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At least 613 records · Page 34

Characterization of NUW-LHT-5m, A Lunar Highland Simulant

A new simulant of the lunar highlands regolith, NUW-LHT-5M, was designed by NASA and manufactured by Washington Mills. The simulant was based on Apollo 16 data and is a member of the NU-LHT-series. NASA’s Marshall Space Flight Center and Johnson Space Center have already purchased 3 metric tons of the simulant for advanced engineering work. In support of engineering uses of the simulant, we provided measurements of the simulant including: mineral abundance and composition, liberation, X-ray fluorescence (XRF), ferrous iron, carbon, sulfur, 60 element inductively coupled plasma (ICP), loss on ignition, particle size, both 2D and 3D particle shape, specific surface area, shear, cohesion, internal friction, helium pycnometry, minimum index density, tap density, magnetic susceptibility, cryogenic and high temperature permittivity, visible and near-infrared (VNIR) and middle infra-red spectroscopy (MIR), differential scanning calorimetry (DSC), viscosity, thermal diffusivity, thermal conductivity, thermal gravimetric analysis (TGA), evolved gas analysis (EGA), and spark sintering. For the crystalline components the design of the simulant called for two rocks from the Stillwater Complex, Montana: 17.6 wt% norite, 37.7% anorthosite, and 4.7 wt% olivine from an unspecified commercial source. The other 40% of the simulant was a high calcium (An100), vesicular glass that Washington Mills made specifically for the simulant. Fabrication and quality control processes for both the glass and the simulant are described. Importantly, most of the graphs and tables presented herein provide values for both the new simulant and data for the older NASA mare simulant, JSC-1A. Finally, we discussed the current limitations of NUW-LT-5M and most other lunar regolith simulants to replicate the lunar material.

lunar regolith simulant↗

Solar Impulse's Solar-Powered Plane

Solar Impulse lands in Washington, DC at Washington Dulles International Airport as part of its journey across the United States. Secretary Ernest Moniz speaks about how advancements like those at the Department of Energy are leading the way for innovations like the solar-powered plane. Footage of the solar-powered plane courtesy of Solar Impulse.

14 SOLAR ENERGY↗

Future STEM Leaders Prepare for the National Science Bowl

Each year, students from across the country converge on Washington, DC, for the National Science Bowl, an intense academic competition that tests the students' knowledge in science, engineering, chemistry, math and Earth science. Follow one team, from Washington DC's Woodrow Wilson High School, as they prepare for and compete in the 2014 National Science Bowl.

99 GENERAL AND MISCELLANEOUS↗

Case Study in Corporate Memory Recovery: Hanford Tank Farms Miscellaneous Underground Waste Storage Tanks - 15344

In addition to managing the 177 underground waste storage tanks containing 212,000 m3 (56 million gal) of radioactive waste at the U. S. Department of Energy’s Hanford Site 200 Area Tank Farms, Washington River Protection Solutions LLC is responsible for managing numerous small catch tanks and special surveillance facilities. These are collectively known as “MUSTs” - Miscellaneous Underground Storage Tanks. The MUSTs typically collected drainage and flushes during waste transfer system piping changes; special surveillance facilities supported Tank Farm processes including post-World War II uranium recovery and later fission product recovery from tank wastes. Most were removed from service following deactivation of the single-shell tank system in 1980 and stabilized by pumping the remaining liquids from them. The MUSTs were isolated by blanking connecting transfer lines and adding weatherproofing to prevent rainwater entry. Over the next 30 years MUST operating records were dispersed into large electronic databases or transferred to the National Archives Regional Center in Seattle, Washington. During 2014 an effort to reacquire the historical bases for the MUSTs’ published waste volumes was undertaken. Corporate Memory Recovery from a variety of record sources allowed waste volumes to be initially determined for 21 MUSTs, and waste volumes to be adjusted for 37 others. Precursors and symptoms of Corporate Memory Loss were identified in the context of MUST records recovery.

