disposition of public lands, forests and, former agricultural or industrial land, must take into account demographic and economic factors as well as future needs and availability of recreational open space, arable land, and water for growing populations. Planning requires the balancing of competing interests for 'growth', open space, and preservation of cultural, ecological and natural resources Landscapes with soil, surface water, and groundwater contaminated by former military, industrial, mining or agricultural uses, pose special challenges, many of which have been addressed under the rubric of 'brown-fields'. Land-use decisions or recommendations can be based mainly on economic/social interests taking into account projected demographic changes, or they can be based mainly on environmental issues taking into account contamination levels, remediation costs and technologies, and health risk issues. Future land-use is interwoven with cleanup goals. Where unrestricted future land-use is anticipated or desired, cleanup levels for soil and groundwater must be low enough to allow such uses without unacceptable health risks. Where such cleanup levels are unattainable for fiscal or technological reasons, residual contamination will remain, and future uses, particularly for groundwater, must be restricted, requiring engineered barriers and institutional controls to interdict future exposure pathways from contaminated environmental media to receptors (residents, recreationists, employees). Although contamination and hazard may persist for centuries, planning beyond a generation or two incurs great uncertainties in demographics, policies, economic, and climate-related changes. The Environmental Protection Agency and various states have established categories of clean-up levels corresponding to future industrial, recreational and residential use, with variations on these themes. This paper examines the spectrum of land-uses, and emphasizes a distinctions between -residential- and -unrestricted- as applied to future land-uses, particularly involving groundwater. Land-use determinations can be proposed and evaluated by a myriad of regulatory policies, guidance documents, and processes, including comprehensive land-use planning documents, Baseline Risk Assessments, Remedial Investigation/Feasibility documents and Records of Decision - which are not the focus of this study. This study instead focuses on gradations in different residential, recreational and industrial land-use scenarios and their relation to contamination of soil and groundwater. The Consortium for Risk Evaluation with Stakeholder Participation (CRESP) instituted this study to help understand the varying land-use versus clean-up decisions at the Department of Energy's environmental management sites, particularly Hanford (Washington State). (authors)
The US Department of Energy (DOE) is responsible for risk reduction and cleanup of its nuclear weapons complex. DOE maintains the largest cleanup program in the world, currently spanning over a million acres in 13 states. The inventory of contaminated materials includes 90 million gallons of radioactive waste, 6.4 trillion liters of groundwater, and 40 million cubic meters of soil and debris. It is not feasible to completely restore many sites to pre-disposal conditions. Any contamination left in place will require monitoring, engineering controls and/or land use restrictions to protect human health and environment. Research and development efforts to date have focused on improving characterization and remediation. Yet, monitoring will result in the largest life-cycle costs and will be critical to improving performance and protection. Through an inter-disciplinary effort, DOE is addressing a need to advance monitoring approaches from sole reliance on cost- and labor-intensive point-source monitoring to integrated systems-based approaches such as flux-based approaches and the use of early indicator parameters. Key objectives include identifying current scientific, technical and implementation opportunities and challenges, prioritizing science and technology strategies to meet current needs within the DOE complex for the most challenging environments, and developing an integrated and risk-informed monitoring framework. (authors)
The US Army Corps of Engineers (USACE) Buffalo District, with assistance from Argonne National Laboratory (Argonne), prepared a Site Closeout Report (SCOR) for the Linde Formerly Utilized Sites Remedial Action Program (FUSRAP) Site in accordance with Engineer Regulation (ER) 200-1-4 [1]. Under FUSRAP, USACE is authorized to investigate, and clean up or control sites contaminated as the result of actions by the Atomic Energy Commission (AEC) and its predecessor, the Manhattan Engineer District (MED), in support of the nation's early atomic energy and weapons program. The SCOR documents response actions conducted at the Linde FUSRAP Site between 1996 and 2013. These response actions include two non-time-critical removal actions and long-term remedies associated with the three operable units (OUs) at the site: 1) soils and structure surfaces (except Building 14), 2) Building 14, and 3) groundwater. The report summarizes the site history, previous investigations, selected remedies, remedial actions, waste disposal, community involvement, monitoring results, recycling, quality assurance/quality control practices, post-remediation dose assessment, remedial costs, and five year review requirements. (authors)
The US Department of Energy (DOE) is responsible for risk reduction and cleanup of its nuclear weapons complex. DOE maintains the largest cleanup program in the world, currently spanning over a million acres in 13 states. The inventory of contaminated materials includes 90 million gallons of radioactive waste, 6.4 trillion liters of groundwater, and 40 million cubic meters of soil and debris. It is not feasible to completely restore many sites to predisposal conditions. Any contamination left in place will require monitoring, engineering controls and/or land use restrictions to protect human health and environment. Research and development efforts to date have focused on improving characterization and remediation. Yet, monitoring will result in the largest life-cycle costs and will be critical to improving performance and protection. Through an inter-disciplinary effort, DOE is addressing a need to advance monitoring approaches from sole reliance on cost- and labor-intensive point-source monitoring to integrated systems-based approaches such as flux-based approaches and the use of early indicator parameters. Key objectives include identifying current scientific, technical and implementation opportunities and challenges, prioritizing science and technology strategies to meet current needs within the DOE complex for the most challenging environments, and developing an integrated and risk-informed monitoring framework.
