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DOE OSTI2019

Development of Processing Technology for Radioactively Contaminated Water at Chernobyl Nuclear Power Plant - 19656

During the operation of the Chernobyl Nuclear Power Plant, distillation by evaporation was the main method for processing radioactively contaminated water. When the plant was decommissioned, the evaporation facility was mothballed and floor drain treatment was suspended in 2016. At present, the existing tanks with the capacity of 26,000 m{sup 3} are more than 60% full with radioactively contaminated floor drains, which requires alternative processing methods. The current process flow for radioactive waste management at State Specialized Enterprise 'Chernobyl NPP' includes processing of accumulated liquid radioactive wastes at a liquid radioactive wastes processing plant. Under the processing technology, liquid radioactive waste is immobilized at the plant by cementation and the resulting solid radioactive waste is then buried in a near-surface storage. Key factors for the selection of alternative radioactively contaminated water processing methods are the possibility to clear the processed water (no control monitoring), which requires the same degree of processing as for drinking water, and minimization of radioactive waste generation due to the lack of free space for solid waste disposal in the near-surface storage. Floor drains that require processing contain radionuclides such as {sup 137}Cs, {sup 90}Sr, {sup 60}Co and {sup 40}K. The current level of the total beta and gamma activity is about 4*105 Bq/kg. The following criteria are set for the Chernobyl NPP site for water to be disposed to the sewerage system: - Max. 37 Bq/kg for the total beta and gamma containing radionuclide activity; - Max. 0.7 Bq/kg for the total alpha containing radionuclide activity. METOIL produces inorganic sorbents for removing radionuclides from liquids and develops sorbent-based technology for a variety of applications related to liquid radioactive waste processing. In 2017-2018, experts from the Chernobyl NPP and METOIL ran several joint laboratory tests to evaluate the efficiency of inorganic sorbents made by METOIL for processing floor drains at the Chernobyl NPP. The test procedure included treatment of radioactively contaminated water in a two-stage sorption process: static sorption (sorbents are mixed in a liquid) and dynamic sorption (the liquid is filtered through a sorbent column). NIKET and MODIKS sorbents were provided for the tests. The results of the test measurements showed that the total alpha containing radionuclide activity is less than 0.026 Bq/kg and the total beta and gamma containing radionuclide activity is 9.2 Bq/kg. The physical and chemical parameters after processing also met the water disposal criteria. High sorption capacity of the sorbents used for the tests allows processing hundreds of water volumes with just one sorbent volume. At present, preparations are underway for full-scale tests at a pilot plant with a capacity of minimum 10 m{sup 3}/day. At a later stage, spent sorbents may be immobilized by inclusion into the cement matrix, which will substantially reduce the amount of radioactive waste to be buried. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2021

A novel defoamer for processing nuclear waste: Testing and performance

Abstract Legacy radioactive waste from nuclear weapons material processing is the biggest environmental challenge in the state of South Carolina, and one of the biggest in the United States. Although substantial progress has been made in processing and vitrifying high‐level radioactive waste at the Savannah River site, approximately 35 million gallons remains to be treated and dispositioned. In this article, we show the development of a new defoamer for use in the processing of high‐level radioactive waste. The application of the new defoamer is not only more effective at controlling foam but will shorten the batch processing time leading to safer and more efficient processing. This has the potential to help shorten the overall site mission lifetime, saving the federal government hundreds of millions of dollars. The novel aspect of the new defoamer is its effectiveness and stability in the harsh conditions needed for processing high‐level radioactive waste: high temperatures, pH 4–13, strong oxidizing and reducing agents, and numerous metal catalysts. The defoamer will replace an existing antifoam agent that decomposes to form multiple flammable gases. Because the existing antifoam agent decomposes quickly, processing changes increased processing time. Statement of novelty We demonstrate that a new defoamer has been developed for use in processing high‐level radioactive waste. This novel defoamer is effective and stable in the harsh processing conditions with no detectable flammable by‐products. Because the existing antifoam agent decomposes quickly, processing changes, including lowering acid addition rates and evaporation rates, increased processing time. The new defoamer is not only more effective at controlling foam but will shorten the batch processing time and lead to safer and more efficient processing by eliminating the production of flammable gases. Statement of industrial relevance Foaming is of great concern in many industrial processes involving three‐phase gas/liquid/fine‐solids systems, like in water evaporation, mineral floatation, air sparging in situ remediation techniques, and in those found in the paper industry.

