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Used fuel disposition research and development roadmap - FY10 status.

Since 1987 the U.S. has focused research and development activities relevant to the disposal of commercial used nuclear fuel and U.S. Department of Energy (DOE) owned spent nuclear fuel and high level waste on the proposed repository at Yucca Mountain, Nevada. At the same time, the U.S. successfully deployed a deep geologic disposal facility for defense-related transuranic waste in bedded salt at the Waste Isolation Pilot Plant. In 2009 the DOE established the Used Fuel Disposition Campaign (UFDC) within the Office of Nuclear Energy. The Mission of the UFDC is to identify alternatives and conduct scientific research and technology development to enable storage, transportation and disposal of used nuclear fuel and wastes generated by existing and future nuclear fuel cycles. The U.S. national laboratories have participated on these programs and has conducted research and development related to these issues to a limited extent. However, a comprehensive research and development (R&D) program investigating a variety of geologic media has not been a part of the U.S. waste management program since the mid 1980s. Such a comprehensive R&D program is being developed in the UFDC with a goal of meeting the UFDC Grand Challenge to provide a sound technical basis for absolute confidence in the safety and security of long-term storage, transportation, and disposal of used nuclear fuel and wastes from the nuclear energy enterprise. The DOE has decided to no longer pursue the development of a repository at Yucca Mountain, Nevada. Since a repository site will ultimately have to be selected, sited, characterized, designed, and licensed, other disposal options must now be considered. In addition to the unsaturated volcanic tuff evaluated at Yucca Mountain, several different geologic media are under investigation internationally and preliminary assessments indicate that disposal of used nuclear fuel and high level waste in these media is feasible. Considerable progress has been made in the U.S. and other nations in understanding disposal concepts in different geologic media, but gaps in knowledge still exist. A principal aspect of concern to the UFDC as it considers the broad issues of siting a repository in different geologic media are the marked differences in the regulatory bases for assessing suitability and safety of a repository between the U.S. and other nations. Because the probability based - risked informed nature of the current U.S. regulations for high-level radioactive waste and spent nuclear fuel is sufficiently different from other regulations, information gained in previous studies, while useful, likely need to be supplemented to enable more convincing communication with the public, better defense of the numerical models, and stronger safety cases. Thus, it was recognized when the UFDC was established that there were readily identified disposal-related R&D opportunities to address knowledge gaps. An effort to document these research opportunities was a key component of Fiscal Year (FY) 2010 engineered system, natural system, and system-level modeling activities for a range of disposal environments. A principal contribution to identifying these gaps was a workshop held to gather perspectives from experts both within and external to the UFDC regarding R&D opportunities. In the planning for FY2010 it was expected that these activities would culminate with a UFDC research and development roadmap that would identify the knowledge gaps, discuss the R&D needed to fill these gaps, and prioritize the proposed R&D over both the near- and long-term. A number of knowledge gaps and needed R&D were identified and are discussed in this report. However, these preliminary R&D topics have not been evaluated in detail nor have they been prioritized to support future planning efforts. This will be completed in FY11 and the final UFDC Research and Development Roadmap will be completed. This report discusses proposed R&D topics in three areas related to repository siting, design, and performance: natural systems, engineered systems, and overall disposal system. The intent of this report is to consolidate the proposed R&D topics to support subsequent discussions among UFDC and external expertise to identify additional R&D needs and to prioritize these needs, leading to the development for the UFDC Research and Development Roadmap.

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Backend Nuclear Fuel Cycle Radiation Chemistry

Given global commitments to significantly increase nuclear energy capacity, it is now more important than ever to develop efficient used nuclear fuel management strategies to improve resource utilization, energy security, and waste minimization. Here, an overview of nuclear energy, backend fuel cycle challenges, and advances in used nuclear fuel reprocessing radiation chemistry will be presented. More specifically, the use of electron pulse irradiation techniques to explore radiation-induced reaction mechanisms in actinide containing solutions and solvent systems.

