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Deep Geologic Nuclear Waste Disposal - No New Taxes - 12469

To some, the perceived inability of the United States to dispose of high-level nuclear waste justifies a moratorium on expansion of nuclear power in this country. Instead, it is more an example of how science yields to social pressure, even on a subject as technical as nuclear waste. Most of the problems, however, stem from confusion on the part of the public and their elected officials, not from a lack of scientific knowledge. We know where to put nuclear waste, how to put it there, how much it will cost, and how well it will work. And it's all about the geology. The President's Blue Ribbon Commission on America's Nuclear Future has drafted a number of recommendations addressing nuclear energy and waste issues (BRC 2011) and three recommendations, in particular, have set the stage for a new strategy to dispose of high-level nuclear waste and to manage spent nuclear fuel in the United States: 1) interim storage for spent nuclear fuel, 2) resumption of the site selection process for a second repository, and 3) a quasi-government entity to execute the program and take control of the Nuclear Waste Fund in order to do so. The first two recommendations allow removal and storage of spent fuel from reactor sites to be used in the future, and allows permanent disposal of actual waste, while the third controls cost and administration. The Nuclear Waste Policy Act of 1982 (NPWA 1982) provides the second repository different waste criteria, retrievability, and schedule, so massive salt returns as the candidate formation of choice. The cost (in 2007 dollars) of disposing of 83,000 metric tons of heavy metal (MTHM) high-level waste (HLW) is about $ 83 billion (b) in volcanic tuff, $ 29 b in massive salt, and $ 77 b in crystalline rock. Only in salt is the annual revenue stream from the Nuclear Waste Fund more than sufficient to accomplish this program without additional taxes or rate hikes. The cost is determined primarily by the suitability of the geologic formation, i.e., how well it performs on its own for millions of years with little engineering assistance from humans. It is critical that the states most affected by this issue (WA, SC, ID, TN, NM and perhaps others) develop an independent multi-state agreement in order for a successful program to move forward. Federal approval would follow. Unknown to most, the United States has a successful operating deep permanent geologic nuclear repository for high and low activity waste, called the Waste Isolation Pilot Plant (WIPP) near Carlsbad, New Mexico. Its success results from several factors, including an optimal geologic and physio-graphic setting, a strong scientific basis, early regional community support, frequent interactions among stakeholders at all stages of the process, long-term commitment from the upper management of the U.S. Department of Energy (DOE) over several administrations, strong New Mexico State involvement and oversight, and constant environmental monitoring from before nuclear waste was first emplaced in the WIPP underground (in 1999) to the present. WIPP is located in the massive bedded salts of the Salado Formation, whose geological, physical, chemical, redox, thermal, and creep-closure properties make it an ideal formation for long-term disposal, long-term in this case being greater than 200 million years. These properties also mean minimal engineering requirements as the rock does most of the work of isolating the waste. WIPP has been operating for twelve years, and as of this writing, has disposed of over 80,000 m{sup 3} of nuclear weapons waste, called transuranic or TRU waste (>100 nCurie/g but <23 Curie/1000 cm{sup 3}) including some high activity waste from reprocessing of spent fuel from old weapons reactors. All nuclear waste of any type from any source can be disposed in this formation better, safer and cheaper than in any other geologic formation. At the same time, it is critical that we complete the Yucca Mountain license application review so as not to undermine the credibility of the Nuclear Regulatory Commission and the scientific community. (authors)

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A Dynamic Waste Isolation Pilot Plant Performance Assessment Tool - 12490