Lambert, Dan P.↗
NASA NTRS1973

Feasibility of Space Disposal of Radioactive Nuclear Waste. 1: Executive Summary

This NASA study, performed at the request of the AEC, concludes that transporting radioactive waste (primarily long-lived isotopes) into space is feasible. Tentative solutions are presented for technical problems involving safe packaging. Launch systems (existing and planned), trajectories, potential hazards, and various destinations were evaluated. Solar system escape is possible and would have the advantage of ultimate removal of the radioactive waste from man's environment. Transportation costs would be low (comparable to less than a 5 percent increase in the cost of electricity) even though more than 100 space shuttle launches per year would be required by the year 2000.

Source record↗
DOE OSTI2019

Effects of bentonite heating on U(VI) adsorption

Engineered barrier systems designed to isolate high-level radioactive waste utilize bentonite, a montmorillonite rich material, to restrict contaminant transport due to its low hydraulic conductivity and high adsorption capacity. High temperatures (100–200 °C) near waste canisters resulting from radioactive decay may alter the clay's ability to adsorb contaminants. In this study, we examine U(VI) adsorption onto two different bentonite samples subjected to (1) 18 years of in situ heating during an underground experiment and (2) short-term (7-week), high temperature (300 °C) heating in the laboratory. Results show that U(VI) adsorption was lower for field-heated bentonite located closest to the heater, which experienced temperatures of approximately 95 °C, compared to a control sample, which experienced temperatures of approximately 20 °C, over a range of aqueous chemical conditions. On average, K d values for U(VI) adsorption were 31% lower for 95 °C heated samples. By contrast, U(VI) adsorption onto intermediate-heated bentonite (50 °C) was indistinguishable from the adsorption onto the cold-zone (20 °C) sample. U(VI) adsorption onto lab-heated bentonite was also lower than onto control bentonite over the pH range 4.5–8.0, with an average decrease in K d values of 50% after heating. Lower U(VI) adsorption to field-heated bentonite persisted after bentonite was purified to isolate the clay fraction. This allows us to rule out changes in pore-water chemistry or accessory mineral composition as causes of the lower adsorption. No evidence of montmorillonite illitization was observed in the heated samples. While some of the lower U(VI) adsorption in the lab-heated bentonite can be explained by changes in aqueous U(VI) speciation, we propose that lower U(VI) adsorption to field-heated bentonite may be primarily due to changes in the montmorillonite edge structure. The observed changes in U(VI) adsorption to bentonite after heating have implications for U(VI) diffusive transport through engineered barriers and must be considered when designing radioactive waste disposal repositories.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2021

System Model Calculations for the Active Trenches of the Low-Level Burial Grounds, Hanford Site, Washington

Two lined trenches (Trench 31 and 34) located within the 200 West Low-Level Burial Ground (LLBG) area of the U.S. Department of Energy’s (DOE) Hanford Site are designated for permanent disposal of low-level radioactive waste (LLW) and mixed low-level radioactive waste (MLLW). In accordance with DOE O 435.1, Radioactive Waste Management, radioactive waste shall be managed and disposed in a manner that is protective of worker, public health and safety, and the environment. DOE O 435.1 requires a site-specific radiological performance assessment (PA) that includes calculations of potential releases and subsequent doses to members of the public for a period of 1,000 years after closure of a low-level waste (LLW) disposal facility. The purpose of this environmental calculation file (ECF) is to document the various dose calculations performed to support DOE’s LLBG PA. The dose assessments are performed to evaluate the potential exposure of an all-pathway representative person to radionuclide contaminants of potential concern (COPCs) that may be released from the LLBG Trenches 31 and 34 to the point of calculation (POC) located at the outer edge of a 100 m buffer zone surrounding the trench boundary. This ECF uses inputs from other ECFs and their associated model package reports (MPRs) supporting the LLBG PA. The five major objectives of this ECF are to present the results of the following: (1) Deterministic dose assessments for both groundwater and atmospheric exposure scenarios; (2) Radon-222 (Rn-222) flux emanating at the surface from the disposed wastes; (3) Uncertainty analyses of the groundwater pathway annual dose due to uncertainty in input parameters; (4) Sensitivity analyses of the input parameters that could potentially impact the fate and transport of the contaminants and doses; (5) Doses arising from inadvertent intruder exposure scenarios.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Panel Session 105: US DOE LLW On-Site Disposal: LLW Disposal Facility Federal Review Group Review Process