Washenfelder, D. J.↗

Technetium Incorporation in Glass for the Hanford Tank Waste Treatment and Immobilization Plant

A priority of the United States Department of Energy (U.S. DOE) is to dispose of nuclear wastes accumulated in 177 underground tanks at the Hanford Nuclear Reservation in eastern Washington State. These nuclear wastes date from the Manhattan Project of World War II and from plutonium production during the Cold War. The DOE plans to separate high-level radioactive wastes from low activity wastes and to treat each of the waste streams by vitrification (immobilization of the nuclides in glass) for disposal. The immobilized low-activity waste will be disposed of here at Hanford and the immobilized high-level waste at the national geologic repository. Included in the inventory of highly radioactive wastes is large volumes of 99Tc (~9 × 10E2 TBq or ~2.5 × 104 Ci or ~1500 kg). A problem facing safe disposal of Tc-bearing wastes is the processing of waste feed into in a chemically durable waste form. Technetium incorporates poorly into silicate glass in traditional glass melting. It readily evaporates during melting of glass feeds and out of the molten glass, leading to a spectrum of high-to-low retention (ca. 20 to 80%) in the cooled glass product. DOE-ORP currently has a program at Pacific Northwest National Laboratory (PNNL), in the Department of Materials Science and Engineering at Rutgers University and in the School of Mechanical and Materials Engineering at Washington State University that seeks to understand aspects of Tc retention by means of studying Tc partitioning, molten salt formation, volatilization pathways, and cold cap chemistry. Another problem involves the stability of Tc in glass in both the national geologic repository and on-site disposal after it has been immobilized. The major environmental concern with 99Tc is its high mobility in addition to a long half-life (2.1×105 yrs). The pertechnetate ion (TcO4-) is highly soluble in water and does not adsorb well onto the surface of minerals and so migrates nearly at the same velocity as groundwater. Long-term corrosion of glass waste forms is an area of current interest to the DOE, but attention to the release of Tc from glass has been little explored. It is expected that the release of Tc from glass should be highly dependent on the local glass structure as well as the chemistry of the surrounding environment, including groundwater pH. Though the speciation of Tc in glass has been previously studied, and the Tc species present in waste glass have been previously reported, environmental Tc release mechanisms are poorly understood. The recent advances in Tc chemistry that have given rise to an understanding of incorporation in the glass giving rise to significantly higher single-pass retention during vitrification are presented. Additionally, possible changes to the baseline flowsheet that allow for relatively minor volumes of Tc reporting to secondary waste treatment will be discussed.

Kruger, Albert A.↗

Preparing for Harvesting Radioisotopes from FRIB

In the second quarter of this grant, work has progressed smoothly at all three collaborating institutions. We have recently completed our first experiment at the NSCL under this grant successfully, where 79Kr was collected by cryotrapping from our water target apparatus. The three PI’s, one undergraduate (Boone Marois), two graduate students (Stacy Queern and Matt Scott) and one post-doc (Aranh Pen) were assisted by Dave Morrissey at the NSCL to perform this experiment. The experiment also provided the opportunity for a collaboration meeting of the PI’s to discuss future work on this proposal. Significant progress has been made on both novel radiochemical separations technology at the University of Missouri, and validating a radiochemical separation procedure for 48V at Washington University. The only change in the work-scope of the original proposal is the transition of the Washington University PI to the University of Alabama at Birmingham.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

Modeling & Analysis of a Small Hydropower Plant and Battery Energy Storage System Connected as a Microgrid

