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At least 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Developments in the Regulatory Framework of Interim Storage of Spent Nuclear Fuel (SNF) in Germany - 17374

According to article 6 of the German Atomic Energy Act, storage of nuclear fuel requires a license, granted by the competent authority in this field, which has been the Federal Office of Radiation Protection (BfS) until July 2016 and currently is the Federal Office for the Safety of Nuclear Waste Management (BfE). A first license was granted in 1983 for storage of spent nuclear fuel (SNF) and vitrified high level waste (HAW) at the interim storage facility in Gorleben. This license was reviewed in 1995. Dry Interim storage at the NPP sites in its current form started in 2002 in the interim storage facility next to the NPP Lingen. Since that time at each site of an operational NPP storage facilities were licensed and erected. Thus additionally to the three central storage facilities (Ahaus, Gorleben and Rubenow) there are now 12 storage facilities onsite the NPPs. All of these facilities use dry storage in metallic dual purpose casks (DPCs). The actual storage licenses for SNF and the HAW (which is stored in Gorleben and Rubenow) are limited to 40 years after closing the transport and storage cask. The first license to expire will be the storage license for the interim storage facility in Gorleben in the year 2034. The German 'Programme for the safe and responsible management of spent fuel and radioactive waste' expects to take the disposal facility into operation in the year 2050. Thus necessary preparations for interim storage till that time have to be taken on the side of the regulator. In the German Atomic Energy Act precautions have already been taken and a consulting of the German parliament (Bundestag) is mandatory if inevitable events would require an extension of currently licensed interim storage period. In the year 2016, the regulatory body in Germany was given a new structure. The BfS was formerly competent authority in the field of radiation protection since 1989. It had competencies for ionizing and non-ionizing radiation protection (e.g. mobile phone radiation, high voltage power lines and the effects of electric fields), licensing storage of spent nuclear fuel and as the operator of facilities for final disposal. Now there is a new structure with two Federal Offices (BfS and BfE) and a federal company for final disposal (BGE). The BfE is responsible for regulation in the field of nuclear disposal since 30.07.2016. So the package design approval for DPCs and the storage licenses for SNF are now granted by this office. The search for a repository site will be coordinated there as well. The site selection, construction and operation of the repository will be in the responsibility of BGE. The parts of the former BfS dealing with recovery of the waste from Asse (a former salt mine used for disposal research) and the construction of the repository Konrad (for low and medium level radioactive waste) will be transferred into that company. It is planned to incorporate the German company for construction and management of waste disposal facilities (DBE) which is owned by the German utilities as well. The BfS will focus on the scientific foundations and further advancement of radiation protection. (authors)

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DOE OSTI2017

Use of Nuclear Divers in Decommissioning of Spent Fuel Pools/Ponds in the United Kingdom - 17431

Magnox Ltd. (Operated by the Cavendish Fluor Partnership) has initiated decommissioning of spent fuel pools/ponds utilizing divers. This decommissioning technique is being employed to disassemble and size reduce underwater equipment and furniture, as well as the collection of sludge and debris prior to draining of the pool. This technique has proven to be highly effective at reducing the radiological exposure to the workforce over previously implemented methods and is expected to significantly reduce overall decommissioning durations and costs. The decommissioning of the UK Nuclear Decommissioning Authority's (NDA) Dungeness A power station spent fuel ponds was initiated in 2015 to eliminate the mobile hazards and prepare the facilities for entry into a Care and Maintenance period. This dual reactor site has two spent fuel ponds each containing 1000 m{sup 3} of water, with the fuel removed since April 2012, which will utilize divers to remove solid wastes from the ponds prior to drain down. This technique has overcome many challenges to implementation including regulatory approval and high airborne contamination. The use of divers for decommissioning was a new technique for the Magnox Sites and required early engagement with the UK Office for Nuclear Regulation (ONR) and the Health and Safety Executive (HSE). The use of plasma arc cutting underwater required the pond area to be classified as an airborne contamination area. The implementation of local ventilation has controlled this hazard. The initial demonstration dives at Dungeness A were completed in April 2016 and the decommissioning dives are expected to be completed in March 2017. This is a substantial improvement to the project schedule and will allow the project completion 5 1/2 years ahead of the Licence Condition milestone. This technique is planned to be implemented at two further NDA Magnox power stations over the next three years. This paper provides the accomplishments and lessons learned to date. (authors)