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Principles and Tasks of the New Regulatory System for Radioactive Waste Management in the Russian Federation - 12020

This year the Federal Law 'On Radioactive Waste management' was adopted in the Russian Federation. The law significantly changes the existing radioactive waste management regulatory system and assigns a lot of new tasks in order to implement new principles and overcome inevitable respective difficulties. Nuclear Safety Institute was largely involved in the process of the development of the law as well as its further co-ordination among the stakeholders, during which some important initial provisions were excluded. In the paper special features of the Russian safety regulation system for radioactive waste management are analyzed. Most significant requirements adopted by the law as well as tasks and expected difficulties related to its implementation are discussed. (authors)

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REAL TIME DATA FOR REMEDIATION ACTIVITIES [11505]

Health physicists from the CH2M HILL Plateau Remediation Company collaborated with Berkeley Nucleonics Corporation to modify the SAM 940 isotope identifier instrument to be used for nuclear waste remediation. These modifications coupled with existing capabilities of the SAM 940 have proven to be invaluable during remediation activities, reducing disposal costs by allowing swift remediation of targeted areas that have been identified as having isotopes of concern (IOC), and eliminating multiple visits to sites by declaring an excavation site clear of IOCs before demobilizing from the site. These advantages are enabled by accumulating spectral data for specific isotopes that is nearly 100 percent free of false positives, which are filtered out in 'real time.'

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Hyperspectral Raman imaging using a spatial heterodyne spectrometer (SHS)

Savannah River National Laboratory, and the larger community, has limited chemical-specific imaging capabilities, which would be beneficial for remote detection of threat chemicals or use in inaccessible and harsh environments, as well as in-line process monitoring. Chemical imaging technology would support multiple directorates through stand-off detection of chemicals (National Security), and imaging of chemical distributions in a process (Nuclear Materials Management, Clean Energy) and in waste tanks (Environmental Stewardship). Chemical-specific imaging is underdeveloped due to issues of sensitivity, stable alignment and calibration, and ease of operation associated with most optical instruments. The project objective is to develop a novel, rugged, highly sensitive spectrometer to support real-time, chemically specific imaging using hyperspectral Raman spectroscopy. Raman spectroscopic analysis will provide chemical specificity and using a spatial heterodyne spectrometer (SHS) will increase the sensitivity due to the high light throughput design. The SHS design does not require moving parts allowing for a very stable system, reducing alignment and calibration issues. The instrument will be assembled and initially applied to Raman gas detection of the Saltstone disposal unit headspace gas concentrations. Raman gas analysis is the most impacted by sensitivity issues and will be used to demonstrate the increased light collection capability of the SHS over a conventional dispersive spectrometer. The system will be later modified to image spectral information in a spatial domain to provide information on the spatial distribution of a sample scene.

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Management of Radioactive Wastes (RWs) and Disused Sealed Radioactive Sources (DSRSs) in Bangladesh: Recent Activities and Challenges Ahead - 16039

The use of radioactive sources in different applications and practices gives rise to various types of RWs that may be detrimental to human health and the environment if not properly managed. Since early sixties of the last century, radioisotopes have found diversified and incremental uses in Bangladesh in the field of medicine, industry, agriculture, food irradiation, research and education and so on. Currently, the country is operating nuclear facilities like 3 MW TRIGA research reactor (TRR), radioisotope production (RIP) facility as well as particle accelerators. Recently, the country has decided to establish nuclear power plants in order to cope with its increasing demand of electric power. The first nuclear power plant is anticipated to come into operation by 2021-2022. Consequently, a notable amount and range of RWs including DSRSs are being expected to be generated from these diversified applications of radioactive materials in near future. Bangladesh has limited facilities and capabilities to manage the RWs which are being currently generated from the conventional activities and practices with radioactive materials. However, the country is also working to improve its necessary capabilities and infrastructures for the management of RWs expected to be generated from both conventional and nuclear activities in future in a comprehensive, integrated and safer manner, ensuring that no undue burden is imposed on present and future generations and on the environment. This paper illustrates the current activities as well as its future plans on the management of RWs and DSRSs in the country. (authors)

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Preliminary Evaluation of Removing Used Nuclear Fuel from Shutdown Sites

This report fulfills the M2 milestone M2FT-13PN0912022, “Stranded Sites De-Inventorying Report.” In January 2013, the U.S. Department of Energy (DOE) issued the Strategy for the Management and Disposal of Used Nuclear Fuel and High-Level Radioactive Waste (DOE 2013). Among the elements contained in this strategy is an initial focus on accepting used nuclear fuel from shutdown reactor sites. This focus is consistent with the recommendations of the Blue Ribbon Commission on America’s Nuclear Future, which identified removal of stranded used nuclear fuel at shutdown sites as a priority so that these sites may be completely decommissioned and put to other beneficial uses (BRC 2012). Shutdown sites are defined as those commercial nuclear power reactor sites where the nuclear power reactors have been shut down and the site has been decommissioned or is undergoing decommissioning. In this report, a preliminary evaluation of removing used nuclear fuel from 12 shutdown sites was conducted. The shutdown sites were Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, Zion, Crystal River, Kewaunee, and San Onofre. These sites have no other operating nuclear power reactors at their sites and have also notified the U.S. Nuclear Regulatory Commission that their reactors have permanently ceased power operations and that nuclear fuel has been permanently removed from their reactor vessels. Shutdown reactors at sites having other operating reactors are not included in this evaluation.

