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This technical paper reflects concepts which could support future decision-making by DOE. No inferences should be drawn from this paper regarding future actions by DOE. To the extent this technical paper conflicts with provisions of the Standard Contract, those provisions prevail. Cost Implications of an ISF in the WMS September 2016 iii HISTORY OF CHANGE Rev. 0 (Draft) Initial Issuance on 01-30-2015. Rev. 1 Revised to incorporate comments from Department of Energy.

SUMMARY Introduction and ObjectivesIn the 1990s the U.S. Department of Energy (DOE) completed a number of system analyses investigating consolidated interim storage as a part of the waste management solution. These analyses are "dated" and do not reflect the present situation regarding at-reactor used nuclear fuel (UNF) management, alternatives for away from reactor management of used nuclear fuel, and alternatives for the ultimate disposal of UNF. The Blue Ribbon Commission for America's Nuclear Future and the Nuclear Waste Technical Review Board have also pointed out the need for such analyses.The Used Fuel Management System Architecture Evaluation effort provides the DOE and others with information regarding the various alternatives for managing UNF generated by the current fleet of light water reactors operating in the U.S. The objectives are to:• Provide quantitative information with respect to a broad range of UNF management alternatives and considerations• Develop an integrated approach to evaluating storage, transportation, and disposal options, with emphasis on flexibility• Evaluate impacts of storage choices on UNF storage, handling, and disposal options• Identify alternative strategies and evaluate with respect to cost and flexibility• Consider a broad range of factors including repository emplacement capability, thermal constraints, repackaging needs, storage and transportation alternatives, and impacts on utility operations.In Fiscal Year 2012 system-level analyses of the overall interface between at-reactor, consolidated storage, and ultimate disposition along with the development of supporting logistic simulation tools were initiated. The objective of the Fiscal Year 2012 effort was two-fold: 1) develop methodologies, approaches, and tools (capability development), and 2) evaluate select UNF disposition scenarios (capability demonstration). The scenarios chosen for evaluation and the assumptions, inputs, and boundary conditions selected allowed for an initial set of analyses to gain insight regarding integrated system dynamics and an understanding of trends. This initial set of analyses also points to where additional system architecture analyses should focus. R&D OverviewAn important waste management system interface consideration is the need for ultimate disposal of UNF fuel assemblies contained in waste packages sized to be compatible with the geologic medium of the final repository. Thermal analyses completed by the Used Fuel Disposition Campaign indicate that waste package sizes for the geologic media under consideration by the Used Fuel Disposition Campaign are significantly smaller than the canisters being used for on-site dry storage by the nuclear utilities. Therefore, at some point along the UNF disposition pathway there may be a need to re-package fuel assemblies already loaded into the types of dry storage canisters currently in use unless the feasibility of direct disposal of these large canisters can be demonstrated. Note that evaluating the feasibility of the direct disposal of dual...

Utilities worldwide are using dry-cask storage systems to handle the ever-increasing number of discharged fuel assemblies from nuclear power plants. In the United States and possibly elsewhere, this trend will continue until an acceptable disposal path is established. The recent Fukushima nuclear power plant accident, specifically the events with the storage pools, may accelerate the drive to relocate more of the used fuel assemblies from pools into dry casks. Many of the newer cask systems incorporate dual-purpose (storage and transport) or multiple-purpose (storage, transport, and disposal) canister technologies. With the prospect looming for very long term storage — possibly over multiple decades — and deferred transport, condition- and performance-based aging management of cask structures and components is now a necessity that requires immediate attention. From the standpoint of consequences, one of the greatest concerns is the rupture of a substantial number of fuel rods that would affect fuel retrievability. Used fuel cladding may become susceptible to rupture due to radial-hydride-induced embrittlement caused by water-side corrosion during the reactor operation and subsequent drying/transfer process, through early stage of storage in a dry cask, especially for high burnup fuels. Radio frequency identification (RFID) is an automated data capture and remote-sensing technology ideally suited for monitoring sensitive assets on a long-term, continuous basis. One such system, called ARG-US, has been developed by Argonne National Laboratory for the U.S. Department of Energy’s Packaging Certification Program for tracking and monitoring drums containing sensitive nuclear and radioactive materials. The ARG-US RFID system is versatile and can be readily adapted for dry-cask monitoring applications. The current built-in sensor suite consists of seal, temperature, humidity, shock, and radiation sensors. With the universal asynchronous receiver/transmitter interface in the tag, other sensors can be easily added as needed. The system can promptly generate alarms when any of the sensor thresholds are violated. For performance and compliance records, the ARGUS RFID tags incorporate nonvolatile memories for storing sensory data and history events. Over the very long term, to affirmatively monitor the condition of the cask interior (particularly the integrity of cover gas and fuel-rod cladding), development of enabling technologies for such monitoring would be required. These new technologies may include radiation-hardened sensors, in-canister energy harvesting, and wireless means of transmitting the sensor data out of the canister/cask.

The activity of Phase I of the Waste Management Working Group under the United States-Japan Joint Nuclear Energy Action Plan started in 2007. The US-Japan JNEAP is a bilateral collaborative framework to support the global implementation of safe, secure, and sustainable, nuclear fuel cycles (referred to in this document as fuel cycles). The Waste Management Working Group was established by strong interest of both parties, which arise from the recognition that development and optimization of waste management and disposal system(s) are central issues of the present and future nuclear fuel cycles. This report summarizes the activity of the Waste Management Working Group that focused on consolidation of the existing technical basis between the U.S. and Japan and the joint development of a plan for future collaborative activities. Firstly, the political/regulatory frameworks related to nuclear fuel cycles in both countries were reviewed. The various advanced fuel cycle scenarios that have been considered in both countries were then surveyed and summarized. The working group established the working reference scenario for the future cooperative activity that corresponds to a fuel cycle scenario being considered both in Japan and the U.S. This working scenario involves transitioning from a once-through fuel cycle utilizing light water reactors to a one-pass uranium-plutonium fuel recycle in light water reactors to a combination of light water reactors and fast reactors with plutonium, uranium, and minor actinide recycle, ultimately concluding with multiple recycle passes primarily using fast reactors. Considering the scenario, current and future expected waste streams, treatment and inventory were discussed, and the relevant information was summarized.