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DOE OSTI2015

Repository planning for spent nuclear fuel and high-level radioactive waste: insights from U.S.. and international programs - 15638

For decades, the United States and other nations with nuclear programs have been planning for permanent disposition of spent nuclear fuel and high-level waste, to address the increasingly difficult problem of storing these materials for the long term. These plans are complicated by issues ranging from technological factors to regulatory approaches and public concerns about health and environmental protection. In its 2012 report, the Blue Ribbon Commission (BRC) on America's Nuclear Future identified a number of recommendations for creating a safe, long-term solution to the nation's problem of managing and disposing of its spent fuel and high-level radioactive waste. These include a recommendation that the U.S. Environmental Protection Agency (EPA) revise its standards for a high-level waste repository. The EPA is currently reviewing and synthesizing literature relevant to such standards, including: (1) existing national and international standards and guidelines for repositories; and (2) benefits and barriers to such standards, including limitations related to current technologies, as well as siting, licensing, and construction processes. This paper highlights findings of this literature review and synthesis. More than 90 countries, from Albania to Vietnam and Yemen, were identified as potential sources of relevant information based on existing nuclear programs or consideration of such programs to address future energy needs. Pursuant to the BRC recommendations, the U.S. Department of Energy (DOE) has compiled extensive information resources relevant to spent fuel and radioactive waste repositories in the Centralized Used Fuel Resource and Information Exchange (CURIE) database developed by Oak Ridge National Laboratory. Further valuable sources of information include annual proceedings of recent Waste Management Symposia, which provide insights into recent trends and progress across various national and international programs. Recent literature from a number of countries, including the United States and Canada, and the United Kingdom, Finland, Sweden, France, Germany, and other countries in Western Europe, as well as other regions including Australia, indicates that consent-based siting has emerged as a dominant theme. In addition to effective siting processes, key program needs identified in the literature include regulatory standards and performance context, as well as reliable technologies and engineered systems, such as for deep drilling and assured safe containment of these radioactive materials extending into the very long term. (authors)

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DOE OSTI2016

Developing a New National Programme and Implementation Plan for the Management and Disposal of Spent Fuel and Radioactive Wastes in Romania - 16391

The European 'Waste Directive' (2011/70/Euratom) required each Member State to report by August 2015 on their National Programme for management of spent fuel and radioactive wastes. In Romania, the Nuclear Agency (ANDR) was responsible for preparing the National Programme report, and this was done in a step-wise manner that involved the regulators and waste producers. The starting point for the process was an assessment of existing policy against the evolving situation in the nuclear sector in the country, most notably the decision to progress with the construction of two new CANDU reactors. The final agreed National Programme report submitted to the European Commission describes the activities currently undertaken to manage spent fuel and radioactive wastes in Romania. The report also sets out, at a high-level, the additional activities that will need to be taken in the future (and an indicative timeline), including those steps that will be required to implement a new surface repository for short-lived wastes, and a geological repository for spent fuel and long-lived wastes. Additional, on-going work is intended to lead to a revision of Government policy and the development of a more detailed implementation strategy, underpinned by a programme of R and D and robust financing plans. (authors)

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DOE OSTI2016

A Study on the Temperature Correlation between a Surface of Dry Storage Canister and Spent Fuel Clad - 16446

Analysis of temperature correlation between dry canister surface and spent fuel cladding is performed in this study. The result shows that the spent fuel cladding temperature is possibly estimated using canister surface temperature in normal condition and the result of estimation is depended on analysis model. Two analysis models are designed by using a hypothetical spent fuel model and thermal analysis for the models is performed by using CFX(v11.0) code. (authors)

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DOE OSTI2016

A Novel Approach for the Study of Corrosion and Ageing of Spent Nuclear Fuel - Looking Inside the box; From a Distance - 16467

