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At least 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Task 12 PV Sustainability - Human Health Risk Assessment Methods for PV, Part 3: Module Disposal Risks

End-of-life management is important for addressing large future photovoltaic (PV) waste volumes and conserving raw materials for use in new PV modules. In regions without regulatory mandates for PV recycling, end-of-life PV modules can be disposed in accordance with general waste laws. Given the use of various metals as raw materials in semiconductor compounds and electrical contacts in commercial PV modules, some stakeholders have raised concerns regarding potential environmental impacts if PV modules are subject to improper disposal instead of being recycled or disposed in sanitary landfills, as is required in most world regions. To evaluate these concerns, screening-level risk assessment methods are developed herein that evaluate potential human health risks from groundwater and surface (air, soil, surface water) exposure pathways. The methods estimate potential impacts from disposal of end-of-life (EOL) PV modules in non-sanitary landfills under the following worst-case conditions: no leachate collection or groundwater monitoring, no liner for preventing leachate migration, uncovered waste, and lack of stormwater management. Examining worst-case conditions allows the exploration of maximum potential risk to attempt to ensure disposal does not increase health risk above regulatory thresholds. Specifically, this report presents an analysis of potential human health risks associated with non-sanitary landfill disposal for three PV technologies, focusing on release of the highest-prioritized chemical element for each: lead (Pb) in crystalline-silicon (c-Si) PV modules, cadmium (Cd) in thin film cadmium telluride (CdTe) PV modules, and selenium (Se) in thin film copper indium selenide (CIS) PV modules. The prioritization of these chemical elements for analysis is based on stakeholder interest. Because the methodology is chemical-specific, the risk assessment results for these chemicals cannot be directly generalized to other chemicals, although the risk assessment methodology can be applied to other chemicals. If the chemicals chosen are indeed the ones presenting greatest risk, then the results herein should represent the upper bound of health risk from exposure to a single constituent.

14 SOLAR ENERGY↗
NASA NTRS2017

Application of GPS to Enable Launch Vehicle Upper Stage Heliocentric Disposal

To properly dispose of the upper stage of the Space Launch System, the vehicle must perform a burn in Earth orbit to perform a close flyby of the Lunar surface to gain adequate energy to enter into heliocentric space. This architecture was selected to meet NASA requirements to limit orbital debris in the Earth-Moon system. The choice of a flyby for heliocentric disposal was driven by mission and vehicle constraints. This paper describes the SLS mission for Exploration Mission -1, a high level overview of the Block 1 vehicle, and the various disposal options considered. The research focuses on this analysis in terms of the mission design and navigation problem, focusing on the vehicle-level requirements that enable a successful mission. An inertial-only system is shown to be insufficient for heliocentric flyby due to large inertial integration errors from launch through disposal maneuver while on a trans-lunar trajectory. The various options for aiding the navigation system are presented and details are provided on the use of GPS to bound the state errors in orbit to improve the capability for stage disposal. The state estimation algorithm used is described as well as its capability in determination of the vehicle state at the start of the planned maneuver. This data, both dispersions on state and on errors, is then used to develop orbital targets to use for meeting the required Lunar flyby for entering onto a heliocentric trajectory. The effect of guidance and navigation errors on this capability is described as well as the identified constraints for achieving the disposal requirements. Additionally, discussion is provided on continued analysis and identification of system considerations that can drive the ability to integrate onto a vehicle intended for deep space.

Anzalone, Evan J.↗
DOE OSTI2019

Natural and Engineered Features Supporting Environmental Performance of Idaho National Laboratory’s Remote-Handled Low-Level Waste Disposal Facility