This panel focuses on risk-informed provision for waste management of US DOE radioactive wastes. Detailed information on the high-level radioactive waste interpretation Federal Register Notice will be discussed to better educate the audience in understanding that interpretation. The Co-Chairs and panelists each introduced themselves. Presentations proposed include: 1 - Overview of Public Comments on the Proposed High-Level Radioactive Waste Interpretation (Theresa Kliczewski, US DOE EM (USA)); 2 - ECA Presentation on Implementation Approaches and Expectations for Radwaste Management; DOE Order 435.1 (Kara Colton, Energy Communities Alliance (USA)); 3 - 2019 Grassroots Efforts to Clarify HLW Definition (Rick McLeod, Savannah River Site Community Reuse Organization - SRSCRO (USA))

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

Low Level Radon Concentration and Radon Daughter Dose Monitoring in an Arid-zone Waste Store - 20081

Radioactive waste containing predominantly soil and rubble from the clean-up of a former uranium and thorium minerals processing research facility is currently stored at the Woomera Test Range in South Australia awaiting final disposal. Prior to commencing any manipulation of the nearly 10,000 waste drums (205 L or 55 gallon each), radon concentration monitoring and radon daughter dosimetry has been undertaken to (i) gain understanding of the temporal and spatial variation of radon and its daughters within the storage facility, which could provide insights into the radiological source term and (ii) confirm that radiological risks to workers are below the guideline values. A time series of nearly 12 months of detailed observations shows low level radon concentrations with annual average values that are slightly above the average radon concentrations in Australian homes. Peak values in summer are about three times higher than the annual average based on the CRM measurements. Both radon concentrations and annual effective dose are well below the regulatory limits. (authors)

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

Disposition Options for Sodium Cooled Fast Reactor (A White Paper)

The sodium-cooled fast reactor (SFR) design concept is one of the six classes of nuclear reactors in the GenIV initiative. SFRs are uranium or plutonium-fueled reactors operating in the fast neutron spectrum using liquid sodium as the coolant. SFRs can be designed as a breeder reactor or actinide-burning reactor in addition to operating the thorium fuel cycle. While having different fuel designs, the anticipated waste streams, and the necessary management strategies for spent nuclear fuel (SNF) and radioactive wastes from SFRs are very similar. This includes the SNF, activated sodium coolant, in-core stainless-steel components, piping, resins and filters, solidified liquid waste, contaminated equipment, and other radioactive wastes. Modern SFR designs are based on a long and rich operating history of several liquid-metal-cooled fast reactors with sodium coolant. Several of these reactors have been shut down, the fuel has been placed in safe storage, and they have undergone some degree of decommissioning. As such, there is significant experience in the management of the SNF and radioactive wastes associated with operating these reactors. This white paper will identify the definitions and regulations that apply to the safe and secure management, storage, and disposal of radioactive waste and identify the key radioactive waste streams from SFRs. Idaho National Laboratory has significant experience in the management of the SNF from the SFR predecessors. This experience should form the basis for the management and disposition efforts of the radioactive waste from any new SFR-type small modular reactor or microreactor intended for deployment at the Idaho National Laboratory Site

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2019

Cameco Corporation's Approach to Legacy and Ongoing Waste Management Within the Fuel Services Division - 19124