The management and safe long-term storage of fuels and waste products is one of the most important challenges that faces the commercial nuclear industry. Understanding how these materials behave and evolve during wet and dry storage will then have significant impact on our ability to understand and predict the long-term impact of storing spent nuclear fuel. In many research laboratories the infrastructure required for the safe handling and examination of spent nuclear fuel materials is simply not available, thereby limiting the number of research organisations able to contribute to this field of nuclear research. The current article details a novel approach being developed to provide in-situ studies of corrosion and ageing in uranium-based systems relevant to the UK nuclear industry but without the need for hands on experimentation with real spent fuel materials. (authors)

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DOE OSTI2017

Impact of grid growth on PWR spent fuel pool criticality analysis

Zircaloy based grids tend to grow with increasing fuel burnup. Grid growth increases the fuel pin pitch, which can increase fuel reactivity in the spent fuel pool. The amount of grid growth is dependent on the grid material. Zircaloy-4 grids tend to grow more than modern alloys such as Westinghouse Zirlo{sup TM} or AREVA M5{sup TM}, that have been developed, in part, to reduce irradiation growth. Grid growth has been included in the recent criticality analysis of the North Anna and Indian Point Unit 2 spent fuel pools. Grid growth is temperature dependent so the grid growth is not uniform over the axial length of the fuel. Above the active fuel is an Inconel grid which grows insignificantly. It has been conservatively assumed that the fuel pin pitch increases uniformly at all axial planes consistent with the maximum grid growth of any grid. Although this may seem overly conservative, the reactivity in the spent fuel pool for heavily burned fuel is dominated by the top few feet where the maximum grid growth occurs. At 50 GWd/MTU the grid growth is approximated as 0.47% for the Indian Point Unit 2 analysis. Assuming a uniform increase in pitch of 0.47% for 50 GWd/MTU fuel, the pool reactivity increases about 0.003 in k or about 0.6 GWd/MTU. (authors)

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DOE OSTI2018

Preliminary Evaluation of Removing Spent Nuclear Fuel From Shutdown Sites - Fort Calhoun Site Visit - 18048

This is a technical paper that does not take into account contractual limitations under the Standard Contract for Disposal of Spent Nuclear Fuel and/or High-Level Radioactive Waste (10 CFR Part 961). Under the provisions of the Standard Contract, DOE does not consider spent nuclear fuel in multi-assembly canisters to be an acceptable waste form, absent a mutually agreed to contract amendment. To the extent discussions or recommendations in this paper conflict with the provisions of the Standard Contract, the Standard Contract provisions prevail. An updated evaluation of removing spent nuclear fuel (SNF) from 14 shutdown nuclear power plant sites was conducted during 2017. The major update since 2016 was the addition of the recently shutdown Fort Calhoun site to the evaluation. The Fort Calhoun site is located on the western shore of the Missouri River in Washington County in eastern Nebraska, about 31 km north of Omaha, Nebraska. Fort Calhoun has been shut down since October 24, 2016 and final removal of SNF from the reactor vessel was completed on November 13, 2016. The site visit to Fort Calhoun occurred in May 2017 and involved meetings with the Fort Calhoun staff and the Union Pacific Railroad. Participants in the site visit included the Federal Railroad Administration, Pahrump Paiute Tribe, Prairie Island Indian Community, Nebraska State Patrol, Nebraska Department of Health and Human Services, Iowa Department of Transportation Office of Rail Transportation, Iowa Department of Transportation Office of Motor Vehicle Enforcement, and the Council of State Governments-Midwest. The Fort Calhoun site was found to have two transportation mode options for the removal of SNF, rail and barge. In the case of rail, an onsite rail spur could be reinstalled from the existing Cargill industrial spur that runs through the Fort Calhoun site, or an onsite trans-load onto the Cargill industrial spur could be performed. In 2006, a barge was used to ship steam generators, a pressurizer, and a reactor vessel head to the Fort Calhoun site; consequently, barge transport of SNF offsite is potentially an option. (authors)

