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At least 343 records · Page 19

WTP Modifications to Support DFLAW: LAW, BOF, Lab - 16219

The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is a one-of-a-kind nuclear waste treatment facility being designed and constructed for the U.S. Department of Energy by Bechtel National, Inc. and principal subcontractor URS to process and vitrify radioactive waste stored in underground tanks at the Hanford Site. The Tank Operations Contractor, Washington River Protection Solutions, has responsibility to retrieve, stage, pretreat, and deliver the tank waste feed to WTP. To treat tank waste as soon as practicable, a scenario is being considered to deliver pretreated feed straight to WTP's Low-Activity Waste (LAW) Vitrification Facility. This scenario is called the Direct Feed LAW (DFLAW) program. Balance of Facility utility and system facilities are designed for full WTP operation. Thirteen of these are needed to support reduced throughput during DFLAW operation, of which eight require moderate to extensive changes. Extensive changes include permanent plant modifications that allow DFLAW to operate if the Pretreatment (PT) Facility is unavailable. Under full WTP operation, effluents from the LAW Facility will be returned to the PT Facility for further processing and/or transfer to the Liquid Effluent Retention Facility/Effluent Treatment Facility. The PT Facility also handles all flush water from the tank farm transfers. To address these requirements, a Value Improvement Project was performed. The recommended approach is to provide a 'split stream' Effluent Management Facility (EMF) with an evaporator to support DFLAW. The required modifications for DFLAW facilities are discussed in this paper. (authors)

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Developing Waste-Driven Design Requirements for Filtration and Ion-Exchange at the Hanford LAWPS Facility - 16394

The United States Department of Energy is building the Low Activity Waste Pretreatment System (LAWPS) at the Hanford site near Richland, Washington to treat liquid tank waste. The primary unit operations are filtration for solids removal and ion-exchange for cesium-137 removal. The properties of the stored waste are diverse, therefore the design requirements need to allow for a variety of feeds from the Hanford tank farms. However, it is not cost effective to allow a few rare feeds to define the requirements when there are other options for treating the rare wastes. The waste-derived design requirements were based on trends from this data. The primary feed requirements that will drive filtration and ion-exchange performance are solids content of the feed, cesium to sodium ratio, and potassium concentration. Additionally, aluminum and total organic carbon (TOC) concentrations are considered for flammable gas generation. For the cesium and potassium concentrations, the available experimental data was collected, sorted, and compared against the historic requirements. The design basis for cesium and potassium feed parameters developed here enveloped all but a couple outlier tanks. A review of available grab sample data indicates that occasionally the samples would have up to 0.8 wt% solids concentration. One single sample had 3.3 wt% solids concentration. These solids concentrations were assigned as the nominal and upper bounding solids concentrations. Flammable gas generation does not directly impact the ion exchange process throughput but does impact the design safety requirements, thus TOC and aluminum concentrations (which are inputs to the flammable gas calculations) were examined in a similar way, but were paired together through a simplified correlation to reach an upper bounding value of 0.6 wt% TOC*Al{sup 0.4}. (authors)

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SRNL Phase 1 Assessment of the WTP Waste Qualification Program

The Hanford Tank Waste Treatment and Immobilization Plant (WTP) Project is currently transitioning its emphasis from an engineering design and construction phase toward facility completion, start-up and commissioning. With this transition, the WTP Project has initiated more detailed assessments of the requirements that must be met during the actual processing of the Hanford Site tank waste. One particular area of interest is the waste qualification program. In general, the waste qualification program involves testing and analysis to demonstrate compliance with waste acceptance criteria, determine waste processability, and demonstrate laboratory-scale unit operations to support WTP operations. The testing and analysis are driven by data quality objectives (DQO) requirements necessary for meeting waste acceptance criteria for transfer of high-level wastes from the tank farms to the WTP, and for ensuring waste processability including proper glass formulations during processing within the WTP complex. Given the successful implementation of similar waste qualification efforts at the Savannah River Site (SRS) which were based on critical technical support and guidance from the Savannah River National Laboratory (SRNL), WTP requested subject matter experts (SMEs) from SRNL to support a technology exchange with respect to waste qualification programs in which a critical review of the WTP program could be initiated and lessons learned could be shared. The technology exchange was held on July 18-20, 2011 in Richland, Washington, and was the initial step in a multi-phased approach to support development and implementation of a successful waste qualification program at the WTP. The 3-day workshop was hosted by WTP with representatives from the Tank Operations Contractor (TOC) and SRNL in attendance as well as representatives from the US DOE Office of River Protection (ORP) and the Defense Nuclear Facility Safety Board (DNFSB) Site Representative office. The purpose of the workshop was to share lessons learned and provide a technology exchange to support development of a technically defensible waste qualification program. The objective of this report is to provide a review, from SRNL's perspective, of the WTP waste qualification program as presented during the workshop. In addition to SRNL's perspective on the general approach to the waste qualification program, more detailed insight into the specific unit operations presented by WTP during the workshop is provided. This report also provides a general overview of the SRS qualification program which serves as a basis for a comparison between the two programs. Recommendations regarding specific steps are made based on the review and SRNL's lessons learned from qualification of SRS low-activity waste (LAW) and high-level waste (HLW) to support maturation of the waste qualification program leading to WTP implementation.

