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At least 1,783 records · Page 99
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

The Importance of Getting it Right - Lessons from the Failure and Subsequent Approval of the LLWR Environmental Safety Case - 16691

The Low Level Waste Repository (LLWR) in the UK submitted an Environmental Safety Case in 2002 which was rejected by the Environment Agency 3 years later. Almost a decade after the rejection, the LLWR submitted a completely different document which was approved in November 2015. This paper looks at the lessons learned from the failed submission and documents the strategy employed by the Site's new contractor to overcome both the challenging technical issues that led to the initial rejection and overcome the resistance to long term disposal by the local community. It will describe the journey it has taken to move from a flawed safety case, to a technically sound safety case, to one that is approved by the regulator, and accepted by the community. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Issues Affecting the Assessment of Impacts of Disposal of Radioactive and Hazardous Waste - 18177

BIOPROTA is an international collaborative forum that seeks to address the key uncertainties in long term assessments of radionuclide and other contaminant releases into the environment arising from solid radioactive waste disposal. (see www.bioprota.org). Two workshops have been organized through the BIOPROTA forum to consider the non-radiological post-disposal impacts of radioactive waste disposal. In these workshops, it was noted that, ideally, the assessment of radionuclides and hazardous materials should be such that consistent assumptions and criteria are used in risk evaluation and that in cases where this is not possible, a clear understanding of the reasons why needs to be provided. Accordingly, a detailed review was organized through BIOPROTA to provide information to support development of a consensus on how to address this issue. The study suggests that there is a continuing need for some common measure of hazard that supports identification of risk management priorities for mixed hazardous waste. Without it, effective optimization of management of these mixed hazardous wastes will be restricted. (authors)

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DOE OSTI2018

NAMP Radiochemistry Webinars: The Next Educational Tool for the Next Generation Workforce - 18386

With an aging work force and only a few universities offering programs in radiochemistry, laboratories are increasingly finding it more challenging to hire and retain qualified radiochemists. Further, this challenge is a growing trend being seen worldwide. Expertise in radiochemistry is vital to advance our nation's progress in development of the next generation of nuclear reactor technology, drug discovery, environmental stewardship, and the development of technologies to prevent and respond to nuclear terrorist events. The National Analytical Management Program (NAMP) Education and Training subcommittee was established in response to the challenge of promoting radiochemistry and maintaining a well-educated work force to meet the projected growth in nuclear medicine, nuclear energy, safeguards, and nuclear forensics. The NAMP Education and Training subcommittee has offered radiochemistry webinars to a broad audience and is educating and strengthening the knowledge of participants in applications related to actinide and fission products chemistry, sample preparation, detection, dosimetry, nuclear forensics, nuclear fuel cycle, nuclear forensics, and risk assessment. These webinars are presented by renowned experts in the field of Radiochemistry. Additionally, through the partnering of the Education and Training subcommittee with various universities, the NAMP webinars offer a platform for graduate students, PhD candidates, and postdoctoral students to present their research to a wider audience. Since 2012, NAMP has conducted monthly, live webinars - all of which are recorded and archived as an online educational resource to the public from the NAMP web site (http://www.wipp.energy.gov/namp). With over 50 archived presentations, the NAMP webinars provide a comprehensive and interdisciplinary examination of radiochemistry topics. By partnering with university professors and renowned scientific professionals, the NAMP continues to expand the list of webinar topics, increasing the depth of knowledge in this online resource and rapidly becoming the next educational tool in radiochemistry for the next generation workforce. (authors)

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DOE OSTI2018

Achieving the Vision: An Update on Cleanup, Closure, and Reindustrialization of the East Tennessee Technology Park - 18401