Since 2011, a Fuel Services Division (FSD) employee has been dedicated to oversee divisional waste management with the goal of accelerating the recycle/disposal of accumulated legacy radioactive wastes stored at its Ontario operations in Blind River and Port Hope. The Blind River Refinery (BRR) and Port Hope Conversion Facility (PHCF) were previously owned by the federal Crown Corporation, Eldorado Nuclear, becoming part of Cameco in 1988 and Cameco Fuel Manufacturing (CFM), previously known as Zircatec Precision Industries, becoming part of Cameco in 2006. Accumulated legacy radioactive waste is stored at each of the facilities. This radioactive waste has accumulated from operations beginning in the 1930's in Port Hope and the 1980's in Blind River. Due to minimal commercially available outlets for the disposal and/or treatment of these wastes, the waste was managed onsite by storage in underutilized space in buildings, trailers and/or in the secured yard. This relatively low-cost practice meant that over decades, the inventory increased at an unsustainable rate until available space became a limiting factor. During this time, the labelling, inventory records, characterization details and other history of many of the waste materials was not maintained adequately. Due to the volume of waste that had accumulated, campaigns to address these deficiencies in information were not considered feasible, sustaining the issue of accumulation of low-level radioactive waste. Since 2011, FSD has completed annual campaigns to address the accumulated legacy waste, which has included processing of material for decontamination to meet the unrestricted release criteria under the Canadian Nuclear Substance and Radiation Devices Regulations (NSRDR), disposal of marginally contaminated wastes (<500 ppm uranium) at a permitted landfill in the United States, processing of contaminated materials to reduce the volume of low-level radioactive waste and disposal at a designated facility in Port Hope. In addition FSD has undertaken significant changes to radioactive waste management practices at each of the facilities. Multiple characterization techniques, including visual observation, review of process and other historical records, laboratory analysis and radiation scanning have been utilized in campaign planning to identify the scope and appropriate waste management technique(s) to reduce the inventory of stored material. This divisional waste management program has resulted in a significant change to how radioactive waste is generated, inventoried, characterized and managed within FSD and has increased the visibility within the leadership team of the opportunities and challenges of waste management, such as alignment with decommissioning planning, project planning and budgeting. The heightened awareness has led to better financial and physical resource planning to execute waste projects with a current projected elimination of the legacy waste within FSD by 2025. (authors)

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

Preliminary Long-term Safety Assessment for the Planned LLW Disposal Facility at Al-Tuwaitha, Iraq - 18142

Before 1991, Iraq had a significant nuclear program which encompassed ten nuclear sites spread out across the country. The largest nuclear site was located at the Al-Tuwaitha site near Baghdad where 18 nuclear facilities were concentrated. During the first Gulf War in 1991, all sites suffered significant damage from bombing and subsequent looting. Currently, the Ministry of Science and Technology is responsible for the ten heavily damaged nuclear sites and for the management of radioactive waste in Iraq in general. The task of decommissioning the damaged nuclear facilities and managing the resulting waste is being supported by the International Atomic Energy Agency (IAEA), the European Commission (EC), and the United States (US). In the framework of its Instrument for Nuclear Safety Cooperation (INSC), the EC has launched a cooperation project to support the planned construction of an engineered repository for short-lived low- and intermediate level waste for the safe disposal of radioactive waste resulting from the decommissioning activities, as well as for waste from the continuing use of radioisotopes in medicine and the oil and gas industry in the country. The main objectives of this project, which was awarded to a Consortium led by NUKEM Technologies Engineering Services GmbH and joined by DBE Technology GmbH of Germany and JAVYS a.s. of Slovakia, are the development of an initial conceptual level basic design and preliminary safety assessment report (PSAR) and the subsequent detailed engineering design and supporting pre-construction safety assessment report (PCSAR). The current paper focuses on the development of the PSAR. Special focus is given to the long-term calculations and difficulties associated with the limited data base in regard to site characterization as well as the expected inventory for the future repository. Because of the ongoing security concerns in Iraq, the Ministry of Science and Technology had already selected the Al-Tuwaitha Site as the best suited location for the planned surface repository at the start of the project. Although some site characterization work had already been carried out prior to the start of the project, certain data for modelling the geology and hydrology of the site are still lacking. Missing data have been compensated by conservative assumptions and the assessment of alternative scenarios. Consequently, for the development of the simplified GoldSim{sup R} computer model used to carry out the long-term calculations supporting the PSAR, existing site information was used and, as appropriate, amended or replaced by conservative assumptions. Due to the nature of the waste, data on the expected inventory are associated with large uncertainties. Although certain estimates related to the future volume of the waste exist, little to no information is available on the expected radionuclide vector and respective activities. Therefore, the long-term calculations were carried out for a generic inventory including a broad range of radionuclides that are to be expected as being important considering the kind of waste to be disposed of in the facility. Based on the results of these calculations, the maximum total capacity of the facility was estimated and converted into activity limits for individual radionuclides that will be integrated into the existing general WAC for the facility. Compliance with these WAC will then guarantee the safety of the repository in regard to potential radionuclide releases via the groundwater pathway. In parallel to the determination of activity limits for the WAC, long-term calculations were carried using different estimates for the expected total activity to determine the general suitability of the proposed technical solution of the repository for receiving the total amount of Iraqi radioactive waste principally acceptable for surface disposal. (authors)