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One System Integrated Project Team: Retrieval and Delivery of Hanford Tank Wastes for Vitrification in the Waste Treatment Plant - 13234

The One System Integrated Project Team (IPT) was formed in late 2011 as a way for improving the efficiency of delivery and treatment of highly radioactive waste stored in underground tanks at the U.S. Department of Energy's (DOE's) 586-square-mile Hanford Site in southeastern Washington State. The purpose of the One System IPT is to improve coordination and integration between the Hanford's Waste Treatment Plant (WTP) contractor and the Tank Operations Contractor (TOC). The vision statement is: One System is a WTP and TOC safety-conscious team that, through integrated management and implementation of risk-informed decision and mission-based solutions, will enable the earliest start of safe and efficient treatment of Hanford's tank waste, to protect the Columbia River, environment and public. The IPT is a formal collaboration between Bechtel National, Inc. (BNI), which manages design and construction of the WTP for the U.S. Department of Energy's Office of River Protection (DOEORP), and Washington River Protection Solutions (WRPS), which manages the TOC for ORP. More than fifty-six (56) million gallons of highly radioactive liquid waste are stored in one hundred seventy-seven (177) aging, underground tanks. Most of Hanford's waste tanks - one hundred forty-nine (149) of them - are of an old single-shell tank (SST) design built between 1944 and 1964. More than sixty (60) of these tanks have leaked in the past, releasing an estimated one million gallons of waste into the soil and threatening the nearby Columbia River. There are another twenty-eight (28) new double-shelled tanks (DSTs), built from 1968 to 1986, that provide greater protection to the environment. In 1989, DOE, the U.S. Environmental Protection Agency (EPA), and the Washington State Department of Ecology (Ecology) signed a landmark agreement that required Hanford to comply with federal and state environmental standards. It also paved the way for agreements that set deadlines for retrieving the tank wastes and for building and operating the WTP. The tank wastes are the result of Hanford's nearly fifty (50) years of plutonium production. In the intervening years, waste characteristics have been increasingly better understood. However, waste characteristics that are uncertain and will remain as such represent a significant technical challenge in terms of retrieval, transport, and treatment, as well as for design and construction of WTP. What also is clear is that the longer the waste remains in the tanks, the greater the risk to the environment and the people of the Pacific Northwest. The goal of both projects - tank operations and waste treatment - is to diminish the risks posed by the waste in the tanks at the earliest possible date. About two hundred (200) WTP and TOC employees comprise the IPT. Individual work groups within One System include Technical, Project Integration and Controls, Front-End Design and Project Definition, Commissioning, Nuclear Safety and Engineering Systems Integration, and Environmental Safety and Health and Quality Assurance (ESH and QA). Additional functions and team members will be added as the WTP approaches the operational phase. The team has undertaken several initiatives since its formation to collaborate on issues: (1) alternate scenarios for delivery of wastes from the tank farms to WTP; (2) improvements in managing Interface Control Documents; (3) coordination on various technical issues, including the Defense Nuclear Facilities Nuclear Safety Board's Recommendation 2010-2; (4) deployment of the SmartPlant{sup R} Foundation-Configuration Management System; and (5) preparation of the joint contract deliverable of the Operational Readiness Support Plan. (authors)

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Overview and History of DOE's Hanford Site - 12502

