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DOE OSTI2024

Design and Materials of Reference Electrodes for Radioactive Waste Tank Service – A Literature Review

The Hanford site stores approximately 55 million gallons of radioactive and chemically hazardous wastes from the production of weapons materials. The wastes are stored in 177 underground, carbon steel storage tanks, 149 of these are single shell tanks (SSTs) and 28 of these are double shell tanks (DSTs). The DSTs provide critical retrieval and interim storage before the waste is vitrified in the Waste Treatment and Isolation Plant (WTP). The DSTs have been in service for 38 to 56 years and current plans indicate that WTP operations will be completed in 2075. Thus, the tanks will need to remain in service far beyond the initial 40-year life expectancy. For life extension of the tanks, effective corrosion control practices must remain in force. This effort includes direct measurements of the extent of corrosion (e.g., ultrasonic measurements and corrosion coupons) and electrochemical processes (e.g., linear polarization measurements).

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DOE OSTI2025

Processes in Salt Repositories for Radioactive Waste Disposal

This document summarizes the key processes (thermal, hydrological, mechanical, and chemical; THMC) impacting the features of a deep geological repository for radioactive waste in salt. Some processes are natural and on-going whether the repository is there or not, and other processes are driven by the perturbation associated with the repository. The features considered here include both engineered and natural components of the repository system. The engineered barrier system (EBS) in a salt repository is quite different from those implemented for a repository in clay or crystalline rocks, because it is comprised mostly of granular salt and salt-compatible cements, rather than bentonite. When compared to other rocks (i.e., silicates), salt has unique properties that make it an excellent potential host rock. Openings and fractures in salt creep closed readily. Salt has high thermal conductivity, which can reduce peak temperatures. Additionally, far away from the excavations the porosity of salt is unconnected, which leads to essentially zero advective or diffusive transport. The small amount of hypersaline brine occurring in salt minimizes microbial activity, reduces colloid-assisted transport, and eliminates in-package criticality (i.e., chloride is a neutron poison). At the end of the report, we present a brief outline for a potential salt repository, including considerations avoided in previous repository disposal concepts. We propose considering higher-temperature processes in future disposal concepts, rather than trying to minimize the thermal perturbation of the repository. Since hot salt is drier, a dry repository would limit corrosion, gas generation, and solute transport. Openings and fractures creep shut faster in hot salt. Therefore, higher temperatures could be seen as beneficial, rather than something to minimize, through increased spacing between waste packages (increasing repository costs).

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DOE OSTI2024

Cliff Retreat Rates Associated with a Low-Level Radioactive Waste Disposal Facility in Los Alamos, New Mexico, USA

We present an analysis and interpretation of potential cliff stability at a low-level waste disposal facility at Los Alamos National Laboratory, New Mexico, using cliff morphologic and fracture characteristics coupled with carbon-14 surface exposure dating. Our study is important as it directly bears on the licensing criteria for low-level radioactive waste sites. We find that future characteristic cliff failures will likely not breach disposal pits and shafts over the 1000-year minimum regulatory period. Further, we find, using a multivariate regression model, that slope angle and cliff face aspect are sub-equal in importance to predict regions of high risk of failure when combined with surface exposure ages and assuming that old exposure ages are most indicative of stability (instability) and therefore can aid decision making in final design implementation.

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DOE OSTI2013

FABRICATION AND DEPLOYMENT OF THE 9979 TYPE AF RADIOACTIVE WASTE PACKAGING FOR THE DEPARTMENT OF ENERGY

This paper summarizes the development, testing, and certification of the 9979 Type A Fissile Packaging that replaces the UN1A2 Specification Shipping Package eliminated from Department of Transportation (DOT) 49 CFR 173. The DOT Specification Package was used for many decades by the U.S. nuclear industry as a fissile waste container until its removal as an authorized container by DOT. This paper will discuss stream lining procurement of high volume radioactive material packaging manufacturing, such as the 9979, to minimize packaging production costs without sacrificing Quality Assurance. The authorized content envelope (combustible and non-combustible) as well as planned content envelope expansion will be discussed.