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DOE OSTI2018

The DISTINCTIVE University Consortium: AGR, Magnox and Exotic Spent Fuels - 18345

The Engineering and Physical Sciences Research Council (EPSRC) sponsored consortium Decommissioning, Immobilisation and Storage Solutions for Nuclear Waste Inventories (DISTINCTIVE) is contributing to the development of skilled cross-disciplinary scientists and engineers with the knowledge and experience required to develop engineering solutions tailored for application within radiologically contaminated sites. Of the four themes addressed by the DISTINCTIVE consortium, the AGR (Advanced Gas-Cooled Reactor), Magnox and Exotic Spent Fuels theme considers the UK's diverse spent nuclear fuel inventory and the preferred options for disposal; this includes the retrieval of fuel from current storage facilities and the repackaging options available. Specifically, the research is concerned with AGR, Magnox and so-called 'Exotic' spent fuels; the goal being to increase knowledge and mechanistic understanding of the processes affecting long-term management and mitigation of any potential risks. (authors)

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DOE OSTI2016

Fission Gases in Spent Fuel Pool Criticality Analysis

Historically all fission products, including fission gases have been included in the criticality analysis of many spent fuel pools (SFP). For transport casks ISG-8 Rev. 3 states, 'Credit for neutron absorbing isotopes other than those identified in Tables 1 and 2 should be accompanied by assurance that such isotopes are non-volatile, and non-gaseous,..' Recent questions from the NRC have challenged using fission gases in spent fuel pool criticality analyses, noting that the time the fuel is contained in the spent fuel pool can be long. This paper establishes a conservative approach for using some of the fission gases in the criticality analysis. Calculations have been performed for Indian Point Unit 2 to determine the impact of the fission gas release. The calculations have been run with the noble gases reduced by 32%, the halogens reduced by 10% and the Rb reduced by 44%. At 43 GWd/MTU, the impact of reducing the isotopes described here is only 0.0014 in k. (authors)

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DOE OSTI2019

Update on Development of a U.S. Rail Transport Capability for Spent Nuclear Fuel and High-Level Waste - 19092

This paper provides an overview of the progress to date, and discussion of the path forward, related to designing, fabricating and testing prototype railcars that will comply with the safety standard S-2043. This standard was developed by the Association of American Railroads (AAR) specifically for railcars used to transport High-Level Radioactive Material (HLRM). AAR defines the term HLRM to include both spent nuclear fuel (SNF) and high-level radioactive waste (HLW). DOE is in the process of developing and testing prototype railcars that will satisfy Standard S-2043. This is a technical paper that does not take into account the contractual limitations under the Standard Contract for Disposal of Spent Nuclear Fuel and/or High-Level Radioactive Waste (Standard Contract) (10 CFR Part 961). Under the provisions of the Standard Contract, DOE does not consider spent nuclear fuel in multi-assembly canisters to be an acceptable waste form, absent a mutually agreed to contract amendment. To the extent discussions or recommendations in this paper conflict with the provisions of the Standard Contract, the Standard Contract provisions prevail. (authors)

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DOE OSTI2020

Spent Nuclear Fuel Storage and Radioactive Waste Disposal in the United States: A Law and Policy Analysis - 20302