Hanford's DOE offices are responsible for one of the largest nuclear cleanup efforts in the world, cleaning up the legacy of nearly five decades of nuclear weapons production. Nowhere in the DOE Complex is cleanup more challenging than at the Hanford Site in southeastern Washington. Hanford cleanup entails remediation of hundreds of large complex hazardous waste sites; disposition of nine production reactors and the preservation of one as a National Historic Landmark; demolition of hundreds of contaminated facilities including five enormous process canyons; remediation of billions of gallons of contaminated groundwater; disposition of millions of tons of low-level, mixed low-level, and transuranic waste; disposition of significant quantities of special nuclear material; storage and ultimate disposition of irradiated nuclear fuel; remediation of contamination deep in the soil that could impact groundwater; decontamination and decommissioning of hundreds of buildings and structures; and treatment of 56 million gallons of radioactive waste in 177 large underground tanks through the construction of a first-of-its-kind Waste Treatment Plant. Cleanup of the Hanford Site is a complex and challenging undertaking. The DOE Richland Operations Office has a vision and a strategy for completing Hanford's cleanup including the transition to post-cleanup activities. Information on the strategy is outlined in the Hanford Site Completion Framework. The framework describes three major components of cleanup - River Corridor, Central Plateau, and Tank Waste. It provides the context for individual cleanup actions by describing the key challenges and approaches for the decisions needed to complete cleanup. The U.S. Department of Energy (DOE), as regulated by the U.S. Environmental Protection Agency (EPA) and Washington State Department of Ecology (Ecology), is implementing a strategy to achieve final cleanup decisions for the River Corridor portion of the Hanford Site. The DOE Richland Operations Office (RL) and DOE Office of River Protection (ORP) have prepared this document to describe the strategy and to begin developing the approach for making cleanup decisions for the remainder of the Hanford Site. DOE's intent is that the Completion Framework document will facilitate dialogue among the Tri-Parties and with Hanford's diverse interest groups, including Tribal Nations, State of Oregon, Hanford Advisory Board, Natural Resource Trustees, and the public. Future cleanup decisions will be enhanced by an improved understanding of the challenges facing cleanup and a common understanding of the goals and approaches for cleanup completion. The overarching goals for cleanup are sevenfold. - Goal 1: Protect the Columbia River. - Goal 2: Restore groundwater to its beneficial use to protect human health, the environment, and the Columbia River. - Goal 3: Clean up River Corridor waste sites and facilities to: Protect groundwater and the Columbia River. Shrink the active cleanup footprint to the Central Plateau, and support anticipated future uses of the land. - Goal 4: Clean up Central Plateau waste sites, tank farms, and facilities to: Protect groundwater. Minimize the footprint of areas requiring long-term waste management activities. Support anticipated future uses of the land. - Goal 5: Safely manage and transfer legacy materials scheduled for off-site disposition including special nuclear material (including plutonium), spent nuclear fuel, transuranic waste, and immobilized high-level waste. - Goal 6: Consolidate waste treatment, storage, and disposal operations on the Central Plateau. - Goal 7: Develop and implement institutional controls and long-term stewardship activities that protect human health, the environment, and Hanford's unique cultural, historical and ecological resources after cleanup activities are completed. These goals embody more than 20 years of dialogue among the Tri-Party Agencies, Tribal Nations, State of Oregon, stakeholders, and the public. They carry forward key values captured in forums such as the Hanford Future Site Uses Working Group, Tank Waste Task Force, Hanford Summits, and Hanford Advisory Board Exposure Scenario Workshops, as well as more than 200 advice letters issued by the Hanford Advisory Board (http://www.hanford.gov/page.cfm/hab). These goals help guide all aspects of Hanford Site cleanup. Cleanup activities at various areas of the site support the achievement of one or more of these goals. These goals help set priorities to apply resources and sequence cleanup efforts for the greatest benefit. These goals reflect DOE's recognition that the Columbia River is a critical resource for the people and ecology of the Pacific Northwest. The 50-mile stretch of the river known as the Hanford Reach is home to the last free-flowing section of the river in the U.S. As one of the largest rivers in North America, its waters support a multitude of uses that are vital to the economic and environmental well being of the region and it is particularly important in sustaining the culture of Native Americans. Cleanup actions must protect this river. (authors)

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Statistical Methods and Tools for Hanford Staged Feed Tank Sampling

This report summarizes work conducted by Pacific Northwest National Laboratory to technically evaluate the current approach to staged feed sampling of high-level waste (HLW) sludge to meet waste acceptance criteria (WAC) for transfer from tank farms to the Hanford Waste Treatment and Immobilization Plant (WTP). The current sampling and analysis approach is detailed in the document titled Initial Data Quality Objectives for WTP Feed Acceptance Criteria, 24590-WTP-RPT-MGT-11-014, Revision 0 (Arakali et al. 2011). The goal of this current work is to evaluate and provide recommendations to support a defensible, technical and statistical basis for the staged feed sampling approach that meets WAC data quality objectives (DQOs).