The US Department of Energy (DOE) is responsible for risk reduction and cleanup of its nuclear weapons complex. DOE maintains the largest cleanup program in the world, currently spanning over a million acres in 13 states. The inventory of contaminated materials includes 90 million gallons of radioactive waste, 6.4 trillion liters of groundwater, and 40 million cubic meters of soil and debris. It is not feasible to completely restore many sites to predisposal conditions. Any contamination left in place will require monitoring, engineering controls and/or land use restrictions to protect human health and environment. Research and development efforts to date have focused on improving characterization and remediation. Yet, monitoring will result in the largest life-cycle costs and will be critical to improving performance and protection. Through an inter-disciplinary effort, DOE is addressing a need to advance monitoring approaches from sole reliance on cost- and labor-intensive point-source monitoring to integrated systems-based approaches such as flux-based approaches and the use of early indicator parameters. Key objectives include identifying current scientific, technical and implementation opportunities and challenges, prioritizing science and technology strategies to meet current needs within the DOE complex for the most challenging environments, and developing an integrated and risk-informed monitoring framework.
The US Department of Energy (DOE) is responsible for risk reduction and cleanup of its nuclear weapons complex. DOE maintains the largest cleanup program in the world, currently spanning over a million acres in 13 states. The inventory of contaminated materials includes 90 million gallons of radioactive waste, 6.4 trillion liters of groundwater, and 40 million cubic meters of soil and debris. It is not feasible to completely restore many sites to predisposal conditions. Any contamination left in place will require monitoring, engineering controls and/or land use restrictions to protect human health and environment. Research and development efforts to date have focused on improving characterization and remediation. Yet, monitoring will result in the largest life-cycle costs and will be critical to improving performance and protection. Through an inter-disciplinary effort, DOE is addressing a need to advance monitoring approaches from sole reliance on cost- and labor-intensive point-source monitoring to integrated systems-based approaches such as flux-based approaches and the use of early indicator parameters. Key objectives include identifying current scientific, technical and implementation opportunities and challenges, prioritizing science and technology strategies to meet current needs within the DOE complex for the most challenging environments, and developing an integrated and risk-informed monitoring framework.
Understanding air propagation and condensation following a catastrophic vacuum break in particle accelerator beamlines cooled by liquid helium is crucial for maintaining the operational safety of these facilities. Previous experimental investigations on nitrogen gas propagation in both normal liquid helium (He I) and superfluid helium (He II) cooled copper tubes unveiled a nearly exponential deceleration of the gas propagation. A comprehensive theoretical model incorporating gas dynamics, heat transfer, and condensation mechanisms has been developed, which effectively reproduces various key experimental observations. An intriguing phenomenon uncovered in our model simulation is that the gas propagation appears to nearly stop beyond a certain distance from the location where condensation starts. We refer to this distance as the freeze range. In this paper, we present our systematic study of the freeze range at various inlet mass fluxes and tube diameters. We show that the results can be well described by a simple correlation. The underlying physical mechanism that supports this useful correlation is explained. Knowing the freeze range may allow accelerator engineers to develop protocols for controlling frost-layer contamination in the beamline tubes, which is of great practical importance.
Los Alamos National Laboratory (LANL) is committed to the protection of the workers, public, and environment while performing work and uses gloveboxes as engineered controls to protect workers from exposure to hazardous materials while performing plutonium operations. Glovebox gloves are a weak link in the engineered controls and are a major cause of radiation contamination events which can result in potential worker exposure and localized contamination making operational areas off-limits and putting programmatic work on hold. Each day of lost opportunity at Technical Area (TA) 55, Plutonium Facility (PF) 4 is estimated at $1.36 million. Between July 2011 and June 2013, TA-55-PF-4 had 65 glovebox glove breaches and failures with an average of 2.7 per month. The glovebox work follows the five step safety process promoted at LANL with a decision diamond interjected for whether or not a glove breach or failure event occurred in the course of performing glovebox work. In the event that no glove breach or failure is detected, there is an additional decision for whether or not contamination is detected. In the event that contamination is detected, the possibility for a glove breach or failure event is revisited.
Solute transport and biogeochemical reactions in porous and fractured media flows are controlled by mixing, as are subsurface engineering operations such as contaminant remediation, geothermal energy production, and carbon sequestration. Porous media flows are generally regarded as slow, so the effects of fluid inertia on mixing and reaction are typically ignored. Here, we demonstrate through microfluidic experiments and numerical simulations of mixing-induced reaction that inertial recirculating flows readily emerge in laminar porous media flows and dramatically alter mixing and reaction dynamics. An optimal Reynolds number that maximizes the reaction rate is observed for individual pore throats of different sizes. This reaction maximization is attributed to the effects of recirculation flows on reactant availability, mixing, and reaction completion, which depend on the topology of recirculation relative to the boundary of the reactants or mixing interface. Recirculation enhances mixing and reactant availability, but a further increase in flow velocity reduces the residence time in recirculation, leading to a decrease in reaction rate. The reaction maximization is also confirmed in a flow channel with grain inclusions and randomized porous media. Interestingly, the domain-wide reaction rate shows a dramatic increase with increasing Re in the randomized porous media case. This is because fluid inertia induces complex three-dimensional flows in randomized porous media, which significantly increases transverse spreading and mixing. This study shows how inertial flows control reaction dynamics at the pore scale and beyond, thus having major implications for a wide range of environmental systems.
As a waste-volume reduction and management technique, highly contaminated Control Element Drive Mechanism (CEDM) housings were severed from the Reactor Pressure Vessel Head (RPVH) inside the San Onofre Unit 2 primary containment utilizing Oxylance high-temperature cutting equipment and techniques. Presented are relevant data concerning: - Radiological profiles of the RPVH and individual CEDMs; - Design overviews of the engineering controls and the specialized confinement housings; - Utilization of specialized shielding; - Observations of apparent metallurgical-contamination coalescence phenomena at high temperatures resulting in positive control over loose-surface contamination conditions; - General results of radiological and industrial hygiene air sampling and monitoring; - Collective dose and personnel contamination event statistics; - Lessons learned. (author)