The Waste Isolation Pilot Plant (WIPP) Performance Assessment (PA) methodology comprises a toolbox used to demonstrate regulatory compliance of the repository after facility closure. The PA framework rests upon an extensive suite of computational codes. In some cases, significant alteration of code inputs is a tedious and difficult task. Due to the nature of the application for which they are used, PA codes used in support of WIPP regulatory compliance demonstration must satisfy stringent quality assurance requirements. Consequently, many of the coding practices used during original code development are still implemented today. A more efficient workflow configuration has the potential to alleviate difficulties associated with extensive code input modifications. Here, this potential is assessed via an implementation of a more flexible scientific workflow system for a subset of the codes used in WIPP PA. The scientific workflow approach taken here for a dynamic PA system enables users from disparate backgrounds to dramatically shorten the time between hypothesis and analysis by decreasing the amount of a priori knowledge, from a range of disciplines, needed to execute the code. Having smaller iteration times allows for more ideas to be tested and explored, which leads to safer and more optimized systems. Note that these high-level, dynamic tools are intended only for initial scoping studies on the personal computer of a researcher. Full, regulatory compliance calculations may occur only within a qualified computing environment. However, the WIPP PA tools here may guide future research and indicate regions of the analysis space that are worth further study. This next generation of PA software provides the ability to perform scoping investigations of repository performance quickly and easily, and has an accessible and useful interface to a variety of users, such as fuel cycle systems designers, domain experts such as repository modelers, and policy makers. The purview of this project allows for many opportunities for future work. Foremost among these is the desire to implement the full BRAGFLO suite within the workflow. This will entail porting or wrapping Genmesh, Matset, LHS, and ICSet within Python. Moreover, unifying the two GUIs into a single driver application would be a natural next step. Once the BRAGFLO suite is completed, other portions of WIPP PA could be implemented with corresponding and inter-operable work-flows. Likely first candidates for this are those codes that are similarly computationally intensive, such as the one used to generate complementary cumulative distribution functions used to demonstrate regulatory compliance (code CCDFGF). (authors)

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Operational Challenges of Extended Dry Storage of Spent Nuclear Fuel - 12550

As a result of the termination of the Yucca Mountain used fuel repository program and a continuing climate of uncertainty in the national policy for nuclear fuel disposition, the likelihood has increased that extended storage, defined as more than 60 years, and subsequent transportation of used nuclear fuel after periods of extended storage may become necessary. Whether at the nation's 104 nuclear energy facilities, or at one or more consolidated interim storage facilities, the operational challenges of extended storage and transportation will depend upon the future US policy for Used Fuel Management and the future Regulatory Framework for EST, both of which should be developed with consideration of their operational impacts. Risk insights into the regulatory framework may conclude that dry storage and transportation operations should focus primarily on ensuring canister integrity. Assurance of cladding integrity may not be beneficial from an overall risk perspective. If assurance of canister integrity becomes more important, then mitigation techniques for potential canister degradation mechanisms will be the primary source of operational focus. If cladding integrity remains as an important focus, then operational challenges to assure it would require much more effort. Fundamental shifts in the approach to design a repository and optimize the back-end of the fuel cycle will need to occur in order to address the realities of the changes that have taken place over the last 30 years. Direct disposal of existing dual purpose storage and transportation casks will be essential to optimizing the back end of the fuel cycle. The federal used fuel management should focus on siting and designing a repository that meets this objective along with the development of CIS, and possibly recycling. An integrated approach to developing US policy and the regulatory framework must consider the potential operational challenges that they would create. Therefore, it should be integral to these efforts to redefine retrievability to apply to the dual purpose cask, and not to apply to individual assemblies. (authors)

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The safety improvement of Romanian radioactive waste facilities as an example for human and environmental protection

According to IAEA classification, Romania with two nuclear research centres, with 2 Nuclear Power Units in operation at Cernavoda Town and with 2 new Units envisaged to be in operation soon, can be considered as a country with an average nuclear activity. In Romania there was an extensive interest in management of radioactive wastes generated by the use of nuclear technology in industry and research. Using the most advanced technologies in the mentioned time periods, Romania successfully accomplished to solve all management issues related to radioactive wastes being addressed all safety concerns. Every step of nuclear activity development was accompanied by the suitable waste management facilities. So that, in order to improve the existing treatment and disposal capacities for institutional waste, the existing Radioactive Waste Treatment Facility (STDR) and the National Repository Radioactive Wastes (DNDR) at Baita, Bihor, will be improved to actual requirements on the occasion of VVR-S Research Reactor decommissioning. This activity is in development into the frame of a National funded project related to disposal galleries filling improvement and repository closure for DNDR Baita, Bihor. All improvements will be approved by Environmental Protection Authority and Regulatory Body, being a guaranty of human and environmental protection. Also, in accordance with national specific and international policies and taking into account decommissioning activities related to the present operating NPPs, all necessary measures were considered in order to avoid unnecessary generation of radioactive wastes, to minimize, as much as possible, waste production and accumulation and the necessity to develop optimum solutions for a new repository with the assurance of improved nuclear safety. (authors)