The Idaho National Laboratory’s (INL’s) Remote-Handled Low-Level Waste (RH LLW) Disposal Facility has been designed and constructed to receive waste generated at the INL site in support of the U.S. Department of Energy (DOE) Office of Nuclear Energy (NE) and Naval Reactors (NR) missions. The facility has been designed to receive legacy RH LLW currently in storage at INL facilities and new waste generated by nuclear research programs. RH LLW to be received at the facility is solid waste consisting of surface contaminated debris; ion exchange resins used to purify cooling and canal water; activated metals generated during reactor core change outs and Naval spent fuel management; and nuclear Research & Development. Disposal of INL's RH LLW poses unique disposal challenges due to high radiation levels (contact rates up to 600 Sv/hr [60,000 Rem/hr]) that require remote handling and adequate shielding for transportation and disposal. The facility has been designed to meet the requirements of DOE Order 435.1 [1], including the all-pathways dose, air pathway dose, inadvertent intruder doses, and radon emissions limits. This paper presents an overview of natural and engineered design features that support the safety case and enhance the environmental performance of the facility. These include location selection, use of reinforced pre-cast concrete vaults; a robust hydraulic drainage system; use of steel waste canisters for waste disposal; the facility monitoring system; facility layout; and crediting waste forms. The facility performance assessment (PA) [2] developed to meet the requirements of DOE Order 435.1 “Radioactive Waste Management” credits each of these protective features. Releases from waste forms disposed of at this facility are limited by corrosion of the steel waste canisters which will ultimately allow contact with infiltrating water followed by transport of radionuclides from the vault system. The steel waste canisters were credited for their ability to limit water contact with the waste based on the demonstrated ability of the reinforced pre-caste concrete vaults to provide long-term structural protection of the steel waste canisters. Verification of hydraulic and concrete performance was conducted through laboratory data, field infiltration tests supported by a robust monitoring system, and numerical modeling. Releases into the vault system from activated metals are based on site-specific corrosion data. Radionuclide transport from the vault system from all waste forms is based on site-specific climatological, hydrologic, and stratigraphic data. At INL, the groundwater pathway historically and appropriately has received the most attention. By crediting aspects of the natural system, the engineered vault system, and the waste, estimated radiologic doses via the groundwater pathway are minimal. Air pathway doses were reduced by differentially crediting corrosion of aluminum and stainless steel activated metals resulting in the pathway being screened out of the PA. Groundwater and inadvertent intruder doses were reduced through selective facility layout. This paper provides an overview of the system-wide protective features incorporated into the facility design along with an extensive reference list to supporting technical papers and analyses that provide data and interpretation.

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DOE OSTI2021

Modeling and Analysis of the Transport and Disposal of Beryllium Moderator Blocks and Greater than Class C (GTCC) Waste

Radioactive waste in the United states is categorized based on its source, radioactivity, and security risk. The categorization method employed by the Nuclear Regulatory Committee (NRC) for low-level radioactive waste is not currently applied to any waste generated by the Department of Energy (DOE) or disposed of in DOE facilities. As a result, there is a large volume of DOE-generated waste with characteristics similar to the NRC’s “Greater than Class C” (GTCC) waste category which presently do not have a path for long-term disposal. Much of this waste cannot undergo the standard commercial disposition process due to it being categorized as Transuranic (TRU) waste under DOE guidelines, due to elevated concentrations of key fission products. Possible solutions to this dilemma are explored in the Environmental Impact Statement for the “Disposal of Greater-Than-Class-C Low Level Radioactive Wave” (EIS-0375). This paper analyzes several EIS possible paths for disposal for this “orphaned” waste. One example that highlights this categorization issue is the spent beryllium cladding that has been extracted from the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) throughout its operational lifetime. These beryllium blocks surround the reactor’s main chambers and components and serve as neutron moderators. This paper will use this particular waste form to analyze the economic and technological viability of transporting and storing this material under the storage and transportation criteria of the Waste isolation Pilot Plant (WIPP), which was deemed the most feasible disposition path according to the EIS. The example of this waste form used in this paper that highlights this categorization issue is the spent beryllium cladding extracted from Idaho National Laboratory’s (INL) Advanced Test Reactor (ATR). These beryllium blocks surround the reactor’s components and serve as neutron moderators, and thus have accumulated high concentration of high-activity transuranic isotopes. This paper analyzed the viability of transporting and storing this material under the storage and transportation criteria of the five primary disposition paths covered in EIS-0375. An array of calculations was carried out to assess the viability of the various disposition paths for the beryllium shipments as well as other waste shipments that fall within the GTCC category. Modeling with MCNP 6.2 was conducted to determine whether the beryllium blocks could be safely stored and transported within a 72-B cask; the standard shipping container for remote-handled, transuranic waste, while also meeting regulatory limits at various disposition paths. A cost analysis of the transportation and long-term disposal paths mentioned in the EIS was also carried out using available data and information from similar waste shipments. Lastly, a geochemical analysis of the various geological repository discussed in the EIS was also carried out using the Geochemists Workbench Release 14. Long-term disposal of the beryllium blocks at the Waste Isolation Pilot Plant (WIPP) proved to be the most cost-effective long-term disposition option of the ones considered in the EIS. A dose rate calculation at both contact and remote-handling distances indicate that the analyzed beryllium shipments should not exceed the exposure limits at any of the considered locations. Greater-than-class-C waste has been left in a regulatory state of limbo for years, resulting in backlogs of inventory across several research sites in the United States. Due to its high activity and presence of transuranic isotopes, it is imperative to ensure that it remains inaccessible and sequestered both in its short-term interim as well as a long-term geologic time scale. The information and assessments done in the paper could potentially serve as a reference for any future shipments of this waste form at the WIPP facility as well as other disposition paths that may be considered in the future.