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DOE OSTI2013

TRANSIENT HEAT TRANSFER ANALYSIS FOR SRS RADIOACTIVE TANK OPERATION

The primary objective of the present work is to perform a heat balance study for type-I waste tank to assess the impact of using submersible mixer pumps during waste removal. The temperature results calculated by the model will be used to evaluate the temperatures of the slurry waste under various tank operating conditions. A parametric approach was taken to develop a transient model for the heat balance study for type-I waste tanks such as Tank 11, during waste removal by SMP. The tank domain used in the present model consists of two SMP's for sludge mixing, one STP for the waste removal, cooling coil system with 36 coils, and purge gas system. The sludge waste contained in Tank 11 also has a decay heat load of about 43 W/m{sup 3} mainly due to the emission of radioactive gamma rays. All governing equations were established by an overall energy balance for the tank domain, and they were numerically solved. A transient heat balance model used single waste temperature model, which represents one temperature for the entire waste liquid domain contained in the tank at each transient time.

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DOE OSTI2013

Collaboration, Automation, and Information Management at Hanford High Level Radioactive Waste (HLW) Tank Farms

Washington River Protection Solutions (WRPS), operator of High Level Radioactive Waste (HLW) Tank Farms at the Hanford Site, is taking an over 20-year leap in technology, replacing systems that were monitored with clipboards and obsolete computer systems, as well as solving major operations and maintenance hurdles in the area of process automation and information management. While WRPS is fully compliant with procedures and regulations, the current systems are not integrated and do not share data efficiently, hampering how information is obtained and managed.

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DOE OSTI2013

ADMINISTRATIVE AND ENGINEERING CONTROLS FOR THE OPERATION OF VENTILATION SYSTEMS FOR UNDERGROUND RADIOACTIVE WASTE STORAGE TANKS

Liquid radioactive wastes from the Savannah River Site are stored in large underground carbon steel tanks. The majority of the waste is confined in double shell tanks, which have a primary shell, where the waste is stored, and a secondary shell, which creates an annular region between the two shells, that provides secondary containment and leak detection capabilities should leakage from the primary shell occur. Each of the DST is equipped with a purge ventilation system for the interior of the primary shell and annulus ventilation system for the secondary containment. Administrative flammability controls require continuous ventilation to remove hydrogen gas and other vapors from the waste tanks while preventing the release of radionuclides to the atmosphere. Should a leak from the primary to the annulus occur, the annulus ventilation would also serve this purpose. The functionality of the annulus ventilation is necessary to preserve the structural integrity of the primary shell and the secondary. An administrative corrosion control program is in place to ensure integrity of the tank. Given the critical functions of the purge and annulus ventilation systems, engineering controls are also necessary to ensure that the systems remain robust. The system consists of components that are constructed of metal (e.g., steel, stainless steel, aluminum, copper, etc.) and/or polymeric (polypropylene, polyethylene, silicone, polyurethane, etc.) materials. The performance of these materials in anticipated service environments (e.g., normal waste storage, waste removal, etc.) was evaluated. The most aggressive vapor space environment occurs during chemical cleaning of the residual heels by utilizing oxalic acid. The presence of NO{sub x} and mercury in the vapors generated from the process could potentially accelerate the degradation of aluminum, carbon steel, and copper. Once identified, the most susceptible materials were either replaced and/or plans for discontinuing operations are executed.

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DOE OSTI2013

Operating Experience and Lessons Learned in the Use of Soft-Sided Packaging for Transportation and Disposal of Low Activity Radioactive Waste

This paper describes the operating experience and lessons learned at U.S. Department of Energy (DOE) sites as a result of an evaluation of potential trailer contamination and soft-sided packaging integrity issues related to the disposal of low-level and mixed low-level (LLW/MLLW) radioactive waste shipments. Nearly 4.3 million cubic meters of LLW/MLLW will have been generated and disposed of during fiscal year (FY) 2010 to FY 2015—either at commercial disposal sites or disposal sites owned by DOE. The LLW/MLLW is packaged in several different types of regulatory compliant packaging and transported via highway or rail to disposal sites safely and efficiently in accordance with federal, state, and local regulations and DOE orders. In 1999, DOE supported the development of LLW containers that are more volumetrically efficient, more cost effective, and easier to use as compared to metal or wooden containers that existed at that time. The DOE Idaho National Engineering and Environmental Laboratory (INEEL), working in conjunction with the plastic industry, tested several types of soft-sided waste packaging systems that meet U.S. Department of Transportation requirements for transport of low specific activity and surface contaminated objects. Since then, soft-sided packaging of various capacities have been used successfully by the decontamination and decommissioning (D&D) projects to package, transport, and dispose D&D wastes throughout the DOE complex. The joint team of experts assembled by the Energy Facility Contractors Group from DOE waste generating sites, DOE and commercial waste disposal facilities, and soft-sided packaging suppliers conducted the review of soft-sided packaging operations and transportation of these packages to the disposal sites. As a result of this evaluation, the team developed several recommendations and best practices to prevent or minimize the recurrences of equipment contamination issues and proper use of soft-sided packaging for transport and disposal of waste.