Puget Sound Energy (PSE) is a utility with headquarters in Bellevue, WA that provides electric and gas service to customers in many regions of western Washington State. PSE is undertaking the implementation of a battery energy storage system pilot project in Glacier, WA, a small town located in the North Cascade Mountains near Mt. Baker Ski Area. Glacier experiences power outages that are both somewhat frequent and lengthy (roughly 2.8 outages per year with a duration of 7.5 hours average). The primary cause of the outages is faults on a long 55 kV transmission line that serves the town of Glacier from the Kendall substation. This approximately 10-mile long line is shown in the upper left of Figure 1 below. The Kendall-Glacier transmission line extends through an area of heavy forest with few reasonable options for increasing the line’s reliability. The substation in Glacier (also shown on figure below) serves over 1000 customers that are mostly residential but includes over 50 small businesses. The town has approximately 250 year-round residents, and a peak in visitors during the winter ski season when storms are also more likely to cause power outages. Figure 1: Proposed Microgrid in Glacier, WA Given the reliability challenges in Glacier, PSE is assessing the feasibility of a 2MW/4.4MWh battery energy storage system (BESS) that would allow for improved reliability. The BESS would also allow for the ability to investigate other applications for utility-scale energy 5 storage. This energy storage system is being considered for operation in “planned islanding” and “microgrid” mode. “Planned islanding” indicates use of the BESS to provide power to part or potentially all of the load in the town of Glacier during an outage. “Microgrid” indicates utilization (during an outage) of the BESS in parallel with Nooksack Falls Hydroelectric Power Plant, a small (nameplate 1.5 MW/2000 HP) hydro power plant less than 10 miles from the town of Glacier. Nooksack is a run-of river small hydro generation plant with a gross head of 226 ft. The site has a 5-foot diameter penstock which enters the powerhouse and goes into a pelton turbine with six runners on one shaft. It was originally constructed by Stone & Webster in 1906, which makes it the second oldest operating power generation facility in Western Washington. It was placed on the National Register of Historic places in December of 1988. The plant operated until 1997 when a fire destroyed the generator. The project continued operations in 2003 after the replacement of the generator and other updates.

13 HYDRO ENERGY↗

A High-resolution Regional Wave Resource Characterization For The U.S. West Coast

Objectives/Scope: Wave resource characterization is a critical step for wave energy converter deployment in the coastal ocean and relies on long-term, high-resolution wave datasets. This study presents a detailed modeling study of the wave resource along the U.S. West Coast (Washington, Oregon, and California), a coastal region that was identified with high wave energy potential in earlier studies. Methods, Procedures, Process: The wave hindcast covers a 32-year period from 1979 to 2010 and is based on a multi-resolution, unstructured-grid SWAN model framework. Model configuration closely follows and meets the requirements recommended by the International Electrotechnical Commission Technical Specification (IEC TS) for wave energy resource assessment and characterization (Class 2 - feasibility study). The model domain covers the entire U.S. Exclusive Economic Zone (EEZ) in the West Coast and has a spatial resolution varying from ~300 m in the nearshore region (20 km from the shoreline) to ~2500 m within the EEZ and ~5000 m at the open boundary, which extends beyond the EEZ. The model was forced by hourly 2-D wave spectra produced by a two-way nested WaveWatch III model, which covers the global ocean domain and the broader U.S. West Coast region domain with spatial resolutions of 0.5 degree and 10 arc-minutes, respectively. Both wave models are forced by hourly, 0.5-degree wind forcing obtained from NCEP’s Climate Forecast System Reanalysis (CFSR) product. Results, Observations, Conclusions: The standard model output for the SWAN model includes 3-hourly output for the six IEC wave resource parameters (e.g., omnidirectional wave power) at each grid point and hourly 2-D spectra at more than 50 NDBC buoys. Extensive model validation was achieved by comparing the six model-predicted IEC parameters with those derived from field observations at representative NDBC buoys. The error statistics indicated the model’s satisfactory performance. Further analyses were conducted to systematically evaluate the temporal and spatial distributions of wave energy potential and wave climate along the U.S. West Coast. Results suggest that Washington and Oregon coasts have similar nearshore wave resource, which is significantly higher than resources in Southern California. Strong seasonal variations are also observed, e.g., high wave energy tends to occur in the winter months. In summary, this study produced the first high-resolution, comprehensive dataset on wave energy distribution along the U.S. West Coast. Novel/Additive Information: The results are being used by the National Renewable Energy Laboratory to update the MHK Atlas, which was originally derived from NOAA’s 4-arc-minute WaveWatch III model output. In addition, the monthly averaged wave energy climatology dataset can be readily shared to support a variety of research and application efforts within the EEZ of the U.S. West Coast.