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DOE OSTI2021

Annual Summary Report for the Remote-Handled Low-Level Waste Disposal Facility—FY 2020

This Fiscal Year (FY) 2020 annual summary report documents the continued adequacy of the performance assessment (PA), the composite analysis (CA) and associated operating disposal-authorization statement (ODAS) technical basis documents for the Remote Handled (RH) Low-Level Waste (LLW) Disposal Facility at Idaho National Laboratory. Annual review of the adequacy of the PA and CA for the RHLLW Disposal Facility ensures that conclusions of the analyses remain valid in accordance with requirements of Department of Energy (DOE) Order 435.1 Change 1, “Radioactive Waste Management.” In FY 2020, no significant operational changes or other activities occurred that would cause deviation from the assumptions in the PA and CA pertaining to disposal geometry, verification of waste characteristics, tracking disposal inventories against total limits, facility closure design, or institutional controls. Fifteen total waste-canister shipments were received at the RHLLW Disposal Facility, and 15 total waste canisters were emplaced.

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DOE OSTI2013

The Texas Solution to the Nation's Disposal Needs for Irradiated Hardware - 13337

The closure of the disposal facility in Barnwell, South Carolina, to out-of-compact states in 2008 left commercial nuclear power plants without a disposal option for Class B and C irradiated hardware. In 2012, Waste Control Specialists LLC (WCS) opened a highly engineered facility specifically designed and built for the disposal of Class B and C waste. The WCS facility is the first Interstate Compact low-level radioactive waste disposal facility to be licensed and operated under the Low-level Waste Policy Act of 1980, as amended in 1985. Due to design requirements of a modern Low Level Radioactive Waste (LLRW) facility, traditional methods for disposal were not achievable at the WCS site. Earlier methods primarily utilized the As Low as Reasonably Achievable (ALARA) concept of distance to accomplish worker safety. The WCS method required the use of all three ALARA concepts of time, distance, and shielding to ensure the safe disposal of this highly hazardous waste stream. (authors)

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DOE OSTI2013

Geological Disposal Concept Selection Aligned with a Voluntarism Process - 13538

The UK's Radioactive Waste Management Directorate (RWMD) is currently at a generic stage in its implementation programme. The UK site selection process is a voluntarist process and, as yet, no communities have decided to participate. RWMD has set out a process to describe how a geological disposal concept would be selected for the range of higher activity wastes in the UK inventory, including major steps and decision making points, aligned with the stages of the UK site selection process. A platform of information is being developed on geological disposal concepts at various stages of implementation internationally and, in order to build on international experience, RWMD is developing its approach to technology transfer. The UK has a range of different types of higher activity wastes with different characteristics; therefore a range of geological disposal concepts may be needed. In addition to identifying key aspects for considering the compatibility of different engineered barrier systems for different types of waste, RWMD is developing a methodology to determine minimum separation distances between disposal modules in a co-located geological disposal facility. RWMD's approach to geological disposal concept selection is intended to be flexible, recognising the long term nature of the project. RWMD is also committed to keeping alternative radioactive waste management options under review; an approach has been developed and periodic reviews of alternative options will be published. (authors)