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

Technical Evaluation of the Department of Energy Research and Development Activities in Underground Research Laboratories - 20287

Congress created the U.S. Nuclear Waste Technical Review Board (NWTRB) in the 1987 Nuclear Waste Policy Amendments Act (Public Law 100-203) to evaluate the technical and scientific validity of activities undertaken by the Secretary of Energy to implement the Nuclear Waste Policy Act. Since 2012, DOE has collaborated in research conducted in several underground research laboratories (URLs) located in Europe and Asia. According to DOE, these international collaborations have been beneficial to its spent nuclear fuel (SNF) and high-level waste radioactive (HLW) disposal research program, particularly after the termination of the Yucca Mountain repository program when DOE began generic research on alternative host rocks (crystalline, clay, and salt) and repository environments very different from those at Yucca Mountain. In accordance with its mandate, the NWTRB is reviewing the DOE research and development (R and D) activities related to URLs. The NWTRB's review is documented in a report to Congress and the Secretary of Energy that will be released in January 2020, and this paper summarizes the NWTRB review and findings. The NWTRB held a fact-finding meeting with DOE and subsequently held a workshop on international URL collaborations in April of 2019. Based on the presentations and discussions at the workshop and at the fact-finding meeting, as well as information from reports published by DOE and others, there are four principal findings related to DoE's URL-related R and D activities. First, DOE participation in URL-related international research greatly benefits the U.S. geologic disposal R and D program by furthering its understanding of generic and site-specific disposal issues relevant to alternative repository host rocks and environments. DOE-funded R and D activities also are benefiting the URL-related research of other countries, especially in the area of complex analytical and numerical model/software development. Second, the more developed repository programs in other countries have focused on creating and strengthening their safety cases and making them transparent to the public. Repository programs in other countries use URLs to explain the technical bases underlying their safety cases, periodically reassess knowledge gaps and define new activities to strengthen the technical bases, and demonstrate the technology that will allow implementation of the proposed safety concept. Third, countries with more developed geologic disposal programs have found domestic URLs essential to their repository programs. DOE needs domestic URLs to advance geologic disposal efforts over the next decades and further its ability to train the next generation of scientists, engineers, and skilled technical workers. Fourth, DoE's international URL collaborations have advanced its generic disposal R and D program, including development of modeling capabilities recognized internationally as state-of-the-art, but further work on its coupled thermal-hydrological-mechanical-chemical models and URL- and laboratory-based research can strengthen its program. (authors)

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

3rd Quarter Transportation Report FY2018

This report satisfies the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office (NNSA/NFO) commitment to prepare a quarterly summary report of waste shipments to the Nevada National Security Site (NNSS) Radioactive Waste Management Complex (RWMC) in Area 5. This report summarizes the following types of shipments during the 3rd quarter of fiscal year (FY) 2018: Low-Level Radioactive Waste (LLW), Mixed Low-Level Radioactive Waste (MLLW), Classified Non-Radioactive Waste (CNR,) and Classified Non-Radioactive Hazardous Waste (CNRH).