URS-CH2M Oak Ridge LLC (UCOR) is responsible for cleanup of the U.S. Department of Energy's (DOE) East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee. Formerly known as the K-25 site, the facility enriched uranium for major defense nd energy programs for more than 40 years. The site's industrial processes - largely the gaseous diffusion method used for enriching uranium - left behind radioactive, chemical and industrial contaminants in soils and structures. Cleanup of the environmental legacies enables DOE's goal for converting ETTP into a private sector industrial park. Return of the restored site to the community will attract new industries to the region, creating jobs and growing the economy. The central elements to achieve DOE's vision for the site are 1) Cleanup, 2) Closure, and 3) Reindustrialization. Cleanup entails completion of all demolition activities and remedial actions consistent with the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA) agreements. Closure leaves facilities and infrastructure in a condition that enables transfer of the site to non-federal entities and reduces DOE's long-term stewardship costs. Closure activities include: - Infrastructure stabilization (site utilities, roads, stormwater, etc.); - Disposal or transfer of government property; - Relocation of most DOE contractors and support functions offsite; - Transfer of the majority of the site property to non-federal entities for redevelopment. Reindustrialization enables DOE's vision for the site as a multi-use private sector industrial park, reducing DOE's costs and enhancing the local economy. Transfer to the private sector will be accomplished through the Community Reuse Organization of East Tennessee (CROET), which will serve as the Park Manager. (author)

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DOE OSTI2018

Addressing Excess Contaminated Facilities and Mercury Cleanup At the Department of Energy's Oak Ridge Reservation - 18408

The U.S. Department of Energy's Oak Ridge Office of Environmental Management (OREM) and its prime cleanup contractor, URS | CH2M Oak Ridge LLC (UCOR) are executing an aggressive program of cleanup and risk reduction in excess contaminated facilities on the Oak Ridge Reservation (ORR). Across the complex, DOE has designated more than 2,300 of its facilities 'excess'. Excess means 'nonoperational' and refers to a facility for which DOE no longer has a mission need. Many of these facilities pose high risk to workers and/or the environment. Delayed cleanup increases risk as well as cost. OREM and UCOR initiated a Working Group on Excess Facilities to identify and prioritize activities that are needed to enhance worker safety, minimize further degradation of the facilities, and reduce the environmental risk. Six Excess Contaminated Facilities projects on the ORR were identified as priorities. Three of the projects are located at ORNL - the Building 7500 Homogenous Reactor Experiment, the Building 3026 Radioisotope Development Laboratory and Buildings 3028/3029 Isotope Facilities. At Y-12, priority excess facilities include the Column Exchange Equipment (COLEX), the Alpha-4 Lithium Enrichment Facility and the Biology Complex Research Facilities. Work on these projects is aimed at stabilization of degraded higher risk facilities, characterization of conditions and hazards, removal of hazardous materials and placement of the facility in the lowest risk condition possible pending demolition. At the same time, DOE and UCOR are preparing to undertake a comprehensive program to remediate the presence of mercury in the water stemming from historical operations at the Y-12 National Security Complex. Over decades of operations, mercury migrated into the environment. Deteriorating conditions of large post-operation mercury-use buildings may be contributing to additional releases. Mercury cleanup is a high priority for Y-12 and the Oak Ridge Reservation. UCOR is completing the final design on a new Mercury Treatment Facility with construction expected to begin in late 2017. When constructed the treatment facility will reduce the amount of mercury in local waters, lower environmental contamination levels and serve as a guard against future releases. (author)

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DOE OSTI2018

Optimising National WM Strategies through early consideration of Nuclear Safeguards - 18607