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DOE OSTI2012

Prairie Island Nuclear Station Spent Filter Processing for Direct Disposal - 12333

This paper will discuss WMG's filter processing experience within the commercial nuclear power industry, specifically recent experience processing high activity spent filters generated by Xcel Energy's Prairie Island Nuclear Station (Prairie Island), located in Welch, MN. WMG processed for disposal eighty-four 55-gallon drums filled with varying types of high activity spent filters. The scope of work involved characterization, packaging plan development, transport to the WMG's Off-Site Processing location, shredding the filter contents of each drum, cement solidifying the shredded filter material, and finally shipping the solidified container of shredded filter material to Clive, Utah where the container was presented to EnergySolutions Disposal site for disposal in their Containerised Waste Facility. This sequence of events presented in this paper took place a total of nine (9) times over a period of four weeks. All 1294 filters were successfully solidified into nine (9) -WMG 142 steel liners, and each was successfully disposed of as Class A Waste at EnergySolutions Disposal Site in Clive, Utah. Prairie Island's waste material was unique in that all its filters were packaged in 55-gallon drums; and since the station packaged its filters in drums it was much easier to develop packaging plans for such a large volume of legacy filters. For this author, having over 20-years of waste management experiences, storing and shipping waste material in 55-gallon drums is not immediately thought of as a highly efficient method of managing its waste material. However, Prairie Island's use of 55-gallon drums to store and package its filters provided a significant advantage. Drums could be mixed and matched to provide the most efficient processing method while still meeting the Waste Class A limits required for disposal. (author)

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DOE OSTI2016

Safety Case Considerations for Deep Borehole Disposal of Cs/Sr Capsules - 16294

The U.S. Department of Energy Office of Nuclear Energy (DOE-NE) performed an assessment of disposal options that recommended the consideration of deep borehole disposal of smaller DOE-managed waste forms, such as cesium (Cs) and strontium (Sr) capsules. To assess the feasibility of the deep borehole disposal concept for Cs/Sr capsules, safety case considerations are identified and examined. A safety case includes quantitative (e.g., safety assessments) and qualitative information related to both pre-closure (operational) and post-closure safety. For deep borehole disposal of Cs/Sr capsules, pre-closure safety considers potential hazards associated with waste package surface handling and downhole emplacement activities; post-closure safety considers scenarios for long-term radionuclide transport to the biosphere. A preliminary list of qualitative indicators of pre-closure and post-closure safety is presented. Research, development, and demonstration (RD and D) activities that can provide a quantitative basis for these indicators are discussed. In particular, DOE-NE has initiated a Deep Borehole Field Test, using surrogate test packages without radioactive waste, to further investigate various aspects of site characterization, deep drilling, and waste package handling and emplacement that would be needed for a full-scale disposal facility for Cs/Sr capsules or other DOE-managed waste forms. Finally, preliminary results from pre-closure hazard analyses and post-closure performance assessment (PA) calculations are presented as examples of supporting information for the quantitative safety case considerations. These preliminary results suggest that a favorable safety case can be developed for deep borehole disposal of Cs/Sr capsules. (authors)

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DOE OSTI2016

Development of a Universal Canister for Disposal of High-Level Waste in Deep Boreholes - 16482

The mission of the United States Department of Energy's (DOE's) Office of Environmental Management is to complete the safe cleanup of the environmental legacy brought about from five decades of nuclear weapons development and government-sponsored nuclear energy research. Some of the wastes that must be managed have been identified as good candidates for disposal in a deep borehole in crystalline rock. In particular, wastes that can be disposed of in a small package are good candidates for this disposal concept. A canister-based system that can be used for handling these wastes during the disposition process (i.e., storage, transfer, transportation, and disposal) could facilitate the eventual disposal of these wastes. Development of specifications for the universal canister system will consider the regulatory requirements that apply to storage, transportation, and disposal of the capsules, as well as operational requirements and limits that could affect the design of the canister (e.g., deep borehole diameter). In addition, there are risks and technical challenges that need to be recognized and addressed as Universal Canister system specifications are developed. This paper provides an approach to developing specifications for such a canister system that is integrated with the overall efforts of the DOE's Used Fuel Disposition Campaign's Deep Borehole Field Test and compatible with planned storage of potential borehole candidate wastes. (authors)

