AMERICAN NUCLEAR SOCIETY NINTH INTERNATIONALTOPICAL MEETING ON ROBOTICS AND REMOTE SYSTEMS

摘要

The US Department of Energy (DOE) is currently evaluating the Yucca Mountain Nevada site forrnsuitability as a Monitored Geologic Repository (MGR) for underground disposal of 70,000 metric ton ofrnthe nation’s high-level waste. This paper reviews the remote handling, engineering, safety, and economicrntrade-off studies leading to the development, conceptual design, viability assessment, and siternrecommendation decisions for the repository. Trade-off considerations studied include a number ofrnremote handling and high-level radioactive waste packaging facility design alternatives such as truckrnversus rail transport, wet versus dry handling, contact versus remote operation, methods to stage fuelrnassemblies and canisters, manual versus remote maintenance, and modular versus integrated buildingrnconstruction. These trade-off studies have led to design of seven primary waste handling systems tornaccomplish the repository mission of safe handling, reliable remote equipment, cost-effective operations,rnhigh throughput rates, and a minimum of facility outages. Those trade-off decisions that are beingrnreconsidered or reevaluated for the license application phase of the design are also discussed.rnThe results from trade-off studies conducted to date are summarized and the design concepts developedrnfor the repository site recommendation are presented. Waste shipments arrive at the security station nearrnthe North Portal to the underground MGR. After receipt inspections and checks, truck or rail cask carriersrnare staged in a controlled area surrounding the MGR nuclear facilities. The cask personnel barriers andrnimpact-limiters are removed in a Carrier Preparation Building prior to transporting the cask and carrier tornthe Waste Handling Building (WHB). Remote handling and packaging operations are performed in thernWHB. Casks are unloaded from their carriers in a large carrier bay. Commercial spent nuclear fuel casksrnare transferred to an Assembly Transfer System where they are placed in unloading pools for remoternunderwater fuel handling. The spent fuel assemblies are staged in connected pools until they arernremotely transferred to hot cells for loading into a disposal container. DOE-owned spent fuel and highlevelrnwaste canisters and casks are transferred to a Canister Transfer System where the casks arernopened, transported into hot cells, and the canisters are transferred remotely to a staging area or arndisposal container. Once a disposal container is loaded, it is transferred to a Disposal ContainerrnHandling System where disposal container lids are welded, annealed and/or inspected remotely in a largernhot cell. The sealed waste package is then staged and loaded, remotely and horizontally, into a shieldedrnwaste package transporter for underground MGR waste emplacement operations.