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DOE OSTI2015

Mixed-layered bismuth--oxygen--iodine materials for capture and waste disposal of radioactive iodine

Materials and methods of synthesizing mixed-layered bismuth oxy-iodine materials, which can be synthesized in the presence of aqueous radioactive iodine species found in caustic solutions (e.g. NaOH or KOH). This technology provides a one-step process for both iodine sequestration and storage from nuclear fuel cycles. It results in materials that will be durable for repository conditions much like those found in Waste Isolation Pilot Plant (WIPP) and estimated for Yucca Mountain (YMP). By controlled reactant concentrations, optimized compositions of these mixed-layered bismuth oxy-iodine inorganic materials are produced that have both a high iodine weight percentage and a low solubility in groundwater environments.

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DOE OSTI2015

Special Analysis for the Disposal of the West Valley Demonstration Project Extraction Cell 2 Low Density Waste Stream at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

This special analysis (SA) evaluates whether the West Valley Demonstration Project (WVDP) Extraction Cell 2 Low Density waste stream is suitable for disposal by shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) on the Nevada National Security Site (NNSS). The WVDP Low Density waste stream consists of debris contaminated during the decontamination and decommissioning (D&D) of Extraction Cell 2 at the WVDP (WVDP 2015). The WVDP Low Density waste stream required an SA because the radium-226 (226Ra) activity concentration exceeds the NNSS Waste Acceptance Criteria (WAC) Action Level (U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office [NNSA/NFO] 2013). The effect of adding the WVDP Low Density waste stream inventory to the inventory of waste disposed through the end of FY 2014 was evaluated with the A5 RWMS v 4.119 PA model. The results indicate that all performance objectives can be met with disposal of the WVDP Low Density in a SLB trench. Addition of the WVDP Low Density inventory slightly increases the 222Rn flux density, but the maximum mean and 95th percentile flux density remain less than the performance objective throughout the compliance period. The WVDP Low Density waste stream had no significant effect on the maximum mean and 95th percentile for all other PA results. The WVDP Low Density waste stream, therefore, is suitable for disposal by SLB at the Area 5 RWMS.

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DOE OSTI2015

Special Analysis for the Disposal of the Lawrence Livermore National Laboratory EnergyX Macroencapsulated Waste Stream at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

This special analysis (SA) evaluates whether the Lawrence Livermore National Laboratory (LLNL) EnergyX Macroencapsulated waste stream (B LAMACRONCAP, Revision 1) is suitable for disposal by shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site (NNSS). The LLNL EnergyX Macroencapsulated waste stream is macroencapsulated mixed waste generated during research laboratory operations and maintenance (LLNL 2015). The LLNL EnergyX Macroencapsulated waste stream required a special analysis due to tritium (3H), cobalt-60 (60Co), cesium-137 (137Cs), and radium-226 (226Ra) exceeding the NNSS Waste Acceptance Criteria (WAC) Action Levels (U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office [NNSA/NFO] 2015).The results indicate that all performance objectives can be met with disposal of the waste stream in a SLB trench. Addition of the LLNL EnergyX Macroencapsulated inventory slightly increases multiple performance assessment results, with the largest relative increase occurring for the all-pathways annual total effective dose (TED). The maximum mean and 95th percentile 222Rn flux density remain less than the performance objective throughout the compliance period. The LLNL EnergyX Macroencapsulated waste stream is suitable for disposal by SLB at the Area 5 RWMS. The waste stream is recommended for approval without conditions.

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DOE OSTI2015

Special Analysis for the Disposal of the Lawrence Livermore National Laboratory Low Activity Beta/Gamma Sources Waste Stream at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