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DOE OSTI2019

Management and Disposal of U.S. Department of Energy Spent Nuclear Fuel - 19133

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. In accordance with this mandate, the NWTRB reviewed the U.S. Department of Energy's (DOE) efforts to manage the inventory of spent nuclear fuel (SNF) that is under its control (DOE SNF) at several facilities around the country: the Hanford Site in Washington, the Idaho National Laboratory (INL) in Idaho, the Savannah River Site (SRS) in South Carolina, and the Fort St. Vrain independent spent fuel storage installation (ISFSI) in Colorado. While disposal of SNF and high-level radioactive waste (HLW) in a deep geologic repository remains the ultimate objective of the DOE nuclear waste management program, there is significant uncertainty about when such a repository will be constructed in the United States. Until disposal occurs, it is essential to manage DOE SNF in a way that will facilitate its eventual disposal, and it is also important to improve understanding of processes related to packaging and storage of the SNF that could affect its future transportation and disposal. The NWTRB's review, which was a multi-year effort, was documented in a report to Congress and the Secretary of Energy and is summarized here. The NWTRB reviewed the quantities and characteristics of DOE SNF at each of the four sites. It also examined DOE packaging and storage activities and plans at each of the sites. The NWTRB highlighted three main issue areas in its review. First, the review identified issues related to managing the aging of DOE SNF and the facilities used to store the DOE SNF. Second, the review addressed issues related to packaging of stored non-naval DOE SNF into a standard canister. Third, the NWTRB assessed issues that could affect disposal of DOE SNF if DOE continues to evaluate a range of repository settings. Based on the information and findings developed as part of its review, the NWTRB made six recommendations to Congress and the Secretary of Energy related to aging management, packaging, and disposal of DOE SNF. DOE has begun to address some of the NWTRB recommendations. (author)

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

Erosion Challenges at the L-Bar Disposal Site - 19561

The L-Bar, New Mexico, Disposal Site is located in the northeast corner of Cibola County, 10 miles north of Laguna, and was the former site of a uranium mill and underground mine. The mill operated from 1977 to 1981 where a total of 1.9 x 10{sup 6} tonnes (2.1 million tons) of ore was processed. Solid and liquid byproduct, or tailings, from the milling process were impounded behind a dam constructed of native weathered Mancos Shale, which is a predominant geologic formation in the area. The tailings were encapsulated in place, and the resulting 40.5-hectare (100-acre) engineered disposal cell was completed in 2000. The 299-hectare (738-acre) Uranium Mill Tailings Radiation Control Act Title II site was transferred to the US Department of Energy (DOE) Office of Legacy Management under a US Nuclear Regulatory Commission general license in 2004. During reclamation activities, channels were designed and constructed into the surrounding weathered shale to protect the disposal cell from high-precipitation events. Due to the highly erodible soils and anticipated sediment deposition into the diversion channels, a sediment trap was also excavated. By excavating the channels and sediment trap, the local base elevation was altered, which exacerbated erosional forces. Recontouring surrounding drainage basins during the reclamation activities also promoted erosion by reducing natural rock armoring and vegetation that aids in soil stability. To compound the erosion issue, the L-Bar site is susceptible to short-duration, high-intensity, localized convective storms. Because the local geomorphology includes soils consisting of weathered shale, these precipitation events are not conducive to absorption into the soils, but rather to sheet flows that follow topography and concentrate in lower elevation areas where flow volumes and velocities increase. These factors result in the formation of deeply incised gullies and promote soil piping, which is an important geomorphic process in the widening of arroyos and the advancement of head-cutting, evident at the L-Bar site and surrounding areas. At the first annual inspection by DOE in 2005, it was noted that extensive erosion was occurring upgradient of the sediment trap. DOE determined that the design of the site's drainage system was the cause of extensive erosion. It is believed that by lowering the base elevation of the local drainage system through excavation of the sediment trap, the geomorphic response common to fluvial systems in a semiarid environment has increased the incision and remobilization of sediment downstream. Over time, these sediments would be deposited in the channels, which are designed to divert runoff away from the disposal cell, effectively limiting their capacities. The development of alluvial fans on one side of the channel directs flows to the opposite side of the channel, presenting the risk of cutting into the side slopes of the disposal cell. In addition, the upstream migrating gullies could intersect access roads and create hazards for adjacent stakeholders, including their grazing livestock. Current estimates conclude that potential offsite impacts could occur within the next 20 years, with gully migrations of up to 19 meters (63 feet) per year. In 2009, several erosion-control structures were constructed to reduce runoff velocities and ease the elevation differential created by the construction of the sediment trap and diversion channels. The first measurable storm events after construction occurred in August and September 2011, where one structure washed out and another structure was bypassed when runoff breached an earthen berm. DOE has conducted site assessments, continues to monitor erosion, and has applied lessons learned in the process of evaluating options to repair or modify the structures to stabilize the site and prevent potential short-term damage to adjacent properties as well as long-term damage to the disposal cell. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Presentation on the INL Remote-Handled Low-Level Waste Disposal Facility FY-2023 Annual Summary Report