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NRC Consultation and Monitoring at the Savannah River Site: Focusing Reviews of Two Different Disposal Actions - 12181

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 determinations. The NDAA also requires NRC to monitor DOE's disposal actions related to those determinations. In Fiscal Year 2011, the NRC staff reviewed DOE performance assessments for tank closure at the F-Tank Farm (FTF) Facility and salt waste disposal at the Saltstone Disposal Facility (SDF) at the Savannah River Site (SRS) as part of consultation and monitoring, respectively. Differences in inventories, waste forms, and key barriers led to different areas of focus in the NRC reviews of these two activities at the SRS. Because of the key role of chemically reducing grouts in both applications, the evaluation of chemical barriers was significant to both reviews. However, radionuclide solubility in precipitated metal oxides is expected to play a significant role in FTF performance whereas release of several key radionuclides from the SDF is controlled by sorption or precipitation within the cementitious wasteform itself. Similarly, both reviews included an evaluation of physical barriers to flow, but differences in the physical configurations of the waste led to differences in the reviews. For example, NRC's review of the FTF focused on the modeled degradation of carbon steel tank liners while the staff's review of the SDF performance included a detailed evaluation of the physical degradation of the saltstone wasteform and infiltration-limiting closure cap. Because of the long time periods considered (i.e., tens of thousands of years), the NRC reviews of both facilities included detailed evaluation of the engineered chemical and physical barriers. The NRC staff reviews of residual waste disposal in the FTF and salt waste disposal in the SDF focused on physical barriers to flow and chemical barriers to radionuclide release from the waste. Because the waste inventory and concentration at both sites is sufficient to generate unacceptable doses to an off-site member of the public or inadvertent intruder in the absence of engineered barriers, the NRC staff review focused on the engineering features DOE plans to put in place to limit radionuclide release. At the FTF, DOE expects that peak doses are delayed beyond a 10,000 year performance period by a combination of (1) the flow-limiting effect of the steel tank liner and (2) chemical conditions created by the stabilizing grout overlying the waste that limit the solubility of key radionuclides for tens of thousands of years. At the SDF, DOE expects that flow will be significantly limited by water shedding along the closure cap lower drainage layer and that radionuclide release will be further limited by radionuclide precipitation or sorption within the high pH, chemically reducing conditions created within the saltstone waste form. Because the performance of both facilities depends on the performance of engineered barriers for thousands of years, the reviews included a detailed evaluation of the expected long-term behavior of these barriers. As previously discussed, NRC staff reviews of DOE waste determinations during consultation are designed to evaluate the three NDAA criteria, whereas the review of an updated PA during monitoring only addresses whether the NRC staff has reasonable assurance that the planned disposal action will meet the performance objectives of 10 CFR Part 61. The NRC staff review of the Waste Determination for the FTF did not include conclusions about whether the planned disposal of residual waste at the FTF would meet the NDAA criteria because of the substantial uncertainties in the degree of waste removal DOE would achieve and other technical uncertainties. The main product of the NRC staff review of the planned FTF disposal action is the recommendation that DOE should conduct waste release experiments to increase support for key modeling assumptions related to: (1) the evolution of pH and Eh in the grouted tank system over time; (2) identification of HRR association with solid phases comprising the residual wastes; and (3) expected solubility of HRRs under a range of environmental or service conditions that the residual wastes in the contaminated zone are expected to be exposed to over time. Implementation of this recommendation is deemed crucial for NRC staff to have reasonable assurance that the performance objectives in 10 CFR Part 61, Subpart C can be met. Given the risk-significance of Tank 18 to the overall PA and the short timeline for closure of this tank, the NRC staff recommended that DOE should initiate discussions with NRC staff regarding implementation of this recommendation for Tank 18 as soon as practical. The NRC staff also recommended that experiments to address this recommendation should be conducted prior to final closure of Tank 18. Results of the Tank 18 residual waste experiments, if conducted, will be evaluated by NRC staff to determine the need for additional data collection, experiments, and modeling for Tank 18, as well as other FTF tanks. Additional information regarding the NRC staff's recommendations in this area, including details on the suggested implementation of other recommendations will be provided in the NRC staff's plan for monitoring the FTF later in FY 2012, after DOE makes a final decision on the waste determination. The NRC staff's review of waste disposal at the SDF is ongoing. When complete, the SDF TER will indicate whether the NRC staff continues to have reasonable assurance that waste disposal at the SDF will meet the performance objectives of 10 CFR Part 61 (NDAA Criterion 3). The TER also will include risk insights that will form the basis of the NRC staff's revised monitoring plan for the SDF. The NRC staff will publish an updated monitoring plan for the SDF later in FY 2012. (authors)

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Improved Heat Exchanger Performance Achieved Through Improved Condensate Drainage - 18478