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Crickets{sup TM} and Curies: Lessons Learned from the Steel Industry - 18221

The global nuclear power industry, and to a lesser extent, the decommissioning and demolition of old nuclear weapons plants, obviously present challenges to those in the radioactive waste management field. Some if not many of these challenges have already been dealt with, and resolved, in the steel industry, including its recycling component. This paper presents proven state-of-the-art radiation detection systems used in steel and related recycling facilities, emphasizing current, reliable and flexible technologies for characterization, volume reduction, and remote handling of recyclable solid wastes contaminated and, just as important, not contaminated, with a wide range of radioactive isotopes. It will also cover features of remotely operated waste handling equipment effective in reducing or eliminating exposure of workers engaged in decontamination and demolition work on active and/or inactive nuclear installations. The industry group identified above has a long-standing policy regarding any radioactivity in potentially recyclable as well as waste materials it receives: if it is detected, it is rejected. The US Steel Manufacturers Association (SMA) put it this way in one of their Public Policy Statements: 'SMA members have not, and will not, accept scrap that is known to be radioactively contaminated' (emphasis included in the original) (1). This policy, adopted around the globe, obviously has major implications for decommissioning and demolition projects. To put it bluntly, if rad-contaminated metal, concrete, or other materials are sent to a facility for possible recycling, reuse or even disposal, they may well be rejected. If so, the materials will be returned to the generator--at the generator's cost-and a new solution will have to be found. This also results in additional costs for the generator. Facilities in the steel making and metal recycling industries have access to, and routinely count on, a wide range of proven detection technologies and techniques for monitoring incoming shipments and sorting the materials in them. The approaches range from using sensitive handheld instruments for pinpointing and isolating small devices such as isotope-containing gauges and radium dials all the way up to technologies effective for large volumes and weights of contaminated construction and demolition material. In this latter realm, the most suitable, robust, and field-proven system for decommissioning and demolition work is a radiation detection system fitted to a grappling and/or magnetic device, known as the Crickets{sup TM} technology, which automatically scans bulk material with no added effort or time in material handling operations. Highly versatile, a Crickets{sup TM} system can be put to work on any material-handling system, including grapples handling volumes ranging from 1 up to 18 cubic yards, while detecting radioactivity in real-time over a very wide dose range, from nSv to Sv levels. Other field-proven real-time measuring radiation detection devices can be fixed to conveyor belts with traverse speeds up 3 meters/second, also measuring in real time and over the same dose range, allowing both recyclable and waste materials with a pre-set level of radioactivity to be diverted off the belt. Finally, there are highly sensitive radiation portal installations for detecting radiation from materials being transported by vehicles, including those with roll-offs, dump trailers, and other containers, again in real-time and for the same dose ranges. For vehicles, the speed must be carefully controlled-the vehicles need to travel from 5 to 10 km/h through the scanning zone to ensure that maximum detection capability is maintained. When radiation detection systems at recycling and steel making facilities detect radioactive material in an incoming shipment, these facilities have a zero tolerance for accepting the cargo. Therefore, it is imperative that material from a demolition operation that is slated to be sent for recycling or other reuse be checked at the point of demolition at similar detection levels to avoid possible rejection later of a shipment because of its radioactivity. In addition to measuring overall radiation levels (for example, total gamma), when necessary, combinations of different radiation detection media can be used to detect the presence and intensities of specific isotopes such as U-235, Cs-137, Co-60, Am-241, etc., again in real-time and over a similar dose range. These detection technologies can be fixed or transportable. More important for the rad-waste management profession, this overall systems approach can be tailored and adapted during use on-site in any dismantling, demolition or remediation project, to allow materials to be thoroughly scanned before being released to the recycling stream for reuse, or to appropriate long-term storage and disposal facilities. Potentially recyclable materials with contamination such as steel beams and rebar will set off alarms at recycling facilities, resulting in unnecessary added expenses to the generator, primarily due to increased transportation costs, time delays and additional rad-waste handling and disposal charges. Additionally, there are situations where relatively lightly contaminated materials, once identified and appropriately characterized, can be reused in new construction applications, such as concrete from demolition being used in the base layer for roads or recycled steel used for repair or construction of bridges. In other cases, specific smaller volumes can be sent to specialized rad-waste disposal sites. These radiation detection systems can also be custom tailored to ensure proper handling and disposition of contaminated materials destined for reuse in specific applications where, for example, acceptable levels of radioactivity in NORM or TENORM can be reused or safely disposed of. (authors)