International Atomic Energy Agency (IAEA) safeguards stand alongside safety and security as one of the three pillars for prudent management of all nuclear material, including nuclear waste. Although safety considerations, including public and environmental radiation protection, are the traditional drivers of waste management strategies, there is a requirement for nuclear safeguards in shaping and quantifying long-term solutions for special classes of radioactive waste. This is especially important when considering the disposal of nuclear material in a repository that could be released from regulatory oversight for radiation protection after a period of institutional control, as some safeguards oversight would still be required. Failure to consider nuclear safeguards at the early stages of planning may alternatively lead to excessive volumes for disposal or the need to recondition already treated wastes. At the very least, safeguards measures should be considered before countries seek to dispose of legacy nuclear materials, decommissioning wastes and other materials containing uranium, thorium or plutonium in an operating repository. Nuclear safeguards are the set of tools and techniques used by the IAEA to verify that countries comply with their international obligations not to divert nuclear materials to nuclear explosive devices. Under the Nuclear Non-Proliferation Treaty (NPT), nuclear safeguards apply to all uranium, thorium and plutonium held in non-weapons NPT states, with limited exceptions. In nuclear-weapon states, much of their material is likewise subject to IAEA safeguards through conditions in agreements with respective suppliers of the uranium. Under IAEA safeguards, such nuclear material must remain accounted for and accessible for periodic verification-analogous to the safety concepts of reversibility and retrievability. Nevertheless, safeguards requirements can be terminated - provided that the State and the [IAEA] agree that such nuclear material is practicably irrecoverable - through dilution or immobilisation in solid form (such as cement, glass or ceramic). This means candidate material can be disposed of as non- nuclear material, with no further safeguards requirements, provided this criterion is met. Unlike radiological wastes where repository design strongly influences pathways for radionuclide migration and overall safety performance, repository design is not a factor in considering the termination of safeguards on nuclear material. This paper looks at similarities and differences in the safety, security and safeguards regulatory requirements for the management of radioactive waste and nuclear material in Australia. In particular, it outlines recent experience gained from participation in Australia's waste acceptance criteria working group for a national low-level waste repository and intermediate-level waste store, as well as from Australia's overall waste management strategy. These items of work have coincided with the IAEA update of its internal policy on termination of safeguards on nuclear material. Australia's experience shows how inclusion of safeguards criteria in the planning process is leading to optimisations in choice of facility concepts, project sequencing and equitable distribution of economic risk. By considering the three pillars-safety, security and safeguards-early on in the planning process, Australia's waste management strategy will provide a benchmark for other states in establishing and updating their own waste acceptance criteria for the disposal of nuclear material. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Commissioning and Startup of a New Category 2 Nuclear Facility for RH TRU Sludge Packaging - 18614

For many years the Department of Energy (DOE) has been executing a plan to eliminate all threats of Radiological release to the Columbia River from the Hanford site, in Richland, Washington. While the River Corridor Closure Project is nearing completion, one of the last remaining facilities along the Columbia River is the 100K reactor complex. Since the 1950's the 105KW fuel storage basin has contained varying levels of spent reactor fuel and products of the degradation of aging stored fuel. Having previously removed all of the distinguishable spent fuel components, CH2M HILL Plateau Remediation Company (CH2M) is now in the final stages of readiness review to commence removal of the residual sludge material that has accumulated in the basin throughout the years of operation. There is approximately 27 m3 of sludge in the 105KW basin currently. This sludge material exhibits a very high radiation dose rate with levels reaching 100 R/hr. It is also very difficult to mobilize and transfer due to its physical characteristics. CH2M engineers have developed a novel mechanical system for mobilization and transfer of the sludge to specially designed storage containers. Once transferred to these containers, the sludge will be moved away from the river and taken to T Plant, a decontamination and repair facility on site, for interim storage, while a project to treat and package the material for final disposition is established. The Sludge Removal Project (SRP) is a $309 M capital line item project that was established to achieve the goals of this mission. Part of the project is to develop and install the equipment needed to do the transfer, and part of the project is to construct a new Category 2 sludge packaging facility. Construction of the facility is now complete, all equipment is installed and the project is well into the commissioning phase. Over the final three months of 2017, the project progressed into the final stages of readiness to transition to operations. This will represent the first commissioning of a new Category 2 process and facility at Hanford in over 10 years. The SRP team has crossed over many hurdles in establishing a workable plan for the safety basis for installing, commissioning and transitioning to operations within the boundaries of an existing Facility Safety Analysis Report. The project team has also applied extensive use of a mockup facility in the development and execution of the path to readiness and commencement of operations. At the time of the conference, the project will have completed a DOE Operational Readiness Review and will be very near of just entering full operation. This paper will share the experiences of the project team through these final steps and lessons learned on making the project successful. (author)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Streamlining Stakeholder Data Accessibility Utilizing Web-Based GIS Capabilities - 18672