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Swedish Solution for Reconditioning, Transport, Interim Storage and Final Disposal of Failed Fuel - 17024

Despite today's increasingly more reliable operation of nuclear power plants, failed fuel rods exist in all Swedish plants. Managing intermediate storage and sub-sequential final disposal of such rods has been a growing problem. The Swedish system for spent fuel management uses the principle of intermediate storage of the fuel in a central intermediate storage facility (CLAB) before disposal in a final repository according to the KBS-3 method. However, the intermediate storage facility does not allow storage of failed fuel and the final repository has limitations on moisture in the deposited fuel and hence failed or broken fuel rods cannot be accepted as-is. The nuclear power companies in Sweden have jointly established the Swedish Nuclear Fuel and Waste Management Co, SKB, to manage the spent fuel and the operational waste. To find a solution to transport the failed fuel to storage, SKB has established a project with the goal to have all currently failed fuel rods from all the Swedish nuclear power plants reconditioned and transported to the intermediate storage facility before the year of 2020. The project has established the acceptance criteria for reconditioned failed fuel in the final repository and evaluated a number of options for treatment, encapsulation and transportation of the failed fuel rods. Furthermore, two suppliers have developed reconditioning methods fulfilling the criteria and contracts were signed with both suppliers in May 2016. This paper outlines the details of the Swedish solution for treatment and storage of failed fuel including the technical requirements for the reconditioning method and transportability. (authors)

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Legacy Waste Containers for Low and Intermediate Level Radioactive Waste in Germany - Actual Situation and Challenges - 17070

Low and intermediate level radioactive waste has been produced in Germany for several decades. While a part of the waste had been deposited in the Morleben repository and the Asse mine which have been operated for just a limited period of time, the major amount is conditioned and packaged in temporarily stored waste containers. Those containers are designated for final disposal in the KONRAD repository being currently under construction and expected to start operation in 2022. As a consequence, an assessment of the waste container documentation and safety is strongly needed to receive an approval for the Konrad repository. This requalification is challenging because those old containers have to meet the same safety requirements as new containers. (authors)

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Influence of Calcium Concentration on Permeability Changes in Flow-paths Altered by Highly Alkaline Groundwater - 17129

Groundwater around the geological repository of HLW is altered to the highly alkaline and Ca-rich condition by the constituents leaching from cementitious materials. Under such condition, the formation of CSH will affect the migration of radionuclides with the change in the hydraulic and chemical properties of the fracture (micro flow-path) in the host rock. In particular, the clogging effect with the deposition of CSH in the flow path the may contribute the retardation of radionuclide migration. In this study, the influence of Ca concentration on such clogging effect in the micro flow-path under the highly alkaline condition was examined by estimating the permeability changes with the deposition of CSH. In the experiment, the micro fractures in host rock were simulated by the micro flow-cell nipping the Teflon sheet (80 μm of thickness) between a granite chip and Teflon basement. The flow experiment was conducted by continuously injecting Ca solution to the micro flow-cell with constant flow rate. The concentrations of Ca ions for the injection solution were set in the range from 0 to 7.5 mM, and the value of pH was 12.5. As a result, under all conditions of Ca concentrations, the permeability in the flow path decreased to the range of 1. 10{sup -10} to 2.0x10{sup -10} m{sup 2} with the deposition of CSH. Besides, such decreased permeability was almost constant with increasing and decreasing periodically. Such increase and decrease in the permeability will be caused by the deposition and outflow of CSH formed in the flow path. In other words, because CSH is stable in pH higher than at least 10, under the condition with no man-made outlet such as real underground around the repository of radioactive waste, most CSH might clog through the flow-paths in the spatial range where pH exceeds at least 10, contributing the retardation effect of the migration of radionuclides released from the repository. (authors)