Wang, Taiping↗

Making Data-Driven Policy Decisions for the Nation’s First Building Energy Performance Standards

Nearly every major U.S. city has committed itself to ambitious climate action goals – for Washington, DC this means a 50 percent reduction in greenhouse gases by 2032 and carbon neutrality by 2050. In support of these goals, Washington, DC has passed one of the most aggressive and practical climate action bills in the nation—with the Clean Energy DC Omnibus Act, DC became the first city in the U.S. to adopt energy performance standards for existing buildings. DC’s Building Energy Performance Standards (BEPS) require energy efficiency improvements for all commercial and multifamily buildings that do not meet a sector-specific minimum ENERGY STAR score or equivalent metric, with iterative compliance cycles every five years that will accelerate the pace of whole building retrofits. This paper explores this revolutionary policy framework and uses two data analysis projects that DC conducted to evaluate the potential impact of the BEPS and move towards carbon neutrality. First, we analyze the potential energy savings and greenhouse gas reductions, as well as potential cost impacts, from the implementation of a BEPS policy in DC We then examine the role of BEPS in a carbon neutrality strategy, how BEPS savings iterate over time, and what additional existing building improvements will be driven by the gravitational pull of new building codes on median performance. The paper highlights the benefits and limitations of such data-driven approaches to support policy decisions. Finally, we will review ongoing BEPS implementation, including expected policy directions, critical supportive programs, and lessons learned to date.

Bergfeld, Katie↗

Geographically Dependent Sustainability Indicators for Comparison of Conventional Vegetable Production to Controlled-Environment Agriculture

Many food system lifecycle analyses distill agricultural production and supply chain impacts into single-value sustainability metrics for various food categories. These studies provide an overview of the food supply system that highlight striking results such as the GHG impacts of meat production. The supply chain impacts of vegetable production occupy the middle ground; higher than average food loss and waste, lower than average overall energy use, etc. However, aggregated results obscure the sustainability implications of the location of food production, especially for vegetables. Moreover, the increasing instability of food production systems are not captured, as illustrated by a recent Washington Post article. According to a UC Merced study conducted for the state, California farmers left nearly 400,000 acres of agricultural land unplanted last year because of a lack of water. The result, the study found, was a direct economic cost to farmers of $1.1 billion and the loss of nearly 9,000 agricultural jobs. (The Washington Post, March 21, 2022.) Previous work quantified the food-energy-water nexus implications of transitioning vegetable production from large, centralized agricultural operations to smaller distributed production in controlled-environment farms (CEA). The importance of location-specific data is especially evident for water use. Water impacts of the food system are primarily local to the region where food is produced, water impacts vary significantly between locations, and water stress is a major concern in locations that currently host large agricultural operations. Location-specific data is needed to accurately assess the water impacts of transitioning to CEA. The location of farms in relation to consumers impacts transportation energy use, food loss and waste, and requirements for food processing (e.g., to reduce weight, preserve foods for long storage, and package foods to reduce damage and loss) Reducing transport is particularly relevant for agricultural products that could be grown in CEAs (fruits, vegetables, protein). Access to nutritious food is not evenly distributed in the population. Remote communities, communities in harsh environments, and economically-disadvantaged communities often have poor access to healthy foods. CEA is ideally suited to these environments. However, the energy and water use of CEA, while in many respects lower overall than conventional supply chains, are concentrated within communities and could have significant local impacts. This paper reports on development of sustainability metrics that seek to capture the tradeoffs between the current supply chain and a CEA supply chain for vegetables; focusing on the location-dependent implications of water use, the transition from largely fossil fuel based energy use to electricity, and the food access, resilience and wellbeing implications of urban versus rural food production.