Environmental data is often complex, and it can be difficult to provide proper context to fully understand and comprehensively analyze the data. One tool identified to better present complicated data is the use of web-based Geographic Information Systems (GIS). Web-based GIS provides much-needed visual context to the complex data collected at Los Alamos National Laboratory (LANL). By overlaying environmental data atop relevant geographical features, such as topography, surface or subsurface geology, hydrogeological features, buildings, roads, and technical areas, LANL's diverse group of stakeholders are better able to understand environmental data collected at the LANL site within the framework of the surrounding geography. Since 2012, Los Alamos has utilized a web-based GIS module in the Intellus New Mexico data-sharing web site. This web site provides unfettered public access to LANL and New Mexico Environment Department (NMED) - Department of Energy (DOE) Oversight Bureau environmental data. Through the past five years of real world experience, LANL identified areas where questions and confusion arose, particularly for those not directly associated with the site's environmental cleanup mission. In order to query the millions of records in Intellus in a meaningful way, users had to have substantial knowledge of the data organization and nomenclature ahead of time. While this was not a challenge for LANL and NMED environmental scientists, it proved to be a substantial barrier for members of the general public to utilize Intellus. In 2017, LANL initiated an Intellus redesign with the goal of deconstructing the type of questions people asked and identifying the types of user personas accessing the site to engineer a simpler path to desired data sets. Greatly simplified click paths ('Quick Paths') were created that walk the user through the basics with a minimum of jargon and a strong reliance on mapping results for easy visualization. The improved mapping was enabled by an upgraded online GIS functionality that allowed LANL to easily integrate their own base-maps to provide users the most up to date views of their data. The integrated Intellus GIS was enhanced to assimilate with LANL's dynamic base maps and site information in relation to data collection activities, to avoid outdated presentations. A simplified user interface (UI) was added and easier data querying was designed. A more robust visual presentation was created that allowed better viewing of spatial data. All data queries in the new simplified 'Quick Path' give the users the option to map the results and save their results to their optional accounts. This brings the power of GIS visualization to all users without the need for GIS knowledge or extensive training. By integrating with Esri{sup R} technologies, base-map layers in ArcGIS Online{sup R} can be updated by LANL or other data providers at any time and reflected immediately in the Intellus mapping application called GIS+ 1. Users can even load additional map layers to GIS+ that contain their own spatial data or information shared from over a million users on ArcGIS Online{sup R}, such as ecological information from the Fish and Wildlife Service, or geology layers from the USGS. The results from the improved quick path search in Intellus can be viewed in GIS+ and analyzed using Esri's{sup R} Smart Mapping technology, which makes it easy to classify results with its visual representation of the results in an interactive histogram, where sliders can be dragged to look at various intervals for each color range for that query. With enhanced GIS+, Los Alamos National Laboratory is able to observe improve Stakeholder engagement and positive Stakeholder interactions within its public environmental database, Intellus New Mexico. (authors)

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DOE OSTI2019

Panel Session 2: 30 Year Anniversary of US DOE-Environmental Management-EM Update

This panel focused on Senior US DOE Managers from Washington, D.C. speaking on the pressing issues facing US DOE EM sites and the 30 year anniversary of DOE - EM. The panel was moderated by Martin Schneider, Longenecker and Associates. Presentations proposed include: 1 - DOE Environmental Management Update From EM-2 (Mark Gilbertson, US DOE EM (USA)); 2 - DOE Environmental Management Update From EM-3 (Jeffrey Griffin, US DOE EM (USA)); 3 - DOE Environmental Management Update From EM-4 (Betsy Connell, US DOE EM (USA)); 4 - DOE Environmental Management Update From EM-5 (Steve Trischman, US DOE EM (USA))

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Leveraging Environmental Monitoring Results from Department of Energy Sites for Research on the Food-Energy-Water Nexus