While Congress plays political football, spent nuclear fuel continues to sit in de facto interim nuclear waste storage sites throughout the country. This ad hoc approach - if it can even be called an approach - to nuclear waste management is in no one's best interests, because of financial, safety, environmental, and national security concerns with the status quo. Senate leadership had asserted that an up-or-down vote on the Yucca Mountain Project would take place in September or October 2019, but that did not occur. Rather, a conference bill was agreed to, and it provided that, although the nuclear program should receive some funding, funding was not made available for centralized interim storage ('CIS') or the Yucca Mountain Project. The President's FY2021 Budget Request does not contain any proposed funding for the Yucca Mountain Project ('the Project'). This paper will discuss the implications of that process, both for the Project itself and for the U.S. nuclear waste program more generally. In order to provide context for the current situation, this paper will begin by chronicling the history of U.S. nuclear waste management, from the passage of the Nuclear Waste Policy Act of 1982 and to the present day. It will discuss the roles of the U.S. Department of Energy, the Nuclear Regulatory Commission, federal and state political delegations, and the nuclear energy industry. The paper will then identify key themes that can be expected to affect the future of nuclear waste management in the United States. For example, it will consider whether development of additional CIS facilities is a viable short- to medium-term solution. CIS facilities may relieve immediate pressure at decommissioned or soon-to-be-decommissioned nuclear power plants; but with that pressure partially alleviated, support for building a long-term repository may be reduced. It will also discuss opposition by the State of New Mexico and others to the proposed New Mexico CIS project, based not only on siting concerns but also whether it might become a de facto repository, and whether the State of Texas and others may also be opposed, for similar reasons, to the proposed CIS facility in Texas. Additionally, the paper will examine consent-based siting and its implications for Nevada and other states that are potential hosts for spent nuclear fuel storage and disposal facilities. Further, if the Project is not a politically viable solution, the paper will examine whether it is now time for serious consideration of an alternate location for a permanent repository, as well as consideration of other options entirely, such as deep geologic disposal. The paper will conclude by looking ahead to the 2020 elections. It will describe the positions of candidates (particularly Presidential candidates) on spent nuclear fuel storage and disposal options, without advocating for any particular candidate or political party. Perhaps in 2020, we will at least see a start to a solution to the seemingly intractable problem of nuclear waste management in the United States. (authors)

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DOE OSTI2015

SFDS: The criticality assembly for the experimental research of the nuclear spent fuel dissolver in CIAE - 14401

SFDS is the criticality assembly for the experimental research of the spent fuel dissolver in China Institute of Atomic Energy. The spent fuel dissolver, as the bottleneck of spent fuel reprocessing, has so many characteristics such as the dynamic changes, heterogeneous distribution, complex compositions that it is hard to analysis by theoretical method. Without enough experiments, clear bias and uncertainty of the analysis tools the handling limits for criticality safety in dissolver can't be determined. The SFDS, physical designed by MONK 9A code, uses two kinds of nuclear fuels, 3% enrichment solid UO{sub 2} rods and 5.5% enrichment UO{sub 2}(NO{sub 3}){sub 2} solution, will meet the demand of the critical experiments about the dissolvers. Seven series of critical experiments will be present on it, those are on pitches of rods, uranium concentrations of solutions, nitric acid concentrations of solutions, fission products, void fractions, temperatures and dissolve phases. More kinds of experiments could be introduced with the flexible structures of SFDS in the future. The current work on it are testing and debugging with full systems by water and it will be first critical later in 2015. It will become the first benchmark assembly for critical experiments research in the nuclear fuel cycle system in China. (authors)

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DOE OSTI2015

PWR commercial reactor criticals as validation for spent fuel transport cask burnup credit - 14489

The burnup credit approach for a spent fuel transportation cask (SFTC) with a high density basket for 32 PWR fuel assemblies required credit not only for actinides but also for fission products, otherwise the required minimum burnups of fuel assemblies would have been too high to be practical. At the time of the development of the burnup credit methodology for this condition, no established approach existed to quantitatively validate credit for fission products. A validation approach was therefore developed specifically for this application, based on Commercial Reactor Criticals (CRCs). In this approach, hot critical state points of PWR plants were evaluated using the same codes that were used for the burnup credit evaluations for the transportation cask, namely CASMO-4 and MCNP4. A total of 36 of those state-points were analyzed, from 5 plants with two different assembly types. For each axial section of each fuel assembly, a separate CASMO-4 depletion analysis was performed, which required a total of about 4000 individual CASMO runs. The spent fuel compositions were then extracted from the CASMO runs and transferred to MCNP, where each core was modeled, considering the existing 1/8 symmetry. The core operating conditions were taken from work previously performed and documented for the Yucca Mountain project. The results of the MCNP calculations were then analyzed to establish bias and bias uncertainty values. Additional studies were performed to compare the in-core condition for the fuel with the condition that exists for the fuel in the spent fuel transport cask. The paper presents and discusses the results of the calculations, and the analysis of those results to establish bias and bias uncertainty values. The paper also presents results of the studies comparing in-core with transport cask conditions, and discusses the resulting limitations of this approach. (author)