The abstract below is from the report INL/RPT-24-76103. The powerpoint presentation contains information taken from the report. This Fiscal Year (FY) 2023 annual summary report (ASR) documents the continued adequacy of the performance assessment (PA), the composite analysis (CA) and associated operating disposal-authorization statement (ODAS) technical basis documents for the Remote Handled (RH) Low-Level Waste (LLW) Disposal Facility at Idaho National Laboratory. Annual review of the adequacy of the PA and CA for the RHLLW Disposal Facility ensures that conclusions of the analyses remain valid in accordance with requirements of Department of Energy (DOE) Order 435.1, “Radioactive Waste Management.” In FY 2023, no significant operational changes or other activities occurred that would cause deviation from the assumptions in the PA and CA pertaining to disposal geometry, verification of waste characteristics, tracking disposal inventories against total limits, facility closure design, or institutional controls. Sixteen total waste-canister shipments were received at the RHLLW Disposal Facility, and 15 total waste canisters were emplaced.

12 - MGMT OF RADIOACTIVE AND NON-RADIOACTIVE WASTE↗
DOE OSTI2017

Assessment of Aquifer Baseline Conditions at the Idaho National Laboratory Remote-Handled Low-Level Waste Disposal Facility

This document provides an analysis of radiologic concentrations in the aquifer and vadose zone near Idaho National Laboratory’s (INL’s) Remote-Handled Low-Level Waste (RH-LLW) disposal facility. This document identifies pre-existing sources of radiologic contaminants that could be transported to the aquifer near the RH-LLW disposal facility based on releases from nearby facility operations. It contains a summary of radionuclide concentration data in the upstream perched water and in the aquifer upstream and downstream of the RH LLW disposal facility in order to establish known variability from these pre existing radiologic sources. Using this historical data allows meaningful aquifer monitoring targets to be established for the RH-LLW disposal facility monitoring system (i.e., vadose zone wells and aquifer wells) to allow potential releases from the RH-LLW disposal facility to be distinguished from the pre existing sources of contaminants that are likely to be detected in the monitoring system.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Approaches to consider covers and liners in a low-level waste disposal facility performance assessment

On-site disposal cells are in use and being considered at several USDOE sites as the final disposition for large amounts of waste associated with cleanup of contaminated areas and facilities. These disposal cells are typically regulated by States and/or the USEPA in addition to having to comply with requirements in DOE Order 435.1, Radioactive Waste Management. The USDOE-EM Office of Site Restoration formed a working group to foster improved communication and sharing of information for personnel associated with these Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) disposal cells and work towards more consistent assumptions, as appropriate, for technical and policy considerations related to performance and risk assessments in support of a Record of Decision and Disposal Authorization Statement. One task completed by the working group addressed approaches for considering the performance of covers and liners/leachate collection systems in the context of a performance assessment (PA). A document has been prepared which provides recommendations for a general approach to address covers and liners/leachate collection systems in a PA and how to integrate assessments with defense-in-depth considerations such as design, operations and waste acceptance criteria to address uncertainties. Specific information and references are provided for details needed to address the evolution of individual components of cover and liner/leachate collection systems. This information is then synthesized into recommendations for best practices for cover and liner system design and examples of approaches to address the performance of covers and liners as part of a performance assessment of the disposal system.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