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

Knowledge Management in Nuclear Liabilities Regulation in the UK - 18155

Within the UK's nuclear safety regulator (Office for Nuclear Regulation; ONR) nuclear liabilities regulation addresses the safe management of radioactive waste, decommissioning and land quality through a facility's lifetime. Higher activity radioactive waste (HAW) could be stored on site for up to 150 years prior to disposal, Magnox decommissioning sites are planned to be in Care and Maintenance for up to 70 years and Sellafield decommissioning is not planned to be complete until after 2100. The long timescales over which decommissioning occurs and radioactive waste is managed is a challenge to maintaining a suitable level of knowledge to effectively and efficiently regulate nuclear liabilities activities. There is a danger that implicit knowledge accumulated over decades could be lost as people retire. Effective knowledge capture and transfer are key elements in maintaining a workforce with the capacity and capability to deliver high levels of nuclear safety, given the demographics of the UK nuclear industry. Maintenance of recorded information over long timescales with changing technologies is necessary to allow safe storage and disposal of waste and intelligent response to incidents. As the safety regulator, ONR's ability to influence improvement in nuclear safety relies on our inspectors having access to high quality knowledge. The ONR Strategy 2016-2020 [1,2] commits to continue to recruit, retain and develop staff so that we have a core workforce with the capacity and capability to deliver high quality, enabling nuclear regulation. Over the next 30 years, the UK plans to develop a geological disposal facility and UK EDF power stations will transition into decommissioning. The ONR Knowledge Management Strategy sets out the activities planned to maintain specialist knowledge to support staff development and build organisational resilience. Guidance on waste management is given in 'The management of higher activity radioactive waste on nuclear licensed sites' (referred to as the Joint Guidance [3]) published by ONR and the UK environmental regulators. It includes our expectations for managing information and records relating to radioactive waste, and introduces the concept of Radioactive Waste Management Cases (RWMCs). Our expectation is that knowledge and records must both be managed and transferred in such a way that future licensees are properly equipped to ensure that waste continues to be managed in a manner that prevents or minimises hazards to human health and the environment. RWMCs are an effective vehicle for demonstrating how the key elements of long-term safety and environmental performance will be delivered over the life cycle of the waste. They give a history of how the waste has been managed, capturing information and change over time. This paper will look at the challenges to managing knowledge in the UK nuclear industry, focusing on the safe management of radioactive waste, decommissioning and land quality. It will look at the problems faced by both licensees and ONR, drawing out common challenges. The paper will outline the approach taken within ONR to capture and communicate waste management and decommissioning knowledge and experience. Finally, it will look at how ONR regulates and influences how knowledge and records are dealt with in the industry to ensure safe nuclear liabilities management in the long term. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2018

Off-Gas Condensate and Cast Stone Analysis Results

A sample of off-gas condensate produced during a demonstration test of the direct-feed low-activity waste (DFLAW) Radioactive Waste Test Platform using waste retrieved from Hanford storage tank AP-105 waste was analyzed for major cations, anions, total cyanide, Resource Conservation and Recovery Act (RCRA) metals, selected radionuclides, and selected organic compounds. The remaining off-gas condensate was concentrated through evaporation and then used to produce Cast Stone waste forms. After the solid waste forms cured for 28 days, U.S. Environmental Protection Agency (EPA) Method 1311 (EPA 1992) Toxicity Characteristic Leach Procedure (TCLP) tests were conducted on two samples. The TCLP leachates were analyzed for RCRA metals, fluoride, and total cyanide. These chemical analyses were conducted to collect data on the waste form performance and to determine if the waste form will meet the disposal requirements of the Waste Control Specialists LLC (WCS) Federal Waste Disposal Facility (FWF) in Texas (WCS 2015) and the Integrated Disposal Facility at Hanford. The radionuclide results in the off-gas condensate were used to estimate concentrations in the Cast Stone waste forms; these estimates were then compared to Class C limits (30 TAC 336.362 Appendix E). With the possible exception of U-232, all measured radionuclides were determined to be below their respective Class C limits. Inductively coupled plasma-mass spectrometry (ICP-MS) was used to measure most of the radionuclides. It is not possible to differentiate the isotope measured at mass 232 between U 232 and Th-232 by mass spectroscopy. Class C limit comparisons were made by assuming two maximum possible scenarios; one in which all the isotope at mass 232 occurred as Th-232, and another assigning the entire mass contribution to U-232. If the isotope at mass 232 is all Th-232 then the waste form is well below its Class C limit; however, if the isotope at mass 232 is all U-232, then the Class C limit would be exceeded by more than a factor of 8. A chemical procedure to separate uranium from thorium followed by reanalysis by ICP-MS would be required to resolve this issue. A similar issue occurs at mass 238, which could be U-238 or Pu-238; however, in this case Pu-238 can be ruled out as a contributor to the isotope measured at mass 238 for the following reasons. Pu-238 has a half-life of 87.7 years and its daughter product (U-234) has a half-life of 2.5 × 105 years and a measured concentration of < 0.002 µg/L. If significant concentrations of Pu-238 were present in this waste, then the amount of measurable U 234 would have increased over the decades of storage in the Hanford tanks. Because this was not observed, it is concluded that the isotope measured at mass 238 is all U-238. A total of 68 organic compounds were targeted for analysis in the off-gas condensate. Of these compounds, only nine were measured above their respective minimum reportable concentration. These compounds were acenaphthene, acetone, n-butyl alcohol, p,p’-DDT, methyl ethyl ketone, nitrobenzene, o nitrophenol, pyridine, and toluene. Of the detectable compounds, only acenaphthene, acetone, o nitrophenol, and pyridine were above wastewater standards (40 CFR 268.48 - Universal Treatment Standards). None of the organic compounds exceeded the non-wastewater standards (40 CFR 268.48 - Universal Treatment Standards). Analysis of the TCLP leachates from the Cast Stone waste forms indicated that none of the analytes exceeded the Universal Treatment Standard and, in general, all were well below the standards.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