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Vitrification of IFR and MSBR halide salt reprocessing wastes

Both of the genuinely sustainable (breeder) nuclear fuel cycles (IFR - Integral Fast Reactor - and MSBR - Molten Salt Breeder Reactor -) studied by the USA's national laboratories would generate high level reprocessing waste (HLRW) streams consisting of a relatively small amount ( about 4 mole %) of fission product halide (chloride or fluoride) salts in a matrix comprised primarily (about 95 mole %) of non radioactive alkali metal halide salts. Because leach resistant glasses cannot accommodate much of any of the halides, most of the treatment scenarios previously envisioned for such HLRW have assumed a monolithic waste form comprised of a synthetic analog of an insoluble crystalline halide mineral. In practice, this translates to making a 'substituted' sodalite ('Ceramic Waste Form') of the IFR's chloride salt-based wastes and fluoroapatite of the MSBR's fluoride salt-based wastes. This paper discusses my experimental studies of an alternative waste management scenario for both fuel cycles that would separate/recycle the waste's halide and immobilize everything else in iron phosphate (Fe-P) glass. It will describe both how the work was done and what its results indicate about how a treatment process for both of those wastes should be implemented (fluoride and chloride behave differently). In either case, this scenario's primary advantages include much higher waste loadings, much lower overall cost, and the generation of a product (glass) that is more consistent with current waste management practices. (author)

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Retrieval of Transuranic Drums with Deflagration to Detonation Potential from a Vault at the Oak Ridge National Laboratory - 20207

During the final phase of a long-term project, a total of 80 TRU waste drums at ORNL have been retrieved from a below-grade storage vault in which they have remained untouched for about 25 years. The drums, which house material generated from past ORNL operations, are now stored and ready for eventual transfer to the Transuranic Waste Processing Center, located on Highway 95 in Oak Ridge. The Transuranic Waste Processing Center will process and ship the drums to WIPP in Carlsbad, New Mexico, for disposal. Workers lifted the drums one-by-one from the underground storage vault with a 110-ton crane over a one-week period in October 2017. Although the physical work was performed in one week, years of detailed planning preceded the fieldwork. A key obstacle needed to be overcome before the project could safely proceed. This obstacle involved the need to ensure controls were developed for the Deflagration to Detonation Transition (DDT) potential. DDT refers to a phenomenon in ignitable mixtures of a flammable gas and air (or oxygen) when a sudden transition takes place from a deflagration type of combustion to a detonation type of explosion. Basically, these drums, under certain circumstances, have a potential to detonate and overpressurize. Extensive analysis of the drums verified that detonation, while unlikely, was possible. Of the total 103 drums that were retrieved or moved in preparation for retrieval, 18 had DDT potential. Extensive security requirements were also necessary, due to the nature of the material, and this added another layer of complexity to the fieldwork. Prior to retrieving the drums from the underground storage vault, space needed to be made for them within the various above-grade facilities. Inventory and security requirements dictated what could be stored where, and the first step of the field work involved a number of drum movements in preparation for storage of the newly retrieved drums. This effort involved moving 21 drums already in the storage area to facilitate the addition of the newly retrieved ones. The retrieval project required a total of 107 critical lifts using the 110-ton crane, under 3 critical lift plans. The TRU waste storage facility is a Category 2 Nuclear Facility and is managed under an extensive Documented Safety Analysis. The TRU retrieval project was conducted in accordance with DOE Order 425.1D and included three Implementation Verification Reviews, two Management Assessments, one Readiness Assessment, and seven mock-ups in preparation for the field work. Despite being stored for 25 years, the drums were in good shape due to the integrity of the facilities where the drums were stored. Of the 80 drums that were retrieved, 12 were placed in special containers called 'overpacks' based on their content. The drums were removed safely and without incident, thanks to a lot of preparation and the efforts of a highly skilled team. Lessons learned through the DDT control development and the drum retrieval and overpacking process could be beneficial to others having to manage similar drums of TRU waste. (authors)