Hanford's 242-A Evaporator has had the mission of reducing waste volume in the Hanford Tank Farms since the late 1970's. At the very heart of the 242-A evaporation process is the E-A-1 reboiler, a heat exchanger which adds heat to the waste, and the vacuum condenser system, a three-stage condenser/ejector system which condenses the waste vapors and provides the vacuum at which the evaporation process operates. Over a long period of time, significant degraded performance has been observed in the heat exchangers in both the heating system and in the vacuum condensing system. This degraded performance was indicative of degraded conditions in equipment and/or piping associated with both the heating and vacuum condenser systems. However, in searching for degraded condition in these systems, 242-A engineering also discovered that both systems contained design errors in the condensate drainage associated with all heat exchangers in both systems. By addressing the condensate design errors in addition to correcting the degraded conditions, system performance was restored and even possibly improved. All heat exchangers in the heating and vacuum condensing systems are shell and tube type heat exchangers. Both have liquid on the tube side and vapor on the shell side (in the case of the reboiler the liquid is tank waste and the vapor is 10 lb heating steam, and in the case of the vacuum condensers the liquid is cooling water and the vapor is waste vapor). In both systems, engineering proposed that the vapor condensate was backing up into the heat exchanger, resulting in added poor performance. By focusing on basic heat exchanger system design, projects were initiated to redesign the condensate drainage of these systems and re-plumb the condensate drain lines. Data collected before and after the replumbing provides evidence that the corrected drain lines from the heat exchangers improved the performance of the system as a whole, and in the case of the reboiler, removed a potentially damaging steam condensate water hammer condition. (author)

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Strong-Sludge Gas Retention and Release Mechanisms in Clay Simulants

The Hanford Site has 28 double-shell tanks (DSTs) and 149 single-shell tanks (SSTs) containing radioactive wastes that are complex mixes of radioactive and chemical products. The mission of the Department of Energy's River Protection Project is to retrieve and treat the Hanford tank waste for disposal and close the tank farms. A key aspect of the mission is to retrieve and transfer waste from the SSTs, which are at greater risk for leaking, into DSTs for interim storage until the waste is transferred to and treated in the Waste Treatment and Immobilization Plant. There is, however, limited space in the existing DSTs to accept waste transfers from the SSTs, and approaches to overcoming the limited DST space will benefit the overall mission. The purpose of this study is to summarize and analyze the key previous experiment that forms the basis for the relaxed controls and to summarize progress and results on new experiments focused on understanding the conditions that result in low gas retention. The previous large-scale test used about 50 m3 of sediment, which would be unwieldy for doing multiple parametric experiments. Accordingly, experiments began with smaller-scale tests to determine whether the desired mechanisms can be studied without the difficulty of conducting very large experiments. The most significant results from the current experiments are that progressively lower gas retention occurs in tests with progressively deeper sediment layers and that the method of gas generation also affects the maximum retention. Based on the results of this study, it is plausible that relatively low gas retention could occur in sufficiently deep tank waste in DSTs. The current studies and previous work, however, have not explored how gas retention and release will behave when two or more layers with different properties are present.

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Analysis in Support of Disposition of Tank 48 Legacy Material

This report contains the characterization of six 200-mL Tank 48H samples: HTF-48-21-74, HTF-48-21-75, HTF-48-21-76, HTF-48-21-81, HTF-48-21-82, and HTF-48-21-83. The effort supports a Systems Engineering Evaluation (SEE) recommendation involving a Tank 48H decantation strategy that would remove liquid volume and grout the solids. The first three Tank 48H samples were surface samples taken after a quiescent period in the tank. The quiescent period allowed settling of the solids, these being mostly potassium tetraphenylborate. These three surface samples had no measurable solids, though a settling haze could be seen. The latter three samples were taken at 48, 25, and 10 inches from the bottom of Tank 48H immediately after tank mixing pumps had been run. Those samples contained measurable insoluble solids that were readily visible. All six samples were analyzed to provide chemical and radionuclide concentrations as defined as the "Limit" and "Target" in the Saltstone Production Facility (SPF) Waste Acceptance Criteria (WAC) and per the compliance strategy in the Tank Farm Waste Compliance Plan (WCP). Samples were analyzed by many methods to determine pH, density/specific gravity, radioactive isotopes, soluble and insoluble elements, total solids, total insoluble solids, organic and inorganic mercury, volatile and semi-volatile chemicals, and anions. Photographs of the settling of small samples were taken over time and are displayed in this report. The extent of settling was very significant, showing that surface sample liquids are similar to filtrates. However, Cs-137 measurements exceeded WAC limits in all surface samples (1.1E+07 vs. 1.3E+06). The solids were found to contain very high cesium activity, measured as high as 1.1E+10 dpm/gram. Sodium was in the range of 4.24 to 4.74 M for all samples, so the solids would tend to settle with time and would not be at risk of floating without air entrainment. No organic mercury was detected in this work.