The Annual Site Environmental Report (ASER) from a U.S. Department of Energy (DOE) Site summarizes environmental data; environmental management performance; compliance with applicable DOE, federal, state, and local regulations; and restoration and surveillance monitoring programs. The Savannah River Site (SRS) produces ASERs that include results of monitoring mercury levels in fish samples obtained in the vicinity of SRS. Mercury is a toxic trace metal and the methylated organic form is a neurotoxin that bioaccumulates in the food web, endangering humans and other organisms. In United States, power plants are the largest source of mercury emissions. Research Objective: To determine the patterns of mercury levels in fish samples reported in the SRS environmental monitoring reports. We developed box plot visualizations to make sense of the data as well as identify fish species, dates and location with outlier mercury content. The integration and visual representation of multi-year datasets can support decision making processes on environmental compliance and environmental sustainability conducted at U.S. DOE Sites. We are constructing datasets from textual, image and multivariable data sources in the multi-year ASERs of the U.S. DOE Savannah River Site (SRS https://www.srs.gov/general/pubs/ERsum/index.html). The Fish Surveillance for mercury presents a case study for the intersection of food, energy and water systems. The dataset of 864 records (2008 and 2009) of mercury levels includes water location of fish, fish species, collection date and mercury content of fish sample. The patterns of mercury levels in the fish species as well as locations provide knowledge for further investigations. A research area for future studies is the composition of microbial communities in fish guts of varying levels of mercury.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Nuclear Decontamination Evolution and Revolution - 20349

Decontamination, one of the oldest practices in the nuclear industry, is about to change. While no single approach to decontamination is appropriate in all situations, decontamination of highly contaminated surfaces is historically viewed as difficult and/or marginally effective and fixatives and strippable coatings are often called on to manage time sensitive contamination control issues. The deferral of proper decontamination can lead to accumulated concentrations of radioactive material increasing the risk of cross-contamination of workers and equipment while also increasing radiation levels, which further discourages decontamination. The results of the subject testing demonstrate that superior decontamination factors are readily achievable and the ALARA benefit of decontamination is viable through advanced decontamination technologies in conjunction with innovative application techniques. The collateral benefits will save countless radiological man-hours and personnel radiological exposure. The appropriate use of radiological decontamination techniques can prevent or limit the adverse effects of highly radioactive contamination in the work area. High levels of radiological contamination are typically associated with some of the most physically demanding work in the nuclear industry. Additionally, working in highly contaminated environments increases the risk of exposure to elevated levels of airborne radioactivity and radiation from the source term of the contamination, particularly in hard to reach areas or complex equipment. Veolia's Alaron Nuclear Services (Alaron), a fully integrated nuclear facility, has provided the nuclear industry waste treatment, consolidation, repackaging, and broad decontamination services for almost 35 years. In looking at solutions for its customers, as well as for their own facility, Alaron has recently collaborated with Environmental Alternatives, Inc. (EAI), which has provided innovative solutions addressing difficult nuclear decontamination and industrial cleaning challenges since 1989. This broad range of experience along with the products to support the work created an ideal partner for Alaron's needs at their facility. The benefits of collaboration were immediately recognizable to the management of both companies although the decontamination challenge was significant. Due to the nature of the services offered, contamination at the Alaron facility is routine. The recent decontamination experience at Alaron utilized an innovative surfactant process that quickly produces remarkably higher decontamination factors for both removable surface contamination and fixed contamination. Considering the time to decontaminate areas historically designated for high radiological hazard work, the results from this decontamination effort not only reduced contamination levels but also significantly lowered exposure rates in the working environment. The relative ease with which the surfactant is applied, combined with extraordinary decontamination test results, indicates the potential to alter current radiological work processes in a way that improves worker comfort, and removes radiological engineering barriers, allowing Alaron to complete complex radiological tasks more efficiently and effectively. In a series of two simple applications of the decontamination agent to contaminated high bay vertical surfaces, as well as a variety of horizontal and vertical surfaces with variable porousness and surface sealants, there was an overall reduction in removable contamination of approximately 73% with a reduction in area dose of approximately 93%. The results indicate additional reduction in fixed contamination with application of the surfactant. These values are much higher than experienced with more traditional decontamination agents. In conjunction with demonstrating EAI's surfactant on room surfaces, additional studies were conducted on complex geometry equipment including waste processing equipment, tools, and heavily contaminated parts normally handled from Alaron's customers. Evaluations were made with straight application of EAI's surfactant as well as adding additional techniques to the treatment which afforded revolutionary improvements in the levels of contamination removed. Successful decontamination with up to 95% reduction in removable contamination with just one application were demonstrated in several of the trials. This paper outlines the planned approach to use this technology, the variety of surfaces and equipment treated, and the results of the decontamination efforts. Furthermore, this paper discusses options for pretreatment of certain heavily contaminated equipment prior to employees handling and/or working with the equipment. The potential for dose saving and the reduced risk of cross-contamination with the added benefit of lower PPE requirements, produces an enormous potential for cost and time savings. Attendees will benefit from Alaron's experiences and more fully understand the capabilities of EAI's decontamination process. With the variety of contamination agents, forms and surfaces on which the technology was demonstrated, the information will be valuable to a broad cross-section of industry users. The significance of this report demonstrates superior decontamination factors are achievable utilizing the next evolution of decontamination technology and that the ALARA benefits of decontamination are available through advanced and modern decontamination efforts. The collateral benefits will save countless radiological man-hours and valuable personnel radiological exposure. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Robust Method to Identify Groundwater Affected By Redox Conditions at Los Alamos National Laboratory Legacy Cleanup Site - 20497