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Potential Cost Implications of an Interim Storage Facility for Commercial SNF+ - 17132

The question of whether or not consolidated interim storage of commercial spent nuclear fuel (SNF) should be part of the federal waste management system as an intermediate step before permanent disposal has been debated for more than four decades. This paper summarizes an evaluation of the cost implications of incorporating a consolidated interim storage facility (ISF) into the waste management system (WMS). In this study, the order-of-magnitude estimates of total system costs were calculated and tabulated. The analyzed scenarios involve shipment of SNF from reactors in dual-purpose storage and transportation canisters (DPCs) currently being used by utilities for dry storage at reactor sites. A number of pertinent conclusions can be drawn from this evaluation, including: - Delay in repository availability increases total system costs. Any delay in opening a repository increases total system costs, regardless of whether the system has an ISF or not. This is due to the increased cost associated with an extended duration for storage, whether at multiple independent spent fuel storage installations (ISFSIs) or at an ISF, until waste can be disposed of.- There is a potential total system lifecycle cost avoidance in realistic scenarios with an ISF when compared to scenarios with no ISF. However, most of the cost avoidance occurs several decades after the ISF is opened. The total WMS cost differential over the long term is mainly attributed to the reduced operational costs of storing the fuel in a consolidated facility rather than at individual reactor sites. - Earlier establishment of an ISF allows for more avoidance of post-shutdown at-reactor storage costs for any repository opening date. An ISF allows earlier acceptance of fuel from reactors, which reduces at-reactor costs from a total system perspective. - Transportation costs have little impact on a WMS with or without an ISF. These impacts range from 3-11% of the total cost in all scenarios. Therefore, transporting the fuel twice does not appear to be a significant cost concern driver relative to other system costs. In conclusion, designing, licensing, and constructing an ISF will require a large near-term financial investment. However, reduced annual operating and maintenance costs for an integrated waste management system with an ISF, compared to a system without an ISF, could eventually result in system-wide (integrated) cost avoidance due to reductions in at-reactor storage costs in the long term. The largest cost avoidances would not occur for several decades, so assumptions about inflation, escalation, and discount rates will have a significant effect on potential economic impacts of an ISF. It should be noted that other benefits associated with the investment of an ISF-such as earlier removal of SNF from shutdown reactor sites, earlier prospects for site re-utilization, and additional overall integrated waste management system flexibility-were not addressed in this study. (authors)

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Analysis of the Needs for Long Term Memory and Knowledge Preservation Relating to Radioactive Waste Disposal Facilities - 17213

Proposals for a set of provisions for long-term memory and knowledge to be defined for a radioactive waste disposal facility, near surface or deep underground, address two primary motives, related to two ethical principles. The first motive is to prevent future generations from interfering involuntarily with the repository. This requires maintaining awareness of the repository, and addresses the ethical principle of protection of man and environment. The second motive is to provide future generations all the available relevant information which might help them make informed decisions about intentional actions, and assess the consequences. This requires transmitting detailed knowledge of the repository, and addresses the ethical principle of preservation of freedom of action. The set of provisions to be implemented with respect to each of these motives may not be the same. In order to define and assess the set of provisions, it is also useful to identify the various components of the process of transmission of a given message, or set of messages, to future generations. Three sub-processes have been identified: (i) 'memorization', at the producer stage, where a full set of information to be transmitted is identified, organized and expressed; (ii) 'preservation', where the potential durability of records is extended, the preservation conditions are controlled and where the records may be restored, if their status is degraded; (iii) 'access', at the receiver stage, where the receiver has to be notified of the existence of the information, to find it and to interpret it properly. As a failure of transmission to future generations would result from the failure of any of the subprocesses, a minimal set of provisions may be defined from this decomposition. (authors)

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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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Reviewing Spent Nuclear Fuel Dry Cask Storage Programs to Identify Challenges for an Integrated Waste Management System - 17535