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DOE OSTI2024

Concept of Operations for Advanced Reactor Spent Nuclear Fuel Management

This presentation presents a preliminary description of a concept of operations to incorporate advanced-reactor spent nuclear fuel (SNF) into an integrated waste-management system (IWMS). The evaluation includes SNF from four advanced-reactor concepts with the following fuel types: (1) small modular reactors using oxide fuels, (2) tristructural-isotropic (TRISO) fuels, (3) metallic fuels, and (4) fuel salts. To provide context for the proposed concept of operations for advanced reactors, a comparison is made with traditional light-water reactors (LWRs) to identify potential gaps in the IWMS. The technical differences between advanced reactors and LWRs are assessed to determine the feasibility of managing advanced-reactor waste streams using existing operations and technology. This presentation emphasizes fuel types from Advanced Reactor Demonstration Program reactors: Xe 100, which uses TRISO fuel and Natrium, with its metallic fuels while also analyzing management options for molten-salt reactors and advanced light-water reactors (ALWRs). Understanding the storage, transportation, and disposal requirements of SNF is dependent on both the quantity and characteristics of the SNF generated by nuclear reactors. This presentation provides a high level overview, comparing the anticipated concept of operations for different SNFs from advanced reactors. The IWMS includes at-reactor storage, transportation, potential off-site storage, potential treatment, and disposition. To assess the potential effect of advanced-reactor concept of operations on the IWMS, estimates were made for fuel characteristics that contribute to storage, transportation, disposal, and possible treatment of advanced-reactor SNF. These include canister heat load, dose rates, and criticality-control limits, which are important for determining the condition and configuration of the advanced reactor SNF. At-reactor storage of LWR SNF traditionally involves a spent-fuel pool (SFP) before transfer to an independent spent-fuel storage installation. However, some advanced-reactor concepts, particularly those using TRISO and salt fuels, do not anticipate the use of an SFP. This difference in at-reactor storage could impact the IWMS. Additionally, transportation of advanced-reactor SNF may include additional processes tied to potential off gassing, and transportation of microreactor SNF may occur within the reactor vessel. Some advanced-reactor SNF could also undergo treatment to meet requirements of an acceptable waste form for disposition, and the treatment location will be a major contributor to efficiently performing IWMS responsibilities. Moreover, the quantity of SNF generated is an important consideration for IWMS because it could affect the size of the transportation fleet and potential off-site storage requirements. Additionally, volume and heat load are the primary drivers for SNF disposition. This presentation compares potential packaging options for advanced reactor SNF with traditional LWR packaging to provide a high-level comparison for the needs of the IWMS for advanced-reactor SNF.

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DOE OSTI2026

Modeling Radiolysis and Chemical Reactions during Dry Storage of Aluminum-clad Spent Nuclear Fuel

After aluminum-clad spent nuclear fuel (ASNF) is removed from the reactor, it is initially stored in spent fuel pools, which are specially designed water-filled basins that provide temporary cooling to reduce the temperature of the fuel assemblies and provide radiation shielding. ASNF continues to generate heat due to the radioactive decay of elements within the fuel, which persists for many years post-shutdown as the residual radioactive products decay into more stable elements. During the wet storage period, an oxyhydroxide layer composed of boehmite/bayerite forms on the surfaces of the aluminum cladding from exposure to water in the pools. Road-ready packaging for long-term disposition of the ASNF involves dry storage in helium backfilled DOE standard canisters (DSCs). When the ASNF is removed from water storage and dried, most of the water is removed, but some physisorbed and chemisorbed water remains in the oxyhydroxide layers. This residual water can produce hydrogen when exposed to radiation from the ASNF during dry storage. Predicting hydrogen accumulation over time in the DSCs is critical for long-term storage considerations. Previous modeling efforts have developed coupled computational fluid dynamics (CFD)-chemical models to simulate temperature, pressure, and gas phase concentrations within the DSCs. These models use the thermal field predicted by CFD as input to a radiolysis model for the gas phase and the surface oxyhydroxide layer chemistry. Given the long storage period of the DSCs and the impracticality of long-term experiments, a simulation-based approach is necessary to assess chemical evolution within the canisters. This study advances the development of a modeling framework designed to simulate the chemical evolution of spent fuel canisters. Both thermal and radiation-driven reactions are considered, with radiation kinetics quantified using G-values. Sensitivity analysis identifies key parameters influencing species composition. Reaction pathway diagrams offer insight into dominant species formation routes, enabling more effective comparisons between model predictions and experimental observations, particularly regarding the production of hydrogen. Results show that the model predicts significant hydrogen gas production with minimal oxygen generation, primarily due to hydrogen formation via boehmite pathways. These findings underscore the importance of accurately characterizing surface-bound species and radiolysis kinetics. A deeper understanding of these mechanisms is critical for evaluating the long-term safety of nuclear waste storage.