To facilitate the mission of the Department of Energy's (DoE's) Environmental Management Program at Los Alamos National Laboratory (LANL), a significant number of groundwater monitoring wells with depths ranging from 152-396 meter were completed for characterization and monitoring. Groundwater at Los Alamos tends to be oxygen saturated with very low concentrations of organic matter. Drilling fluids can introduce residual carbon causing an increase in microbial activity and local reducing conditions around the well, potentially impacting representativeness of groundwater data quality for redox sensitive constituents. We assert that the redox state of the wells can robustly be identified by aqueous solution concentrations of iron and manganese. An automated review process has been built into a computer-based data management system enabling an efficient screening process for identifying reducing conditions that are not caught using standard data-validation protocol, and ensures that important data quality issues are thoroughly identified and addressed in an efficient and timely manner. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Sludge Removal: Success and Partnership with T Plant - 20510

U.S. DOE contractor CH2M Hill Plateau Remediation Company (CHPRC) has safely and efficiently managed the removal of highly radioactive sludge from the 105-K West Reactor fuel storage basin (105- KW Basin) near the Columbia River. In mid-September 2019, sludge retrieval was completed after 21 storage containers were safely loaded with highly radioactive sludge and transported approximately 13 miles from the 105-KW Basin to T Plant, located in the 200 West Area on the Central Plateau of the Hanford Site. Sludge removal represents the last major source term reduction necessary before the K West Reactor and fuel storage basin can transition to closure activities in preparation for final deactivation and demolition. The technical complexity of the sludge retrieval process, coupled with the challenging physical and radiological characteristics of the waste, necessitated a methodical and deliberate approach using unique design and operational solutions to safely conduct the work. This challenge was further complicated by the need to plan and conduct the work in two separate facilities, each subject to the controls and requirements of its own nuclear facility safety basis. The project overcame these challenges through creating an integrated team that actively engaged, communicated and coordinated each phase of the project to ensure successful completion. This paper will cover how these key elements of the Sludge Removal Project led to its success: - Integrating project planning and management; - Lessons learned from design and construction; - Preparing for a successful campaign (lessons learned from testing and start-up); - Lessons learned from operating in two separate facilities, transporting sludge containers on the Hanford Site and ensuring compliance with a range of regulatory and safety basis requirements. The establishment of an integrated group spanning two facilities and multiple organizations created a team capable of overcoming the challenges necessary to successfully plan and execute the sludge retrieval mission. Sharing lessons learned from this successful project can enhance the ability of teams across the DOE complex to successfully plan and execute complex projects. (authors)

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DOE OSTI2015

An approach to evaluating and monitoring ecological resources for sustainability on DOE remediation sites: Hanford as a case study - 15524