Under the Nuclear Waste Policy Act (NWPA), the U.S. Department of Energy (DOE) has responsibility for removing commercial spent nuclear fuel (SNF) from nuclear power plant sites and disposing of the SNF in a deep geologic repository. However, the methods used by commercial nuclear power plants for onsite storage of their SNF define the starting conditions for DOE efforts to develop a waste management system that includes packaging, transportation, storage, and disposal of commercial SNF. The NWPA (as amended) also charges the U.S. Nuclear Waste Technical Review Board (Board) with evaluating the technical and scientific validity of DOE activities related to the management and disposal of SNF and high-level radioactive wastes (HLW). DOE's efforts related to developing an integrated program for storing, transporting, and disposing of SNF and HLW were the focus of a public meeting held by the Board on August 24, 2016, in Washington, D.C. To prepare for the public meeting, the Board's staff compiled information on the dry cask storage systems in service at nuclear power plant sites in order to identify issues that would need to be addressed by DOE in planning to transport SNF away from the sites. This paper is based on a briefing presented to the Board members by the Board's staff before the public meeting. Post-meeting findings and recommendations of the Nuclear Waste Technical Review Board are documented in the Board letter to the Department of Energy dated December 8, 2016. A note about terminology: in this paper, the phrase 'dry cask storage system' is generic and applies to a complete system used for dry storage of commercial SNF.Within these storage systems, commercial SNF is sealed inside a container called either a cask or a canister depending upon the specific type of storage system used. This distinction is discussed in more detail in the body of this paper. When referring to the containers holding SNF in particular systems, this paper uses the terms 'casks' or 'canisters,' as appropriate. When discussing the collective group of all containers, this paper uses the phrase 'casks and canisters'. Dry cask storage of SNF is a widespread practice throughout the U.S. commercial nuclear industry. As of August 1, 2016, more than 2300 storage casks and canisters were loaded at U.S. commercial nuclear power plant sites. This number is expected to increase by more than 200 casks and canisters annually, reaching a total of approximately 4500 by 2025. Multiple vendors have developed their own unique designs of dry cask storage and transportation systems. The majority of storage system designs (75 percent) feature SNF loaded in welded stainless steel canisters that are stored in ventilated concrete overpacks that allow for convection cooling. Some older dry cask storage system designs do not include a welded stainless steel canister; instead, SNF is loaded directly into a heavily shielded metal cask to minimize radiation exposure to workers and prevent atmospheric release of radionuclides. These types of systems are sealed by O-rings compressed under a bolted lid. After loading, dry cask storage systems are located on concrete pads at Independent Spent Fuel Storage Installations (ISFSI) at nuclear power plant sites and will remain there until the time when they will be transported to a consolidated interim storage facility or a deep geologic repository. Eventual transportation of canistered SNF will include removing the stainless steel canisters from the concrete overpacks, possibly repackaging the SNF, and loading the canisters into specially designed transportation casks for shipment by truck, rail, or barge. In the case of the non-canistered casks, some are approved for transportation and can be shipped after impact limiters are installed on the casks. SNF will need to be removed from casks not approved for transportation and transferred to transport-approved casks. This paper highlights five issues and challenges presented by the nuclear industry's use of dry cask storage systems that will need to be addressed by DOE in developing an integrated waste management system. One example, among the five, is that several dry-storage casks and canisters have received Nuclear Regulatory Commission certificates of compliance for storage only and do not have certificates of compliance for transportation. This will pose a challenge when the SNF must be moved to a consolidated interim storage facility or a deep geologic repository. Another example is that, when loaded with SNF, the total weight of new, larger transportation cask designs will exceed 142 metric tonnes (156 tons) which, when combined with the weight of the rail-car, will exceed the gross weight limit for unrestricted operation on some rail lines. This will also affect future transportation planning for shipments of SNF. All five issues and challenges are discussed in detail in the body of the paper. (authors)

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Status of HLW disposal in the USA and rational, progressive, paths forward based upon lessons learned in the USA and abroad since 1973 - 15103