This special analysis (SA) evaluates whether the Lawrence Livermore National Laboratory (LLNL) Low Activity Beta/Gamma Sources waste stream (BCLALADOEOSRP, Revision 0) is suitable for disposal by shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site (NNSS). The LLNL Low Activity Beta/Gamma Sources waste stream consists of sealed sources that are no longer needed. The LLNL Low Activity Beta/Gamma Sources waste stream required a special analysis because cobalt-60 (60Co), strontium-90 (90Sr), cesium-137 (137Cs), and radium-226 (226Ra) exceeded the NNSS Waste Acceptance Criteria (WAC) Action Levels (U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office [NNSA/NFO] 2015). The results indicate that all performance objectives can be met with disposal of the LLNL Low Activity Beta/Gamma Sources in a SLB trench. The LLNL Low Activity Beta/Gamma Sources waste stream is suitable for disposal by SLB at the Area 5 RWMS. However, the activity concentration of 226Ra listed on the waste profile sheet significantly exceeds the action level. Approval of the waste profile sheet could potentially allow the disposal of high activity 226Ra sources. To ensure that the generator does not include large 226Ra sources in this waste stream without additional evaluation, a control is need on the maximum 226Ra inventory. A limit based on the generator’s estimate of the total 226Ra inventory is recommended. The waste stream is recommended for approval with the control that the total 226Ra inventory disposed shall not exceed 5.5E10 Bq (1.5 Ci).

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DOE OSTI2019

FX2 Fogging Fixative Deployment for Radioactive Contamination Control

Idaho National Laboratory’s FX2 fixative solution was deployed as part of the decontamination and decommissioning (D&D) of an alpha-contaminated glovebox. The fixative was dispensed via fogging. The goal of the deployment was to reduce friable alpha radioactive contamination prior to removal of the glovebox. Information about the deployment and the efficacy of the treatment is presented.

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DOE OSTI2021

NEVADA NATIONAL SECURITY SITE 2020 DATA REPORT- GROUNDWATER MONITORING PROGRAM AREA 5 RADIOACTIVE WASTE MANAGEMENT SITE

This report presents groundwater and leachate sample results from the Area 5 Radioactive Waste Management Site (RWMS) at the Nevada National Security Site in Nye County, Nevada. Since 1993, groundwater samples have been collected and static groundwater depths have been measured from the aquifer immediately below the Area 5 RWMS. The data are evaluated for evidence of effects on the aquifer related to the Area 5 RWMS. Leachate from the Cell 18 lined mixed waste cell has been sampled since 2011, and leachate from the Cell 25 lined mixed waste cell was first sampled in 2019 after it began receiving waste in August 2018. Leachate data are analyzed for hazardous contaminants to determine appropriate leachate handling and disposal. This report includes five years of data from 2016 through 2020.

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DOE OSTI2022

NEVADA NATIONAL SECURITY SITE 2021 WASTE MANAGEMENT MONITORING REPORT AREA 3 AND AREA 5 RADIOACTIVE WASTE MANAGEMENT SITES

Environmental monitoring data are collected at and around the Area 3 and Area 5 Radioactive Waste Management Sites (RWMSs) within the Nevada National Security Site (NNSS). This report summarizes the 2021 environmental data to provide an overall evaluation of RWMS performance and to support environmental compliance and performance assessment (PA) activities.

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DOE OSTI2013

Development and Testing of Techniques for In-Ground Stabilization, Size Reduction and Safe Removal of Radioactive Wastes Stored in Large Containments in Burial Grounds - 13591

Radioactive waste materials, including Transuranic (TRU) wastes from laboratories have been stored below ground in large containments at a number of sites in the US DOE Complex, and at nuclear sites in Europe. These containments are generally referred to as caissons or shafts. The containments are in a range of sizes and depths below grade. The caissons at the DOE's Hanford site are cylindrical, of the order of 2,500 mm in diameter, 3,050 mm in height and are buried about 6,000 mm below grade. One type of caisson is made out of corrugated pipe, whereas others are made of concrete with standard re-bar. However, the larger shafts in the UK are of the order of 4,600 mm in diameter, 53,500 mm deep, and 12,000 below grade. This paper describes the R and D work and testing activities performed to date to evaluate the concept of in-ground size reduction and stabilization of the contents of large containments similar to those at Hanford. In practice, the height of the Test Facility provided for a test cell that was approximately 22' deep. That prevented a 'full scale mockup' test in the sense that the Hanford Caisson configuration would be an identical replication. Therefore, the project was conducted in two phases. The first phase tested a simulated Caisson with surrogate contents, and part of a Chute section, and the second phase tested a full chute section. These tests were performed at VJ Technologies Test Facility located in East Haven, CT, as part of the Proof of Design Concept program for studying the feasibility of an in-situ grout/grind/mix/stabilize technology for the remediation of four caissons at the 618-11 Burial Ground at US Department of Energy Hanford Site. The test site was constructed such that multiple testing areas were provided for the evaluation of various tools, equipment and procedures under conditions that simulated the Hanford site, with representative soils and layout dimensions. (authors)

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