controlled-environment agriculture↗

Results from Laboratory and Field Study of Thin Triple Pane Windows

Heat transfer through windows accounts for a significant percentage of a building’s energy use and adds substantially to the peak cooling load of a home. In recent years, improvements in glass manufacturing have enabled the use of a very thin central pane of glass similar to a cell phone screen to produce a thin triple-pane window, for finished insulated glass units (IGUs) with an overall thickness similar to standard double-pane windows. Because this highly insulating “thin triple” glass product can be incorporated into almost any existing window frame and can be fabricated at a modest added cost, the U.S. Department of Energy sponsored laboratory and field demonstration testing of thin triple-pane windows to validate thermal performance and installation requirements in real-life field settings. Thin triple pane windows were evaluated at the PNNL Lab Homes, a matched pair of manufactured houses located on PNNL’s campus in Richland, Washington and also at 16 different field study sites around the country. The experimental results include a comparison of heating, ventilation, and air-conditioning (HVAC) energy usage, condensation potential, occupant comfort, sound infiltration, and thermal performance. Field study data will be gathered through June of 2022; preliminary results are being shared in this paper. The lab houses are identical except that the reference house had standard double pane windows with assembly U-0.66 and the test house had thin triple pane windows with assembly U-0.19. Across the experimental test days, the daily HVAC savings ranged from 0.2 to 18.7 kWh (3%–18%) for the heating season and from 2.5 to 8.0 kWh (23%–41%) for the cooling season. The higher thermal performance of the thin triple-pane windows also reduced the condensation potential on the interior surface during winter months and provided more even distribution of temperatures throughout the home in comparison to the baseline. In addition to the added thermal performance, the thin triple-pane windows demonstrated significant acoustic benefits, reducing sound infiltration by 8 dB to 10 dB. For the field test portion of the project thin triple pane insulated glass units were produced by two different manufacturers, and then installed without modification into the ½” IGU pockets of the standard double pane frames of four other manufacturers. Field tests performed on existing homes in Washington, Montana, Colorado, and New York compared thin triple pane retrofits to original window conditions (before and after). Field tests at new construction sites in Minnesota, Michigan, and New York compared thin triple pane windows to commercially available solutions such as double pane or traditional triple pane (with a standard-thickness center pane). Field test work is ongoing, but preliminary results appear to follow the sound, surface temperature, and energy improvement results from the Lab Homes comparison. Additionally, reports from builders and installers indicate that thin triples require almost no added time or effort to install and look nearly identical to other windows, indicating the possibility of offering next-level performance with a product that requires very little modification to current production or installation practices, long considered a major barrier to technology uptake in the construction market.

energy efficiency, home retrofit, Windows, window ↗

Improved Management of the Technical Interfaces Between the Hanford Tank Farm Operator and the Hanford Waste Treatment Plant - 13383

The Department of Energy (DOE) is constructing the Waste Treatment and Immobilization Plant (WTP) at the Hanford site in Washington to treat and immobilize approximately 114 million gallons of high level radioactive waste (after all retrievals are accomplished). In order for the WTP to be designed and operated successfully, close coordination between the WTP engineering, procurement, and construction contractor, Bechtel National, Inc. and the tank farms operating contractor (TOC), Washington River Protection Solutions, LLC, is necessary. To develop optimal solutions for DOE and for the treatment of the waste, it is important to deal with the fact that two different prime contractors, with somewhat differing contracts, are tasked with retrieving and delivering the waste and for treating and immobilizing that waste. The WTP and the TOC have over the years cooperated to manage the technical interface. To manage what is becoming a much more complicated interface as the WTP design progresses and new technical issues have been identified, an organizational change was made by WTP and TOC in November of 2011. This organizational change created a co-located integrated project team (IPT) to deal with mutual and interface issues. The Technical Organization within the One System IPT includes employees from both TOC and WTP. This team has worked on a variety of technical issues of mutual interest and concern. Technical issues currently being addressed include: - The waste acceptance criteria; - Waste feed delivery and the associated data quality objectives (DQO); - Evaluation of the effects of performing a riser cut on a single shell tank on WTP operations; - The disposition of secondary waste from both TOC and WTP; - The close coordination of the TOC double shell tank mixing and sampling program and the Large Scale Integrated Test (LSIT) program for pulse jet mixers at WTP along with the associated responses to the Defense Nuclear Facilities Safety Board (DNFSB) Recommendation 2010-2; - Development of a set of alternatives to the current baseline that involve aspects of direct feed, feed conditioning, and design changes. The One System Technical Organization has served WTP, TOC, and DOE well in managing and resolving issues at the interface. This paper describes the organizational structure used to improve the interface and several examples of technical interface issues that have been successfully addressed by the new organization. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