The development of the USA's only candidate (since 1987) HLW-repository at the Yucca Mountain (YM) site, Nevada, was halted by the Obama administration in 2009. Four years later, the Obama administration proposed a new strategy for the back end of the nuclear fuel cycle that would open a consent-based HLW repository 'by 2048'. At the end of 2014, both the YM HLW repository and the new HLW-disposition (storage and disposal) strategy remain on hold due to lack of enabling legislation. With this as background, and based upon our active involvement in, monitoring of, and reporting on HLW management programs in the USA and abroad since 1973, we submit that: 1. Politics, political will, and legal actions and outcomes will continue to govern progress. 2. Public acceptance and sustained support (PASS) may influence politics and political will. 3. PASS is time-dependent and governed by: a. Ideologies; b. Perceived benefits and risks; c. Level and equity of radiation protection provided by applicable regulations; d. Perceived robustness/safety of the proposed disposition concept; and e. Perceived credibility and competency vested in the involved organizations and their respective leaders (= TRUST). We therefore recommend that the USA concurrently pursues at least two, 'centralized' HLW-storage and -disposal solutions based upon best-available relevant knowledge and majority-PASS at facility-host locations. Furthermore, safe(r) and more secure disposal of defense/government-generated HLW could probably commence at least 15 years earlier than 'by 2048' in/at: 1. The YM repository/site. 2. The WIPP repository/site. 3. 'Local' deep boreholes. (authors)

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Robust disposal concept, uniform regulations, and trust in the messenger; three fundamental building blocks for consent-based HLW-disposal solutions in the USA - 15104

Pending enabling legislation, the USA's HLW-disposal program had been held in political abeyance since 2009 at the crossroads to one or both of the Yucca Mountain candidate (since 1987) HLW-repository in Nevada and/or the consent-based siting of the new HLW-disposal and centralized HLW-storage facilities proposed in 2012; a road not previously travelled. The consent-based siting approach would require the following gap between the reality (A) and the requirement (B) for public trust, acceptance and sustained support (PASS) to be bridged: A. Less than 1% of the general public in any given country fully comprehends the scientific-underpinnings and the projected health risks imposed by a HLW repository. B. More than 50% of the general public in a given geographical area would have to accept to host it from start to end. The following PASS-building blocks, successfully used at the WIPP-site in New Mexico and abroad to get from A to B during the past 30+ years, are thus highly recommended: 1. Defining the consent footprint upon host-county/state boundaries and/or radiation/health-risks and/or to identify/designate the directly affected parties (DAPs). 2. Using databases and lessons-learned by other repository programs to advantage. 3. Presenting the information in terms and/or by examples more readily understood by laypeople, because both their acceptance and opposition/rejection are influenced by: a. The type, number, problems, and status of 'similar' disposal concepts; and b. The level of i. Radiation protection provided by applicable regulations; ii. Involvement and decision-making authority vested in the DAPs; and iii. Their trust in the 'spokesperson/messenger. (authors)

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The role of independent monitoring in maintaining community support through a radiological incident - a WIPP case study - 15107

The Waste Isolation Pilot Plant (WIPP) is a U.S. Department of Energy (DOE) waste repository for the permanent disposal of defense transuranic (TRU) wastes. The repository is mined in the Salado Formation, a bedded salt formation of the Permian era, approximately 655 m (2150 ft.) below land surface. Located near Carlsbad, New Mexico, the WIPP facility is the world's first deep geological disposal facility licensed to accept TRU waste. Environmental monitoring is a key component in the development and operation of any nuclear facility. Well after the WIPP facility had been sited and constructed, but before repository operations began, DOE and local community leaders recognized the value of having an independent environmental monitoring program in addition to the self-monitoring program required by regulation. An independent monitoring organization, the Carlsbad Environmental Monitoring and Research Center (CEMRC) was created by New Mexico State University at its Carlsbad campus. After almost fifteen years of successful waste disposal operations, the first airborne radiation was accidentally released from the WIPP and detected beyond the site boundary on February 14, 2014. The accident released moderate levels of radioactivity into the underground air. A small but measurable amount of radioactivity also escaped to the surface and was detected beyond the site's inner boundary. The results were reported to the public as they were obtained and verified. Releases were low and localized, and no radiation-related health effects among local workers or the public would be expected. CEMRC's independence and its extensive monitoring program played a crucial role in timely informing the local populations on the levels and types of radiation released from the WIPP. CEMRC also helped eliminate unnecessary concern surrounding fear of radiation by engaging local populations through news releases and presentations at 'town hall' meetings sponsored by the Mayor's Office and the Department of Energy. (authors)