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Analysis in Support of Disposition of Tank 48 Legacy Material

This report contains the characterization of six 200-mL Tank 48H samples: HTF-48-21-74, HTF-48-21-75, HTF-48-21-76, HTF-48-21-81, HTF-48-21-82, and HTF-48-21-83. The effort supports a Systems Engineering Evaluation (SEE) recommendation involving a Tank 48H decantation strategy that would remove liquid volume and grout the solids. The first three Tank 48H samples were surface samples taken after a quiescent period in the tank. The quiescent period allowed settling of the solids, these being mostly potassium tetraphenylborate. These three surface samples had no measurable solids, though a settling haze could be seen. The latter three samples were taken at 48, 25, and 10 inches from the bottom of Tank 48H immediately after tank mixing pumps had been run. Those samples contained measurable insoluble solids that were readily visible. All six samples were analyzed to provide chemical and radionuclide concentrations as defined as the "Limit" and "Target" in the Saltstone Production Facility (SPF) Waste Acceptance Criteria (WAC) and per the compliance strategy in the Tank Farm Waste Compliance Plan (WCP). Samples were analyzed by many methods to determine pH, density/specific gravity, radioactive isotopes, soluble and insoluble elements, total solids, total insoluble solids, organic and inorganic mercury, volatile and semi-volatile chemicals, and anions. Photographs of the settling of small samples were taken over time and are displayed in this report. The extent of settling was very significant, showing that surface sample liquids are similar to filtrates. However, Cs-137 measurements exceeded WAC limits in all surface samples (1.1E+07 vs. 1.3E+06). The solids were found to contain very high cesium activity, measured as high as 1.1E+10 dpm/gram. Sodium was in the range of 4.24 to 4.74 M for all samples, so the solids would tend to settle with time and would not be at risk of floating without air entrainment. No organic mercury was detected in this work.

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Technology Basis for Savannah River Tank Closure Cesium Removal Project - 17448

Westinghouse is currently executing a contract, awarded in June 2016 from Savannah River Remediation LLC, to deliver a system capable of removing solids and up to 100,000 curies of Cesium-137 from tank 10H, located in the Savannah River 'tank farm'. Savannah River Remediation currently has the responsibility to perform work for the Savannah River Site Liquid Waste Operations Program at the Savannah River Site for the US government, represented by the US DOE under their Principal contract. The scope of work covers the detailed design, procurement, fabrication, and delivery of the system to the Savannah River Site. It also includes the factory acceptance testing of the system, prior to delivery to site. Before leaving the site, Westinghouse will perform an evaluation of the system assembly and operations training for the incumbent operator. The basis for the technology chosen to accomplish the solids and Cesium-137 removal is unique to the specific feed stream, but is based on well-known and successful technology, Toshiba SARRY water cleanup system. Toshiba is Westinghouse's parent company, allowing us to reach back and incorporate the lessons learned during the water cleanup at Fukushima Daiichi and the integration of various technologies. Another key to the technology basis was the ion exchange media selection. A number of possible ion exchange media for the cesium removal were considered with the final choice being inorganic CST resin. Several criteria were considered and compared, such as the radiation sensitivity of the CST and the cesium specific ion preference. This paper will present the conceptual design of the modular system, noting the key benefits of specific components in the overall technology basis. Along with the design, a look at key technology improvements carried into the design through the Toshiba SARRY system will be incorporated. A first feedback on the implementation of the overall project will be provided. Since this system is a first-of-a-kind in this specific application, interesting lessons learned will be provided for future tank closure activities. (authors)

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WM26 Paper Multi-Robot Collaboration for Hazardous Environments

Hazardous nuclear and industrial facilities are rarely designed for robots. Work in these domains demand precise manipulation and robust mobility in cluttered, constrained spaces where off-the-shelf platforms struggle and “one-size-fits-all” machines become costly and complex. Idaho National Laboratory (INL) is developing an autonomous, multi-robot inspection system that coordinates task-specific platforms rather than relying on a single omni-tool robot. An electric truck serves as a power and compute hub for a custom manipulator co-developed with Florida International University (FIU), a commercial mini crawler, a pan–tilt–zoom camera, and a Nexxis Argus LiDAR mapping system. Working in concert, these robots generate spatial, radiation, and temperature maps of the pit environments at the Hanford Waste Tank Farms. These systems will capture visual records and environmental telemetry to allow for analysis post inspection. The system architecture uses Robot Operating System 2 (ROS 2) for publish/subscribe integration, NVIDIA Isaac Sim and Unity for simulation and visualization, and algorithms such as NVBlox to fuse data into unified 3D overlays. This robot-agnostic approach reduces operator burden by enabling autonomy across heterogeneous platforms and lets each robot be used where it is strongest. Having autonomous functions means operators don’t have to fully control multiple different components. The ease of use could allow for more widespread adoption of advanced robotics at waste management sites that see continued use. By coordinating simpler, purpose-built mechanisms, the approach lowers design and manufacturing complexity, reduces capital risk in contaminated settings, and improves controllability for complex inspection and manipulation tasks. We present the architecture, early results, and lessons learned from building and deploying this coordinated multi-robot system, with the goal of accelerating safe, cost-effective adoption of advanced robotics at waste-management sites.