NRC Perspectives on Waste Incidental to Reprocessing Consultations and Monitoring - 13398

Section 3116 of the Ronald W. Reagan National Defense Authorization Act for Fiscal Year 2005 (NDAA) requires the U.S. Department of Energy (DOE) to consult with the U.S. Nuclear Regulatory Commission (NRC) for certain non-high level waste (HLW) determinations. The NDAA also requires NRC to monitor DOE's disposal actions related to those determinations to assess compliance with NRC regulations in 10 CFR Part 61, Subpart C. The NDAA applies to DOE activities that will remain within the States of South Carolina and Idaho. DOE has chosen to, under DOE Order 435.1, engage in consultation with NRC for similar activities in the State of Washington and New York, however, the NRC has no monitoring responsibilities. In 2007, the NRC developed a draft Final Report for Interim Use entitled, NUREG-1854: NRC Staff Guidance for Activities Related to U.S. Department of Energy Waste Determinations. Since the law was enacted, the DOE and NRC have consulted on three waste determinations within the affected States: (1) the Saltstone Disposal Facility at the Savannah River Site (SRS) within the State of South Carolina in 2005, (2) the INTEC Tank Farm at the Idaho National Laboratory within the State of Idaho in 2006, and (3) the F Tank Farm at SRS in 2011. After the end of consultation and issuance by DOE of the final waste determination, monitoring began at each of these sites, including the development of monitoring plans. In addition to the NDAA sites, DOE has requested NRC consultation support on both individual tanks and the entire C Tank Farm at the Hanford Nuclear Reservation in the State of Washington. DOE also requested consultation of waste determinations performed on the melter and related feed tanks at the West Valley site in New York that would be disposed offsite. In the next few years, NRC and DOE will consult on the last of the NDAA waste determinations for a while, the H Tank Farm waste determination at SRS. DOE may identify other activities in the future but largely NRC's role will change from doing both consultation and monitoring to being focused on monitoring activities within NDAA. DOE has identified other activities at the Hanford Nuclear Reservation that would continue consultation activities but outside of the NDAA in the future. During the past seven years of consultations and monitoring a number of lessons learned about the process, communication issues, and technical guidance have been identified. With the change in focus from reviewing initial performance assessments and draft waste determinations to long-term monitoring (e.g., individual waste tank closure, at F Tank Farm or complete tank farm closure at INTEC expected in the near future), the NRC is going to revise and update its guidance over the next few years to reflect the lessons learned and the change in focus. In addition to the lessons learned, improvements in the guidance will have to account possible rule and guidance changes underway within Part 61. This paper will discuss the initial plans, approaches, and time lines to revise the guidance within NUREG-1854, including opportunities for public involvement. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

How the Lean Management System is Working on a Closure Project - 13242

Washington Closure Hanford, LLC (WCH) manages the River Corridor Closure Project (RCCP), a 10-year contract, in which WCH will clean up 220 mi{sup 2} of contaminated land at the Hanford Site in Richland, Washington. Strategic planning sessions in 2009 identified key performance areas that were essential to closure and in which focused change could result in dramatic performance improvement. Lean Management Systems (Lean) was selected as the methodology to achieve the desired results. The Lean Process is built upon the fundamentals of the power of respect for people and the practice of continuous process improvement. Lean uses week-long, focused sessions that teach a selected team the techniques to recognize waste within their own work processes, propose potential solutions, and then conduct experiments during the week to test their solutions. In 2011, the Lean process was implemented in the Waste Operations organization. From there it was expanded to closure documents, field remediation, and decommissioning and demolition. WCH identified the following Lean focus areas: 1) closure document processes that required extensive internal preparation, and lengthy external review and approval cycles; 2) allocation of limited transportation and waste disposal resources to meet aggressive remediation schedules; 3) effective start-of-the-day routines in field operations; 4) improved excavation and load-out processes; and 5) approaches to strengthen safety culture and support disciplined operations. Since the introduction of Lean, RCCP has realized many successes and also gained some unexpected benefits. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Observational Approach to Chromium Site Remediation - 13266