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Risk considerations for WIPP passive institutional controls - 15173

The regulatory assurance measures for the Waste Isolation Pilot Plant (WIPP) include such things as active and passive institutional controls, monitoring, waste retrieval/removal capabilities and engineered barriers. Passive Institutional Controls (PICs) are an assurance measure intended to reduce the likelihood of humans unintentionally intruding the WIPP geologic radioactive waste disposal system for thousands of years after it is closed. The waste repository is designed such that it should not pose a significant risk to future populations if it is left undisturbed. The design has also been demonstrated through a performance assessment (PA) analysis to not pose a significant risk to future generations even if it is intruded upon by an inadvertent drilling intrusion [1, Appendix PA]. Through PA, it has been determined that the overall risk of the disposal system to people and the environment is small. The intent of the regulatory Assurance Requirements and PICs is to provide additional confidence that the repository will perform as expected after closure. However, the actual implementation of the proposed PICs design may pose a greater risk to the current population than they would potentially reduce for future generations. Specifically, the risks due to industrial accidents, construction and transportation risks incurred during the fabrication and construction of the permanent markers system may be greater than the overall reduction in risk to future generations due to the existence of the permanent markers. If this were true, implementation of the current PICs design may be counter to the intention of the regulatory requirement to include such assurance measures. As such, provisions for assurance measures used in geologic radioactive waste disposal facilities, such as PICs, should consider risk impacts. A provision of any disposal program's Regulatory Assurance Requirements should address the impacts of the known risks from all the components of the assurance-related systems. The initial WIPP PICs design was developed as part of the regulatory certification process in 1996 with the intent of being revised when the WIPP closes several decades from now [2, Appendix PIC]. The revised design that will be developed at closure should address the design's potential reduction to long-term risks from the repository and the risks due to the implementation of the final design. (authors)

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Knowledge management information tool Web analytics - 15182

The Knowledge Management Information Tool (KM-IT) is a web-based [01] system developed to maintain and preserve the Department of Energy's (DOE's) D and D knowledge base. The system was developed by Florida International University's Applied Research Center (FIU-ARC) with the support of the D and D community including the DOE Office of Environmental Management, and with the active collaboration and support of the DOE's Energy Facility Contractors Group (EFCOG). The KM-IT system is a D and D community driven system tailored to serve the technical issues faced by the D and D workforce across the DOE Complex. The D and D KM-IT is an interactive web-based system operational and available for free access at www.dndkm.org. [02] The D and D KM-IT is currently composed of the following tailored D and D modules: Web Crawler, Hotline, Technology, Document Library (including Hanford's and Savannah River Sites' ALARA Center Reports), Specialist Directory, Lessons Learned, Best Practices, Video/Picture Library, Vendors, Collaboration Tools, Training, and Mobile Systems. The Web Crawler dynamically searches through the D and D KM-IT repository as well as the web and displays search results based on the search criteria. The Hotline allows registered users to post questions/problems related to D and D and to receive solutions from a subject-matter specialist. The Technology module serves as repository of D and D technologies and contains technology/ demonstration fact sheets and vendor information. D and D community members can add Lessons Learned, Best Practices, Documents, and Pictures/Videos to the D and D KM-IT repository, after a formal approval process. The Vendor module provides a directory of commercial vendors who provide D and D related technologies, supplies, and services. D and D KM-IT makes excellent use of the knowledge that exists within the D and D community by allowing D and D project managers around the DOE complex to collaborate by sharing innovative ideas, past experiences, and practices and by maintaining a directory of subject matter specialists. The mobile version of the KM-IT can be accessed from m.dndkm.org [03] and currently has six active modules: Vendor, Technology, Picture/Video Library, Hotline, Lessons Learned and Specialist Directory. Web analytics is a key tool being implemented by the D and D KM-IT project team in an effort to enhance the system to better meet users' needs. The D and D KM-IT project team incorporates web analytics as part of its operational elements to analyze information and key data points on how the system is being used. Web analytics is the measurement, collection, analysis and reporting of internet data for the purposes of understanding and optimizing web usage. The use of web analytics retains or attracts D and D community members to access and share knowledge through virtual collaboration on the KM-IT platform. D and D KM-IT web analytics measures details on the overall usage of the system without tracking personal information or specific user behavior: how many users visited the application, how many of those users were unique visitors, how visitors come to the system (i.e., by following a link to the system or by using the web site URL via bookmark or directly typing the address), what keywords were used to perform searches with the search engine, how long the average user stayed on a given screen or on the entire system and what links were clicked on. This information is used to identify which areas of the system are more popular than the others and provides information that can be used to streamline the application for a better user experience. (authors)

