Office Of Civilian Radioactive Waste Management Research Articles

Progress in permanent geologic disposal of spent nuclear fuel and high-level radioactive waste in the United States

The mission of the Office of Civilian Radioactive Waste Management (OCRWM) of the US Department of Energy (DOE) is to manage and dispose of spent nuclear fuel and high-level radioactive waste in a manner that protects health, safety and the environment, enhances national and energy security and merits public confidence. Consolidation of spent nuclear fuel and high-level radioactive waste from 126 sites in 39 states and safe disposal at Yucca Mountain are vital to the US national interests. The US geologic repository programme's key objective remains to begin receiving spent nuclear fuel and high-level radioactive waste at the US Nuclear Regulatory Commission (NRC) licensed Yucca Mountain repository in 2010. To achieve this objective, the DOE must, in less than 7 years, seek and secure authorization to construct the repository from the NRC, begin constructing the repository and receive a license amendment allowing receipt of radioactive materials and operation of the repository. DOE must also develop a transportation system to ship spent nuclear fuel and high-level radioactive waste from civilian and defence storage sites to the repository. This paper describes near-term efforts in developing the license application and transportation system. Successfully licensing, constructing and operating a repository will rely on information gained from more than two decades of scientific investigations at the Yucca Mountain site, all of which contribute to the technical basis for understanding the repository system. This paper also summarizes ongoing and completed in situ testing in the exploratory studies facility (ESF) and cross-drift. The ESF, a U-shaped tunnel approximately 7.9 km long and about 300 m below the crest of Yucca Mountain, has been used extensively to conduct tests in 13 alcoves and niches and to access a smaller cross-drift, 5 m in diameter and 2.7 km long.

3.3.2 Design Concept Evaluation Using System Throughput Model

AbstractThe U.S. Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM) is currently developing the technical bases to support the submittal of a license application for construction of a geologic repository at Yucca Mountain, Nevada to the U.S. Nuclear Regulatory Commission. The Office of Repository Development (ORD) is responsible for developing the design of the repository surface facilities for the handling of spent nuclear fuel and high level nuclear waste. Preliminary design activities are underway to sufficiently develop the repository surface facilities design for inclusion in the license application. The design continues to evolve to meet mission needs and to satisfy both regulatory and program requirements.A system engineering approach is being used in the design process since the repository facilities are dynamically linked by a series of sub‐systems and complex operations. In addition, the repository facility is a major system element of the overall waste management process being developed by the OCRWM. Such an approach includes iterative probabilistic dynamic simulation as an integral part of the design evolution process. A dynamic simulation tool helps to determine if: the mission and design requirements are complete, robust, and well integrated; the design solutions under development meets the design requirements and mission goals; opportunities exist where the system can be improved and/or optimized; proposed changes to the mission and design requirements have a positive or negative impact on overall system performance and if the design changes may be necessary to satisfy these changes. This paper will discuss the type of simulation employed to model the waste handling operations. It will then discuss the process being used to develop the Yucca Mountain surface facilities model. The latest simulation model and the results of the simulation and how the data was used in the design evolution process will also be discussed. Since the use of dynamic simulation is iterative and integral to the design effort, future activities will also be summarized. The paper will close discussing lessons learned from applying dynamic simulation to designing complex systems, and will discuss what pitfalls to avoid and recommendations for developing flexibility in system model development.

Natural system issues in the OCRWM program : Eriksson, L G; Pentz, D L Proc 1st Annual Topical Meeting on High Level Radioactive Waste Management, Las Vegas, 8–12 April 1990V1, P10–19 Publ ANS/ASCE: La Grange Park, 1990

Twenty four site characterization Issues, most of which pertain to the natural system, are presently defined in the Office of Civilian Radioactive Waste Management (OCRWM) Program for the development of a mined geologic disposal system (MGDS) for spent nuclear fuel and other high-level radioactive waste (HLW) at the Yucca Mountain site. Notwithstanding their importance to the successful licensing and timely development of an MGDS, this paper suggests that the overriding natural system question in the OCRWM Program is the attainability of the levels of confidence in MGDS performance required by current licensing regulations. These confidence levels may not be attainable for a natural system unless it is fully integrated with an engineered-barriers system (EBS). Therefore, this paper discusses the potential attainability, or rather unattainability, of existing licensing regulations and outlines an alternative licensing strategy, the As Safe As Reasonably Achievable (ASARA) licensing strategy, that could be employed to optimize the EBS and be compatible with the uncertainties of the natural system.

Radioactive Material Package Seal Tests

General design or test performance requirements for radioactive materials (RAM) packages are specified in Title 10 of the US Code of Federal Regulations Part 71 (US Nuclear Regulatory Commission, 1983). The requirements for Type B packages provide a broad range of environments under which the system must contain the RAM without posing a threat to health or property. Seals that provide the containment system interface between the packaging body and the closure must function in both high- and low-temperature environments under dynamic and static conditions. A seal technology program, jointly funded by the US Department of Energy Office of Environmental Restoration and Waste Management (EM) and the Office of Civilian Radioactive Waste Management (OCRWM), was initiated at Sandia National Laboratories. Experiments were performed in this program to characterize the behavior of several static seal materials at low temperatures. Helium leak tests on face seals were used to compare the materials. Materials tested include butyl, neoprene, ethylene propylene, fluorosilicone, silicone, Eypel, Kalrez, Teflon, fluorocarbon, and Teflon/silicone composites. Because most elastomer O-ring applications are for hydraulic systems, manufacturer low-temperature ratings are based on methods that simulate this use. The seal materials tested in this program with a fixture similar to a RAM cask closure, with the exception of silicone S613-60, are not leak tight (1.0 {times} 10{sup {minus}7} std cm{sup 3}/s) at manufacturer low-temperature ratings. 8 refs., 3 figs., 1 tab.