Production reactors at the U.S. Department of Energy's (DOE) Hanford Site in Richland, Washington, required massive quantities of water for reactor cooling and material processing. To reduce corrosion and the build-up of scale in pipelines and cooling systems, sodium dichromate was added to the water feedstock. Spills and other releases at the makeup facilities, as well as leaks from miles of pipelines, have led to numerous areas with chromium-contaminated soil and groundwater, threatening fish populations in the nearby Columbia River. Pump-and-treat systems have been installed to remove chromium from the groundwater, but significant contamination remain in the soil column and poses a continuing threat to groundwater and the Columbia River. Washington Closure Hanford, DOE, and regulators are working on a team approach that implements the observational approach, a strategy for effectively dealing with the uncertainties inherent in subsurface conditions. Remediation of large, complex waste sites at a federal facility is a daunting effort. It is particularly difficult to perform the work in an environment of rapid response to changing field and contamination conditions. The observational approach, developed by geotechnical engineers to accommodate the inherent uncertainties in subsurface conditions, is a powerful and appropriate method for site remediation. It offers a structured means of quickly moving into full remediation and responding to the variations and changing conditions inherent in waste site cleanups. A number of significant factors, however, complicate the application of the observational approach for chromium site remediation. Conceptual models of contamination and site conditions are difficult to establish and get consensus on. Mid-stream revisions to the design of large excavations are time-consuming and costly. And regulatory constraints and contract performance incentives can be impediments to the flexible responses required under the observational approach. The WCH project team is working closely with stakeholders and taking a number of steps to meet these challenges in a continuing effort to remediate chromium contaminated soil in an efficient and cost-effective manner. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Modeling and Analysis of Coupled Flow Through Packed Beds as a Diagnostic Tool for Packed Bed Reactor Health - 17172

The US Department of Energy, Office of River Protection, is building the Waste Treatment and Immobilization Plant (WTP) in Richland, Washington, to immobilize the hundreds of millions of liters of radioactive waste stored at the Hanford Site in Washington state. The offgas generated during vitrification of these wastes requires treatment to remove and/or destroy chemical and radioactive hazardous components before release to the atmosphere. In particular, volatile and semi-volatile hydrocarbon components are to be catalytically oxidized to carbon dioxide and water, whereas nitrogen oxides (NOx) are to be catalytically reduced to nitrogen and water. These tasks are accomplished in a series of packed bed reactors. Achieving the requisite Destruction/Removal Efficiency (DRE) for each of the tracked components is highly dependent on the flow characteristics of the offgas through the packed beds. The flow kinetics may be monitored and characterized during the initial warm-up of the system. The gases, initially at 76 deg. C (169 deg. F), (a) flow through one side of a countercurrent heat exchanger to recover heat from the exiting gases (which have already passed through the catalytic beds), (b) are then further heated electrically to approximately 400 deg. C (750 deg. F; the preferred operating temperature of the Thermo Catalytic Oxidizer (TCO)), (c) pass through the TCO where the reduced components of the offgas are oxidized over a supported Pt catalyst bed, (d) are partially cooled to approximately 315 deg. C (600 deg. F) by addition of approximately 25% (by weight) diluted ammonia/air mixture, (e) pass through the Selective Catalytic Reducer (SCR) where the NOx components are converted to N{sub 2} and H{sub 2}O over a supported V2O{sub 5}/TiO{sub 2} catalyst bed, and (f) exit through the hot side of the countercurrent heat exchanger. The electrical heater is not powerful enough to raise the temperature of the offgas to the desired 400 deg. C without the contribution of the heat recovered in the heat exchanger. Moreover, the thermal mass of the beds and housings of the TCO and SCR require a significant input of thermal energy to reach the desired operating temperatures; the better part of a day is required to bring the unit from ambient temperatures to operating temperatures. Therefore, the temperature of the stream during the initial warm-up of the system at each point in the system is dependent upon the thermal mass, flow dispersion, and permeability of the components, quantified as characteristic/representative volumes and residence times. By monitoring the temperature of the offgas as it enters and exits each portion of the system during this warm-up period one may model the system as a series of small Continuously Stirred Tank Reactors (CSTR)s (referred to as 'CSTRlets') to explain the flow kinetics through the catalyst beds. These component CSTRlets are adjustable in size and number, that one may model the flow profile of the gases through the catalyst beds. For example, a single large CSTR will present an effluent temperature profile with a simple exponential decay shape. Concatenating more CSTRlets generate more complex sigmoidal responses. Concatenating one CSTRlet significantly larger than the others in the train also alters the shape of the effluent temperature profile, in a fashion not replicable by a train of equal-sized CSTRlets. The ultimate goal is to accurately emulate the entire system as a representative CSTRlet train. Once accomplished, this characterization may be used in subsequent warm-ups (following shutdown for catalyst maintenance, for example) or by an intentional step change in inlet offgas temperature to detect/diagnose anomalies in flow through the beds (e.g., channeling or partial blockage.) This work presents development of this model through analytical, calculational, and empirical means. - The analytic model is accomplished by Laplace transform analysis of each component to recover component process transfer functions. - The calculational portion is performed via brute force finite element calculation. - Fitting empirical data from the warm-up of the TCO skid allows one to select the hypothetical CSTRlet trains which best fit the TCO and SCR beds for the analytical and finite element calculations. The first portion of this paper presents the development of the analytical (Laplace space) model of the coupled system. Estimated values for the initial temperature, mass, specific heat, electrical heat, and relative quantities of the offgas, catalyst beds, stainless steel housings, and ammonia dilution stream are used to generate expected temperature profiles at several selected junctures of the system. The number and size of the component hypothetical CSTRlets are calculated from the analytical model and are used to predict temperature profiles at the exit of the system and at intermediate junctions between system components (where thermocouples are present in the actual unit.) The finite element calculations employ a series of CSTRlet volumes to produce a similar suite of temperature profiles, for comparison with the analytical model results. Finally, empirical data from the Factory Acceptance Test system warm-up are used to select and compare the results from each modeling strategy to select the CSTRlet train(s) which best model the behavior of the actual system. This work presents a novel method of system component characterization, of value to the WTP plant and similar vitrification facilities as well as chemical process industries unrelated to waste management. (authors)