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Influences of temperature on permeability changes of flow-paths altered by highly alkaline Ca-rich groundwater - 15192

Fractures (or cracks) in host rock around the geological repository are considered as main flow-paths for the migration of radionuclides. Such fractures would be altered by the alkaline components (Ca, Na, K) leaching from cementitious materials for the construction of the repository. While silicate minerals in fractures are dissolved by highly alkaline groundwater, secondary minerals would deposit on the surface of fractures because of the reaction between the alkaline components and silicate species. The authors' previous study showed the generation of CSH-gel and the clogging of micro flow-path under the condition of Ca-rich and high pH by flow experiments. The present study examined the permeability changes with temperature in micro flow-path flowing highly alkaline Ca-rich solution, considering temperature at the depth of geological disposal system. For the simulation of micro flow-path such as fractures, 'micro flow-cell', which nipped a thin Teflon sheet with a slit between granite chip and Teflon basement, were used for the experiments. Highly alkaline Ca-rich solution (pH>12 and 8.5 mM Ca(OH){sub 2}) were injected into micro flow-cell with 2.0 ml/h of flow rate under the given temperature conditions (278 K, 296 K or 313 K). As a result, the permeability became lower with the increase in temperature. In addition, the deposition rates of CSH-gel became larger with the increase in temperature, and the activation energy was estimated to be 32.0 kJ/mol. These results suggest that flow-paths around the geological repository would undergo the clogging with CSH-gel in a shorter time-period under a condition of higher temperature. (authors)

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Effects of pH on deposition rate of supersaturated silicic acid around geological disposal system - 15245

For the migration assessment of radionuclides around geological repository, it is important to estimate the dynamic behavior of silicic acid under a high alkalinity condition due to the cementitious materials for the construction of the repository. This study examined the pH dependencies of the deposition behavior of supersaturated silicic acid in the co-presence of solid phase. The parameters for the deposition experiments were as follow: the pH was set to 8, 9 and 10, the initial saturated concentration was set to 2-8 mM, the amount of amorphous silica (350 m{sup 2}/g) as solid phase was set to 0.1-1.0 g. The experimental results showed that the initial supersaturated concentrations strongly affected the formation of colloidal silicic acid, increasing the deposition amount of silicic acid and decreasing the soluble silicic acid with time. In other words, the polymerization and the deposition of silicic acid simultaneously arose in these experiments. Furthermore, this study evaluated the apparent deposition rates of silicic acid by assuming the first-order reaction equation considering the specific surface area. As a result, the deposition rate constants, k, were in a narrow range of 10{sup -11} to 10{sup -10} m/s under all experimental conditions in this study. This means that the deposition rate constants do not depend both on pH-value (in the range from 8 to 10) and the initial concentration of supersaturated silicic acid. That is, the estimated deposition rate constants are useful in estimation of the deposition behavior of supersaturated silicic acid, such as the clogging in fractures (flow-paths) around the repository, even if the pH-value of groundwater gradually or dramatically changes. (authors)

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