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DOE OSTI2021

Preliminary Modeling of Chloride Deposition on Spent Nuclear Fuel Canisters in Dry Storage Relevant to Stress Corrosion Cracking

This study presents a method that can be used to gain information relevant to determining the corrosion risk for spent nuclear fuel (SNF) canisters during extended dry storage. Currently, it is known that stainless steel canisters are susceptible to chloride-induced stress corrosion cracking (CISCC). However, the rate of CISCC degradation and the likelihood that it could lead to a through-wall crack is unknown. This study uses well-developed computational fluid dynamics and particle-tracking tools and applies them to SNF storage to determine the rate of deposition on canisters. The deposition rate is determined for a vertical canister system and a horizontal canister system, at various decay heat rates with a uniform particle size distribution, ranging from 0.25 to 25 µm, used as an input. In all cases, most of the dust entering the overpack passed through without depositing. Most of what was retained in the overpack was deposited on overpack surfaces (e.g., inlet and outlet vents); only a small fraction was deposited on the canister itself. These results are provided for generalized canister systems with a generalized input; as such, this paper is intended to demonstrate the technique. This study is a part of an ongoing effort funded by the U.S. Department of Energy, Nuclear Energy Office of Spent Fuel Waste Science and Technology, which is tasked with doing research relevant to developing a sound technical basis for ensuring the safe extended storage and subsequent transport of SNF. This work is being presented to demonstrate a potentially useful technique for SNF canister vendors, utilities, regulators, and stakeholders to utilize and further develop for their own designs and site-specific studies.

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DOE OSTI2015

Laying the groundwork for a large-scale spent nuclear fuel transportation system - 15408

The US Department of Energy Office of Nuclear Energy established the Nuclear Fuels Storage and Transportation Planning Project to lay the groundwork for implementing an interim storage facility, including associated transportation activities. Efforts include the development of a system for the large-scale transport of spent nuclear fuel that will be necessary in an integrated waste management system. Progress is being made on long lead time, destination-independent aspects of the transportation infrastructure. The large-scale transportation system for spent nuclear fuel is divided into three elements: institutional, operational, and hardware. The institutional element refers to the various forms of stakeholder interaction that must occur for this type of transportation system to be successful. It includes activities like development of a national transportation plan, work on policy development for Section 180(c) of the Nuclear Waste Policy Act, and identification of a preliminary suite of national transportation routes that reflect the interests of a broad cross section of stakeholders while meeting regulatory requirements. The operational element refers to the activities that must be undertaken to run a large-scale transportation system. This element is currently focused on development of a new SNF transportation routing analysis tool, study of the infrastructure near SNF storage sites that may be de-inventoried first, and development of tools for modeling transportation activities. The hardware element refers to the casks, railcars, and other items necessary to operate the system. This element currently focuses on development of railcars compliant with Association of American Railroads Standard S-2043, as well as studies related to the use of rail casks and their ancillary equipment. The Nuclear Fuels Storage and Transportation Planning Project is making significant progress in all three of these areas along the path forward to a fully operational transportation system. (authors)

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