A National Disposal Facility for Radioactive Waste for Iraq - 16610

Radioactive waste resulted in the past in Iraq from a number of nuclear activities and facilities all of them seriously damaged or destroyed during the Gulf war. The task of decommissioning such facilities and managing the resulting waste is being supported by the International Atomic Energy Agency (IAEA), the European Union (EU), and the United States (US). A national policy for radioactive waste management for Iraq has been drafted by the Ministry of Science and Technology (MoST); a draft strategy for radioactive waste management implementation is in preparation. In this framework, Iraq is considering locating a radioactive waste disposal facility at the Al-Tuwaitha site, near the capital city of Bagdad. In the framework of its Instrument for Nuclear Safety Cooperation the EU has recently started a cooperation project named 'Feasibility Study, Basic Design, and Engineering Design of an Engineered Radioactive Waste Disposal Facility' for Iraq (Project IQ4.01/11). The project aims at producing the design of a repository for the radioactive waste resulting from the decommissioning activities and from the continuing use of radioisotopes in medicine and the oil and gas industry in the country. The contract for this cooperation project was awarded by the European Commission in April 2015 to the consortium of two international engineering companies, Nukem Technologies Engineering Services GmbH and DBE Technology GmbH, both of Germany, and Javys a.s., the national waste management agency of Slovakia. The planned Iraqi near-surface repository is constrained by the complex security conditions in the country. This has led to the decision of using whenever possible the Al-Tuwaitha site, were most of the waste is located, as the repository location. The project work will therefore focus on assessing whether and which part of the waste expected to result from the decommissioning and remediation activities is amenable for surface disposal in an appropriately engineered facility. In addition, careful review of the site characteristics shall provide enough elements to justify and validate the political decision of disposing of the waste in Al Tuwaitha. Thereafter, the project work will focus on the conceptual and later the engineering design of the repository. Finally, a Safety Analysis will provide the basis for regulatory decisions about the further steps for realization of the Iraqi final disposal facility. (authors)

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DOE OSTI2018

Global Review of Site Suitability Conditions for the Geological Disposal of Radioactive Waste - 18136

The long-term safety of radioactive waste disposal is based on two key principles: (i) containment of the waste until the radioactivity has decreased to negligible levels, and (ii) the isolation of the waste packages in stable conditions that are conducive to maintaining the integrity of the containment for as long as required. In this paper, we review disposal site suitability criteria based on international best practices from geological disposal studies in crystalline and argillaceous rocks. Adopting social acceptability criteria in addition to safety-related criteria has been shown to be pivotal in obtaining community support. The reviewed criteria may be used as a guide to develop future site selection criteria for disposal of Australian intermediate level waste streams that are incompatible with surface disposal. (authors)

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DOE OSTI2018

Integration of Models for the Hanford Integrated Disposal Facility Performance Assessment - 18541

The Department of Energy Office of River Protection and its contractors have performed a performance assessment for the near-surface disposal of low-level and mixed low-level waste at the Hanford Integrated Disposal Facility. The long-term performance of the Hanford Integrated Disposal Facility to be protective of human health and the environment was evaluated under the requirements of United States Department of Energy Order 435.1, Radioactive Waste Management. Computer simulations were performed to evaluate whether or not the disposal facility would comply with the performance objectives specified in the order. The evaluation was performed using numerical models to simulate source term releases from vitrified and cement-based waste forms. Source term releases were subsequently transported through the facility into the natural system beneath the facility (comprised of an 85-meter thick vadose zone and thinner but highly conductive saturated zone overlying basalt) to a point of compliance 100-meters downstream from the disposed waste. Due to the differing scales in the finite difference models developed for the source terms and those developed for the natural system, numerical models for source term release and natural system flow and transport were not directly coupled. Instead, the output from the source term simulations were used as input to the natural system flow and transport simulations. The decoupling of the modeled systems makes it difficult to explore synergies and investigate the impact of parameter uncertainties. In order to explore system synergies and evaluate parameter uncertainty, an integrated system model was developed that includes source term release models, natural system transport models, and dose calculations. This paper will describe how the numerical models were used to develop abstractions that could be incorporated into the integrated system level model that was then used to explore system synergies and parameter uncertainties. (authors)

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