Patent Number: 058621954
Section: summary

BACKGROUND OF THE INVENTION 108 nuclear power plants operate in the U.S. without any servicing off-site facility for storage of their spent nuclear fuel rods. When fuel rods can no longer efficiently produce steam, they are taken out of commission and are immediately put into under water storage at a power plant pool where the water absorbs the inherently generated heat. In time the fuel rods decay and the heat generation diminishes. After five years the fissile material is sufficiently spent (decayed/transformed) such that the fuel rods can be stored unconfined in an open air arena. A permanent spent fuel storage facility is planed in the Yucca Mountain region of Nevada. Until then, a "Monitored Retrievable Storage" (MRS) facility is being sought for the intermediate storage of the spent fuel. The author of this patent has worked on many varieties of nuclear material transport equipment and facilities for nuclear fuel since 1958. U.S. Pat. No. 5,448,604 describes an "MRS" facility serviced with railroad equipment. STATEMENT OF THE ART Spent fuel from power plant operation is put into water pools for dissipation of heat as it decays in storage. After about five years or more of radioactive decay, the spent fuel may be stored in the open air using ambient air convection cooling. Eight schemes for intermediate storage have culminated into the "MRS" concept where bundles of spent fuel rods are sealed in a thick steel walled cylinder called a multi-purpose-canister "MPC". In the traditional "MRS" scheme, the "MPC"s are encapsulated in two feet thick concrete and placed in open, outside storage. The concrete casks have provisions for convection air over the exterior surface of the "MPC"s for cooling. The dry-pool invention is an intermediate scheme having a pool having an air manifold system for providing external surface air cooling when the traditional pool water is removed. The facility's roof, walls and access openings are configured to confine the radiation emitting from the "MPC"s being stored. This radiation would otherwise be being absorbed in the conventional pool water. The facility is un-manned and is operated remotely as is the inventors previous storage facility described in U.S. Pat. No. 5,448,604, Sep. 5, 1995. An elevation chase sets and controls the fall height of an "MPC" to a stopping media as it is lowered (placed) or removed from the dry-pool. Before fuel rods are taken from a utility plant water-pond they grouped and put into an "MPC". The fuel rod laden "MPC" is transported from its water storage pool via an appropriate compilation of bridge crane and transporters. Transporters may included a railroad haul in a RR-car having radiation shielding and securement to prevent the "MPC" from tipping. BRIEF SUMMARY OF THE INVENTION Spent nuclear fuel is confined in welded sealed fuel rods. After fuel deterioration, these spent fuel rods are housed in welded, sealed closed multi-purpose canisters "MPC". An "MPC" is typically five (5') feet in diameter and stands 16 feet tall. The invention is an integrated transport, placement, and monitored storage and retrievable facility for the "MPC"s containing the nuclear spent fuel. "MPC"s from a water storage pool are transported from the plant water pool to a dry-pool for storage. Throughout the transfer, the "MPC" is appropriately surrounded with radiation shielding to prevent inappropriate exposure both into and out of the system. Typically an "MPC" is taken from the water storage pool, placed in a shielded transport device (shielded RR-car). Shielded in the transporter, the "MPC" is moved from the plant pool location to the dry-pool location. With the transporter adjacent to the dry-pool, the "MPC" is lifted with a bridge crane and moved sideways out through doors, moved through a shielded corridor adjacent to the dry-pool, then the "MPC" enters the dry-pool, and is then moved in the dry-pool to a storage place on the floor of the dry-pool. When putting an "MPC" into the dry-pool, where there is a significant elevation change, an elevation chase follows the "MPC" such that it may never be subject to a free fall elevation drop of more than 18 inches. One form of the elevation chase of this invention is a column of water where the column of water is lowered below the "MPC" as the "MPC" is lowered to the dry-pool floor. When the MPC approaches the dry-pond floor, the water is then out of the elevation chase and water lock gates are opened to allow the bridge crane to move the lowered to the floor "MPC" to move it about the dry-pool floor to a selected storage location. Each storage location has an in-floor inlet air manifold from an outside air source so that a natural convection of cooling air moves up the sides of the fuel heated "MPC". The natural temperature rise of "MPC" surface heated air continuously pulls in outside air which cools the "MPC". The cooling air rises above the dry-pool and exits out from under the dry-pool building roof, flowing out an end of the building. Under the roof, two ends of the dry-pool are open to the atmosphere to encourage a flow of air across and above the dry-pool. The inlet air manifold is constructed such that should the dry-pool be filled with water, the air manifold also fills with water but water does not leak out of the manifold. The casks are stored secure from tipping with a seismic brace which swings out from a wall and secures the top of the cask to wall to prevent it from tipping in a seismic occurrence. The casks are stored in a designed matrix. The matrix has specific individual storage location addresses for the placement of each casks according to an X-Y Cartesian measured location. The exact address location for each cask is recorded at a control center data base when the cask is placed. Each cask is systematically and routinely monitored for its condition in storage and the tested results are automatically transmitted to and recorded in an off site data base. The data is automatically reviewed and analyzed for a problem condition. When a problem situation is determined, appropriate personnel are automatically notified so that corrections may be implemented.