Protecting ecological and environmental resources is a worthy aspect of the Department of Energy's site missions, for each of its sites, during and after remediation. Ecological resources are important to a range of stakeholders, including regulatory agencies, resource agencies, natural resource trustees, Tribal governments, and the public, and may be an essential component of Native American cultural resources. Because the nature and value of ecological resources can change over time as a result of remediation, succession, and global climate change, it is imperative for DOE to have instituted an acceptable method of evaluating resources before initiation of active remediation, over the ensuing century when institutional and engineering controls are considered to be in effect. Having such a methodology in place also would be key to resource sustainability. Department of Energy sites generally have environmental programs, so instituting specific unified practices for evaluating resources should not be difficult to implement. Instituting these practices would assure the public that ecological resources, as well as human and cultural resources, are being protected now, and can be protected into the future. Key ecological species and/or unique habitats have been preserved at Department of Energy sites since the mid-20. century because of federal government stewardship. Such preservation is particularly true for the sites with larger land areas, including the Hanford Reservation, the Idaho National Laboratory and the Savannah River Site. Individual sites typically have extensive studies of site biodiversity, but site resources are not routinely examined within a regional or national context (Eco-region). The evaluation of the on-site resources with those resources in the appropriate Eco-region provides a context for 'valuing' on- site resources. On-site resources should also be evaluated in terms of federal and state legislation where species may have legal protection and require legal consideration during remediation if present or adjacent to the remediation site. A method is needed in this study for evaluating ecological resources prior to remediation and during remediation, and a paradigm is proposed that will ensure sustainability. Finally, in a period of climate change and instability, developing methods of evaluating ecological resources is essential to successful protection, enhancement, and sustainability. The ecological methodology is part of a Hanford site-wide Risk Review Project, conducted by the Consortium for Risk Evaluation with Stakeholder Participation (CRESP). Our method adapts an existing methodology that includes using established levels for evaluating ecological resources by expanding the existing methodology to include field work for validating previous resource level designations, to assess the occurrence of invasive/exotic species, and to identify landscape scale features (patch size, connectivity). Evaluations should be conducted in the remediation unit itself, and in a buffer zone surrounding the remediation site. The methodology described has been applied to several remediation areas at Hanford, and issues that emerged during its application are discussed. The methodology can be applied at the major sites. Application of the Eco-region analysis will provide regulators and the public with an understanding of the value of the ecological resources in relation to the region, as well as an appreciation for the stewardship role the Department of Energy has played in protecting these resources since the beginning of the Cold War Era and can continue to do so sustainably. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Modelling an induced thermal plume with data from electrical resistivity tomography and distributed temperature sensing: a case study in northeast Italy

Groundwater tracer tests are often used to improve aquifer characterization, but they present several disadvantages, such as the need to pour solutions or dyes into the aquifer system and alteration of the water’s chemical properties. Thus, tracers can affect the groundwater flow mechanics and data interpretation becomes more complex, hindering effective study of ground heat pumps for low enthalpy geothermal systems. This paper presents a preliminary methodology based on a multidisciplinary application of heat as a tracer for defining the main parameters of shallow aquifers. The field monitoring techniques electrical resistivity tomography (ERT) and distributed temperature sensing (DTS) are noninvasive and were applied to a shallow-aquifer test site in northeast Italy. The combination of these measurement techniques supports the definition of the main aquifer parameters and therefore the construction of a reliable conceptual model, which is then described through the numerical code FEFLOW. This model is calibrated with DTS and validated by ERT outcomes. The reliability of the numerical model in terms of fate and transport is thereby enhanced, leading to the potential for better environmental management and protection of groundwater resources through more cost-effective solutions.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

Environmental degradation of high-temperature protective coatings for ceramic-matrix composites in gas-turbine engines

Abstract The need for higher efficiencies and performance in gas-turbine engines that propel aircraft in the air, and generate electricity on land, is pushing the operating temperatures of the engines to unprecedented levels. Replacing some of the current hot-section metallic components with ceramic-matrix composites (CMCs) is making that possible. A high-temperature ceramic coatings system, that includes environmental-barrier coatings (EBCs), are needed to protect CMCs. However, these coatings undergo degradation in the highly hostile environment of the gas-turbine engine consisting of a combination of high gas temperatures, pressures, and velocities. In addition, there is the ubiquitous presence of steam (a combustion by-product) and occasional ingestion of calcia-magnesia-aluminosilicates (CMASs) in the form of dust, sand, or ash from the environment. Steam can cause corrosion of EBCs, and the molten CMAS deposits can react with the EBCs resulting in their failure. This article provides a perspective on the understanding of these degradation mechanisms, and possible approaches, guided by that understanding, for mitigating the degradation. An outlook on the future challenges and opportunities is presented.

Padture, Nitin P. (ORCID:0000000166228559)↗