An Approach for Setting Priorities for Experimental Studies in Support of Safety Assessments - 19393

Many experiments have been conducted, in both academia and industry, to support the understanding of the disposal of radioactive waste. For the disposal of low-level radioactive waste (LLW) into radioactive waste repositories, it is important to develop an approach to tackle which datasets are able to directly underpin safety assessments, and what future research experiments could address the gaps in this understanding. In this paper, we present an approach to identify which future experiments should be considered to underpin safety assessments for disposals of LLW in a near-surface repository. The approach involves 6-steps: define the disposal problem (e.g. the disposal of LLW in engineered vaults); determine what key processes may affect the disposal of the waste; establish the assumptions underpinning the key processes; determine how sensitive the key process parameters are to variation; determine whether key data are available and assess the quality of that data with respect to the disposal problem; and determine attributes for experiments needed to supply missing key data. We show, in this paper, how this approach can be used to develop a better understanding of C-14 gas generation, under varying degrees of groundwater saturation, for the disposal of LLW into engineered vaults, in the near-surface. Furthermore, we have developed an approach that identifies the types of experiments and their attributes to aid researchers to help select appropriate types of experiments to underpin safety assessments. (authors)

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

Analysis of Exposure during Transportation of Waste to the Nevada National Security Site (NNSS) - 20445