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Remediation of 130 mSv/hr. Soil Contamination Under a Hot Cell - 17301

Department of Energy (DOE) contractor CH2M HILL Plateau Remediation Company (CH2M) is currently engineering a system to safely remove and dispose of highly contaminated soil underneath Building 324 located adjacent to the Columbia River on the Hanford Site in Washington State. Cleaning up the waste site will allow for the eventual demolition of the building, which is a top priority for DOE and CH2M due to the proximity of the Columbia River and City of Richland. Building 324 at Hanford was originally constructed in 1966 and was operated for a number of years serving various missions. One of the missions involved development of treatment processes for liquid high activity waste. As of result of one particular mission, liquid high activity waste was spilled in one of the building's hot cells (known as 'B' Cell) and the liquid leaked from a breach in a sump and through construction joints in the hot cell floor and into the soil. Sampling efforts using borehole technology revealed significant under-building contamination with dose rates measuring has high as 130 mSv/hr (13,000 R/hr.). The Hanford Federal Facility Agreement and Consent Order (Tri-Party Agreement) between the Washington State, Department of Ecology (Ecology), the U.S. Environmental Protection Agency and the DOE has established a 2021 milestone for demolition and removal of the Building 324. Before building demolition can be undertaken, the highly contaminated soil must be removed from beneath the hot cell while the hot cell structure remains in place to provide shielding and containment during the soil remediation. CH2M will fabricate and install remotely operated equipment that will remove debris and grout in the cell, the floor of the hot cell, and the contaminated soil beneath the hot cell and package that soil for disposal. To ensure that the structure remains intact and does not shift during soil removal, support for the building structure must also be constructed as a prerequisite for the planned work. CH2M will use a full-scale mock-up of the Building 324 B Cell and airlock area to assist in the testing of the remotely operated equipment and the training of the soil removal team in a contamination-free environment to ensure efficient and safe performance of the challenging work of the project. (authors)

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