42 - ENGINEERING↗

Proposed Risk-Based Approach for Nitrosamine Chemicals of Potential Concern

This report documents the re-evaluation of Hanford Tank Farm (HTF) occupational exposure limits (OEL) for five N-nitrosamines identified as Chemicals of Potential Concern (COPC), and two other N-nitrosamines being considered as COPCs. N-nitrosamines are genotoxic, and exposure has been historically regulated based on cancer as the endpoint of concern. Currently, HTF OELs are based on German Maximum Arbeitsplatz Konzentration values that are no longer used. The National Institute of Occupational Safety and Health (NIOSH) recently released new policy applying a risk-based approach to develop OELs for occupational carcinogens and plans to release guidance on specific chemicals in the future. Consistent with this new NIOSH policy, Pacific Northwest National Laboratory proposes a risk-based approach to establish risk-specific doses for occupational exposures to N-nitrosamine COPCs. This approach establishes a range of N-nitrosamine inhalation exposures associated with risk levels that can be used as a tool for protecting HTF workers. Updated guidance from NIOSH or other authoritative bodies on N-nitrosamine OELs should trigger a re-evaluation of this proposed approach.

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTAN↗

Direct Feed Low Activity Waste Integrated Permitting - 16642

An overall Hanford permitting strategy for the U. S. Department of Energy (DOE) Office of River Protection (ORP) is being developed to support the Direct Feed Low- Activity Waste (DFLAW) Program. The strategy identifies new permits and modifications of existing permits, as well as major regulatory approvals to support the startup and operation of nuclear systems necessary to feed low activity tank waste, pretreat the waste, operate the Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) facility to treat tank waste, and dispose of waste streams. Types of permits include hazardous waste, toxic air, and radiological air licenses. Four different Contractors manage operations at Tank Farms, WTP, Utilities/Infrastructure, and Waste Disposal. Due to this complexity and the number of interfaces required, the need to have a strategic overview of all permits was evident. Approximately 25 permits and 4 major regulatory approvals are identified to implement DFLAW. The strategy will help guide integrated planning, scheduling and sequencing of permits and regulatory approvals to support DOE ORP's overall schedule for construction, commissioning and operation of DFLAW. Development of the strategy included extensive collaboration and coordination of an Integrated Permitting Team with staff and management representation from DOE, CH2M Hill Plateau Remediation Contractor (CHPRC), Washington River Protection Solutions LLC (WRPS), and Bechtel National Inc. (BNI). Information sessions and briefings have been conducted with the Washington State Department of Ecology (Ecology) and Washington State Department of Health (DOH) in the development of this overall strategy. Additionally, interface meetings are held with Ecology and DOH on specific projects early in the design phase to validate the permitting approach, identify key issues and information, and discuss requirements and assumptions. (authors)

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DECONTAMINATION FACTORS AND FILTRATION FLUX IMPACT TO ARP AT REDUCED MST CONCENTRATION

Tank Farm and Closure Engineering is evaluating changes to the Actinide Removal Process facility operations to decrease the MST concentration from 0.4 g/L to 0.2 g/L and the contact time from 12 hours to between 6 and 8 hours. For this evaluation, SRNL reviewed previous datasets investigating the performance of MST at 0.2 g/L in salt solutions ranging from 4.5 to 7.5 M in sodium concentration. In general, reducing the MST concentration from 0.4 to 0.2 g/L and increasing the ionic strength from 4.5 to 7.5 M in sodium concentration will decrease the measured decontamination factors for plutonium, neptunium, uranium and strontium. The decontamination factors as well as single standard deviation values for each sorbate are reported. These values are applicable within the sorbate and sodium concentrations used in the experimental measurements. Decreasing the MST concentration in the ARP from 0.4 g/L to 0.2 g/L will produce an increase in the filter flux, and could lead to longer operating times between filter cleaning. The increase in flux is a function of a number of operating parameters, and is difficult to quantify. However, it is estimated that the reduction in MST could result in a reduction of filtration time of up to 20%.

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Development of a Conditioned System-Level Groundwater Model to Evaluate Long-Term Groundwater Impacts within a Performance Assessment - 20115