Safety is a priority for the U.S. Department of Energy (DOE) Environmental Management (EM) Nevada Program. This commitment to safety is integrated into requirements and work procedures at DOE sites across the U.S. that generate low-level radioactive waste, mixed low-level radioactive waste, and classified waste that is transported to the Nevada National Security Site (NNSS) for permanent disposal. Generators of this waste are responsible for ensuring it is packaged and transported in a safe and compliant manner. These generators and their contracted commercial carriers must comply with U.S. Department of Transportation (DOT) regulations; the Nevada National Security Site Waste Acceptance Criteria (NNSSWAC); and other applicable federal, state, and local regulations and requirements. This includes packaging and shipping the waste to meet DOT regulatory radiation dose limits to ensure public safety during transportation. NNSS waste generators have a solid safety record for complying with these stringent regulations as demonstrated by the fact that no shipments exceeding DOT dose rate limits were received at the NNSS Area 5 Radioactive Waste Management Complex (RWMC) during FY 2014 through FY 2018. A 2005 study conducted by the Desert Research Institute validated shipments to the NNSS comply with DOT radiation dose limits. In response to recent Nevada stakeholder requests for an updated study, an analysis was conducted to verify and provide evidence that the public continues to be safe from exposure to radioactive waste shipment to the NNSS. Radiation exposure from radioactive waste shipments in transit to the NNSS was evaluated. Three studies were performed: 1. Confirm compliance of waste shipments to the DOT radiation limits using dose rate surveys taken at the generator site and at the disposal site. 2. Estimate the dose to the public from waste shipments using the dosimetry results for disposal site personnel by comparing time of exposure for various individuals/scenarios. 3. Estimate the truck driver dose using the receipt dose rate surveys and time of exposure, and from dosimetry results. Study 1 confirmed compliance with the DOT dose rate limits for a sample of waste shipments (123 of 1,038) received during fiscal year (FY) 2017. Study 2 showed that the average annual radiation equivalent dose for disposal site personnel during FY 2017 was approximately 6.7% [0.415 mSv (41.5 millirem)] of the annual average dose that a person living in the U.S. receives from all sources [6.2 mSv (620 mrem)]. Maximum dose to a member of the public, a person resting/sleeping in an adjacent truck at a rest area to a waste shipment, was 0.0166 mSv (1.66 mrem), which is less than the dose received from a person taking a round trip from the east coast to the west coast of the continental U.S. on an airplane [0.07 mSv (7 mrem) per round trip]. Study 3 showed that the truck driver who made the most shipments of radioactive waste to the NNSS, who drove the most hours (estimated time of exposure 2,520 hours), during FY 2017 had a total dose of 0.15 mSv (15 mrem), which was obtained from their personal dosimeter. The annual dose recorded for disposal site personnel, the dose estimates for the public, and the truck driver dose were all a small percentage of the average radiation dose a person receives from all sources (e.g., background and medical radiation). At these levels, risk should only be described qualitatively. Radiation exposure from radioactive waste shipments to the NNSS were shown to be compliant with the DOT dose rate limits, safe, and very low (i.e., within background levels). (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Special Analysis: 2016-002, Analysis of Cover Erosion and Enhanced Infiltration at Pit 25, TA-54 Area G

The Los Alamos National Laboratory (LANL) generates radioactive waste as a result of various activities. Operational waste is generated from a wide variety of research and development activities including nuclear weapons development, energy production, and medical research. Environmental restoration, and decontamination and decommissioning (D&D) waste is generated as contaminated sites and facilities at LANL undergo cleanup or remediation. The majority of this waste is low-level radioactive waste (LLW) and is disposed of at the Technical Area 54 (TA-54), Area G disposal facility. U.S. Department of Energy (DOE) Order 435.1 (DOE, 2001) requires that radioactive waste be managed in a manner that protects public health and safety, and the environment. To comply with this order, DOE field sites must prepare site-specific radiological performance assessments for LLW disposal facilities that accept waste after September 26, 1988. Furthermore, sites are required to conduct composite analyses that account for the cumulative impacts of all waste that has been (or will be) disposed of at the facilities and other sources of radioactive material that may interact with the facilities.

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DOE OSTI2018

4th Quarter and Annual Transportation Report FY2018

This report satisfies the U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office (NNSA/NFO) commitment to prepare a quarterly summary of waste shipments to the Nevada National Security Site (NNSS) Radioactive Waste Management Complex (RWMC) in Area 5. This report summarizes the fourth quarter of fiscal year (FY) 2018 and serves as an annual report for the following types of shipments: Low-Level Radioactive Waste (LLW); Mixed Low-Level Radioactive Waste (MLLW); Classified Non-Radioactive (CNR) Waste; Classified Non-Radioactive Hazardous (CNRH) Waste; Tabular summaries are provided that include the following: Number and external volume of LLW, MLLW, and CNR/CNRH shipments; Waste generators for LLW, MLLW, and CNR/CNRH shipments to and on the NNSS; Carriers for LLW, MLLW, and CNR/CNRH shipments to and on the NNSS; Waste generator shipments by quarter; Highway routes used by carriers; Incident and accident data applicable to LLW, MLLW, and CNR/CNRH shipments. In this report, shipments are accounted for upon arrival at the NNSS, while disposal volumes are accounted for upon waste burial. Volume reports showing cubic feet (ft 3 ) generated using the Low-Level Waste Information System may vary slightly due to rounding conventions for conversions from cubic meters to cubic feet. Shipments are transported by motor carriers that are either identified on the U.S. Department of Energy (DOE) Motor Carrier Evaluation Program (MCEP) list, have been evaluated in a manner similar to the MCEP process, or are government vehicles. Government vehicles are not evaluated using the MCEP process but are fully compliant with all transportation regulations and requirements.

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