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International Standards Development and Its Role in Transitioning D and D Technologies to Deployment - 18315

As the need to perform deactivation and decommissioning (D and D) of the most challenging nuclear facilities worldwide is growing, facilitating the integration of state-of-the-art, cutting edge technologies will be critically important to safely, effectively, and efficiently complete this mission. However, end users in the field face significant obstacles to integrating new technologies into cleanup initiatives. By leveraging the development of international standards and testing protocols, the risks associated with implementing new technologies can be mitigated and further support the need to update existing directives and guidance handbooks to account for the tremendous recent advancements in technology development. The American Society for Testing and Materials (ASTM) International's E10.03 Subcommittee on Radiological Protection for D and D of Nuclear Facilities and Components has begun the development of standard specifications and uniform testing protocols designed to support the nuclear industry's testing and evaluation requirements for D and D technologies. The vision of the E10.03 Subcommittee is to promulgate operationally relevant, uniform testing protocols that can be leveraged by the various technology innovation and development programs across the nuclear environmental management community, and support decision makers and end users with common references in the selection and employment of those standards and associated technologies. These standards could also serve as the basis for updating existing directives and guidance documents such as the various DOE handbooks to better account for the role of cutting edge technology, and facilitate / expedite lab to market efforts that result in improved returns on investment (ROIs) for technology development programs. (authors)

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Effects of anisotropic shale creep on the stress and permeability evolution of a geological nuclear waste repository

To ensure long-term safety and performance, geological nuclear waste repositories require low-permeability barriers such as bentonite buffers and/or shale host rock. Shale is not only known for its low permeability but also for its trend to undergo time-dependent deformation (i.e., creep), which could heal damage, but the effects of shale creep on the long-term performance of nuclear waste repositories have not been clearly understood. In particular, the anisotropic nature of shale (i.e., bedding) could have a significant effect on its creep behavior, and consequently, on the long-term performance of nuclear waste repositories. In this research, numerical simulations were carried out with the objective of showing the effects of anisotropic shale creep on the stress and permeability evolution of a generic geological nuclear waste repository in shale. The TOUGH-FLAC simulator, a thermo-hydromechanically (THM) coupled numerical code, was used for the simulations. To achieve the objective, comparisons were performed between the results of anisotropic shale creep simulations and those of different simulation cases, namely, no creep (i.e., elastic), isotropic creep, and long-term creep shale cases. Results of the comparisons show that the elastic and isotropic creep shale cases respectively led to the overestimation and underestimation of stress and permeability in the repository, whereas the long-term creep shale case, which accumulated greater creep in later periods than in earlier periods, helped to keep large shear and tensile stresses from developing while maintaining compressive spherical stress, resulting in consistently low permeability levels. These results indicate that performance assessments with elastic and isotropic creep formation models will provide the upper and lower bound estimates of stress and permeability, while more reasonable estimates will be given by an anisotropic creep formation model, and that shale with long-term creep characteristics will be beneficial in many aspects of the safety and performance of nuclear waste repositories.

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Design innovation for the management of alpha contaminated unserviceable glove boxes

With the maturing of nuclear industry, there is an added burden on the Back End of fuel cycle. Radioactive facilities are in the need for refurbishment. This paper describes the steps adopted for managing such alpha contaminated unserviceable Glove Boxes. The first step consisted of in-situ encasement of individual Glove Boxes, encountering the challenges of low head room and space congestion in these laboratories with cognizance to regulatory requirement related to radiation safety. The second step was removal, transfer and placement of encased Glove Boxes in a dedicated facility under continuous surveillance. The glove boxes will remain stored in this facility until arrangements are completed for dismantling and volume reduction in another facility dedicated for this purpose. The final step is the development of an appropriate technique for dismantling/cutting of Glove Boxes in an alpha-tight facility constructed to prevent spread of airborne activity, collection of cut pieces, subsequent decontamination of these metallic wastes and disposal. The paper describes the design scheme for dismantling of the glove box. The description also includes hands on evaluation of tools and gadgets in pilot set-up with a view to incorporating the most credible choice in an upcoming active facility. (authors)

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