A preliminary performance assessment (PA) of single-shell tank Waste Management Area (WMA) A-AX located at the U.S. Department of Energy (DOE)'s Hanford Site in southeastern Washington is being conducted to satisfy the requirements of DOE Order 435.1 [1] as it relates to closure of the single-shell radioactive waste tanks in the WMA A-AX tank farms. A PA assesses the fate, transport, and impacts of radionuclides within a low-level radioactive waste disposal facility in its assumed closure configuration and the subsequent potential doses to humans over a 1,000-year compliance period and a 10,000-year performance evaluation period. The WMA A-AX preliminary PA evaluation is structured around the complementary use of process-level and system-level models to calculate the facility performance against established DOE Order 435.1 [1] performance objectives. Process-level models are those that represent a detailed phenomenological representation of processes of concern in the PA. Process models typically only represent one or a few of the components of the PA, such as groundwater flow and transport, and must be integrated with other modeling elements to perform PA calculations. System-level models are those that are abstracted from the process models, retaining the essential features of the process model, while allowing integration of all aspects of the PA in a single modeling framework. System-level models are often characterized by coarser numerical discretization, lower dimensionality, or other similar simplifications compared to the process-level model. Traditionally, a three-dimensional (3-D) process-level model is utilized primarily to evaluate the long-term impact on groundwater and the potential doses to individuals who consume contaminated groundwater. System-level models are also utilized to evaluate the groundwater pathway in PAs. These models typically have reduced dimensionality (1-D) and are conditioned utilizing flow fields (Darcy fluxes) and moisture content distributions that are abstracted from the process level models. The abstraction approach assures that the flow field in both models is consistent for a specific set of input parameters for flow, differing only in the discretization and dimensionality of the two models. The preliminary WMA A-AX PA incorporates a detailed representation of the geological system and hydraulic properties within the 3-D model STOMP{sup C} numerical code so that the effects of relevant features and processes on water flow and radionuclide transport in the subsurface can be evaluated. The complementary system-level model is developed utilizing the GoldSim{sup C} code to implement a simplified, 1-D equivalent model to represent the groundwater pathway. Contaminant transport through the vadose zone and unconfined aquifer for Tc-99 and I-129 were evaluated in each of the models. Adjustments to the saturated portion of the GoldSim{sup C} 1-D model were required to mimic the dispersion effect captured with the 3-D STOMP{sup C} model. Once this conditioning was conducted, highly similar results for the transport of Tc-99 and I-129 were achieved at the point of calculation, located 100 m downgradient from the WMA A-AX fenceline. These radionuclides represent elements that are regarded as primary dose drivers in the PA groundwater pathway analysis. The high degree of conformance between the two models suggests that the use of the equivalent 1-D system model is suitable for evaluating the full suite of radionuclides that will be released from the tank sources within WMA A-AX over the 1,000-year compliance period and over the 10,000-year evaluation period. (authors)

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Real-time Erosion-Corrosion Detection in Waste Transfer Pipelines using Guided Wave Ultrasonic Sensors - 18368

A Fitness-for-Service (FFS) program for the Waste Transfer System has been implemented by the United States Department of Energy Hanford Site Tank Farm to examine structural parameters of the waste transfer systems in order to develop erosion/corrosion rates for relevant system components. The FFS information is acquired from opportunistic evaluations of pipelines that have been removed from service. The objective is to deliver more realistic estimates to the remaining useful life of the components and incorporate those estimates into future design/testing plans across the DOE complex. To aid to this objective, previous efforts at Hanford included the installation of sensors on some of the POR 104 components, to provide real time pipe wall thickness measurements. Due to certain limitations, alternative approaches for remote permanently mounted pipe wall ultrasonic thickness measurement systems have been investigated by FIU. Present research work is a supportive effort by FIU-ARC for DOE and WRPS, which investigates the option for remote-permanently mount guided wave ultrasonic transducer (UT) systems for HLW pipe wall thickness measurements. Specific applications include straight sections, elbows and other fittings used in jumper pits, evaporators, and valve boxes. The proposed method will provide information that will assist engineers with understanding the failure potential of HLW transfer components due to corrosion and erosion. This information can assist in determining if and when lines need to be removed, saving time and resources on the unneeded excavation of transfer lines. This information will also assist engineers with designing new transfer systems by establishing more detailed/accurate guidelines governing the life expectancy of the transfer system and its components. In the previous work, FIU has investigated the use of various ultrasonic systems that are either commercially available or used previously at Hanford and selected the most promising systems for further evaluation. The down-selected system is the guided wave UT sensor system from Permasense which is a UK based manufacturer. It is an integrated wireless sensor network system which used a patented technology for the acoustic wave propagation and has proven applications in the oil and gas industries. Scope of the present research includes the initial verification and validation of the Permasense Guided Wave sensor system as a potential erosion/corrosion detection system for carbon steel pipelines under static conditions. In future, the real-time erosion/corrosion detection will be investigated by measuring the thinning of the pipe sections by circulating simulants and continuous monitoring. This is achieved by passing abrasive and caustic solutions through an in-house designed pipe loop system. Results obtained provide realistic wear rates on 2 inch and 3 inch carbon steel pipes with straight sections and elbows using the Permasense UT sensor system. Thus, the present research delivers solutions for sensor evaluations, conducts bench scale testing followed by data acquisition and analysis for corrosion and erosion assessment. (authors)

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