Patent application number | Description | Published |
20090252278 | NUCLEAR REACTOR (ALTERNATIVES), FUEL ASSEMBLY OF SEED-BLANKET SUBASSEMBLIES FOR NUCLEAR REACTOR (ALTERNATIVES), AND FUEL ELEMENT FOR FUEL ASSEMBLY - The invention relates to light water reactor designs in which thorium is used as fuel and in particular to designs of jacketless fuel assemblies, which make up the cores of pressurized water reactors (PWRs) such as the VVER-1000. Nuclear reactor cores containing seed and blanket subassemblies that make up the fuel assemblies are used to burn thorium fuel together with conventional reactor fuel that includes nonproliferative enriched uranium, as well as weapons-grade and reactor-grade plutonium. In the first alternative, the reactor core is fully “nonproliferative,” since neither the reactor fuel nor the wastes generated can be used to produce nuclear weapons. In the second version of the invention, the reactor core is used to burn large amounts of weapons-grade plutonium together with thorium and provides a suitable means to destroy stockpiles of weapons-grade plutonium and convert the energy released to electric power. The cores in both embodiments of the invention are made up of a set of seed-blanket assemblies, which have central seed areas surrounded by annular blanket areas. The seed areas contain uranium or plutonium fuel rods, while the blanket areas contain thorium fuel rods. The volume ratio of moderator to fuel and the relative sizes of the seed area and the blanket area have been optimized so that neither embodiment of the invention generates wastes that can be used to produced nuclear weapons. A new refueling system is also used for the first embodiment of the invention to maximize recycling of the seed fuel; the system also ensures that the spent nuclear fuel cannot be used to produce nuclear weapons. | 10-08-2009 |
20110255651 | NUCLEAR REACTOR (ALTERNATIVES), FUEL ASSEMBLY OF SEED-BLANKET SUBASSEMBLIES FOR NUCLEAR REACTOR (ALTERNATIVES), AND FUEL ELEMENT FOR FUEL ASSEMBLY - Fuel elements are supported by fuel assemblies configured for use in land-based nuclear reactors such as the VVER-1000. The fuel elements include a kernel having a multi-lobed profile that forms spiral ribs that include fissionable material (e.g., uranium or plutonium), a central metal displacer extending along a longitudinal axis of the kernel, and a metal cladding (e.g., zirconium and/or other refractory metals) enclosing the kernel. The fuel element may be fabricated by joint extrusion of the displacer, kernel, and cladding through a die to metallurgically bond the kernel and cladding. | 10-20-2011 |
20110311016 | LIGHT-WATER REACTOR FUEL ASSEMBLY (ALTERNATIVES), A LIGHT-WATER REACTOR, AND A FUEL ELEMENT OF FUEL ASSEMBLY - A 17×17 jacketless fuel assembly for a PWR-type light-water reactor uses thorium as the fuel. The fuel assembly has a square shape in the plan view, a seed region, a blanket region that encircles it, an upper nozzle, and a lower nozzle. The fuel elements of the seed region re arranged in the rows and columns of a square coordinate grid and have a four-lobed profile that forms spiral spacer ribs along the length of a fuel element. The blanket region contains a frame structure within which a bundle of fuel elements made from thorium with the addition of enriched uranium is positioned. The blanket region fuel elements are arranged in the two or three rows and columns of a square coordinate grid. | 12-22-2011 |
20130322591 | FUEL ASSEMBLY - Nuclear fuel assemblies include fuel elements that are sintered or cast into billets and co-extruded into a spiral, multi-lobed shape. The fuel kernel may be a metal alloy of metal fuel material and a metal-non-fuel material, or ceramic fuel in a metal non-fuel matrix. The fuel elements may use more highly enriched fissile material while maintaining safe operating temperatures. Such fuel elements according to one or more embodiments may provide more power at a safer, lower temperature than possible with conventional uranium oxide fuel rods. The fuel assembly may also include a plurality of conventional UO2 fuel rods, which may help the fuel assembly to conform to the space requirements of conventional nuclear reactors. | 12-05-2013 |
20140334595 | FUEL ASSEMBLY - Nuclear fuel assemblies include non-symmetrical fuel elements with reduced lateral dimensions on their outer lateral sides that facilitate fitting the fuel assembly into the predefined envelope size and guide tube position and pattern of a conventional nuclear reactor. Nuclear fuel assemblies alternatively comprise a mixed grid pattern that positions generally similar fuel elements in a compact arrangement that facilitates fitting of the assembly into the conventional nuclear reactor. | 11-13-2014 |
Patent application number | Description | Published |
20120325472 | HETEROGENEOUS PROPPANT PLACEMENT IN A FRACTURE WITH REMOVABLE EXTRAMETRICAL MATERIAL FILL - A method of heterogeneous proppant placement in a subterranean fracture is disclosed. The method comprises injecting well treatment fluid including proppant ( | 12-27-2012 |
20130014946 | HYDRAULIC FRACTURING SYSTEMAANM Makarychev-Mikhailov; Sergey MikhailovichAACI St. PetersburgAACO RUAAGP Makarychev-Mikhailov; Sergey Mikhailovich St. Petersburg RUAANM Hutchins; Richard D.AACI Sugar LandAAST TXAACO USAAGP Hutchins; Richard D. Sugar Land TX USAANM Fredd; Christopher N.AACI AshvilleAAST NYAACO USAAGP Fredd; Christopher N. Ashville NY US - A method is given for fracturing a formation, in particular far-field in a tight formation, in which at least a portion of the proppant is crushable in situ at some point during pumping, during fracture closure, or at higher Fluid flow stresses experienced later during fracture closure. The closure stress or hydrostatic stress is estimated, then a proppant is selected that is at least partially crushable at that closure stress, and then the fracturing treatment is performed with at least a portion of the total proppant being the selected crushable proppant. | 01-17-2013 |
20130048283 | Subterranean Reservoir Treatment Method - A method is given for heterogeneous proppant placement in fracturing by in situ aggregation of fine mesh proppant particulates or other materials such as fibers in a subterranean fracture. A polymer is injected into a subterranean formation and is subsequently subjected to a chemical reaction, for example hydrolysis, under downhole conditions, which leads to formation of either a cationic or an anionic polyelectrolyte. Alternatively, the polyelectrolyte is synthesized downhole by, for example, a Hofmann degradation or a Mannich reaction. The polyelectrolyte acts as a flocculant and provides aggregation of solid particulates such as sand, mica, silica flour, ceramics and the like, which leads to formation of proppant micropillars deep in the fracture. Methods of aggregation of fibers to enhance bridging, and other applications of controlled flocculation are also given. | 02-28-2013 |
20130056213 | Heterogeneous Proppant Placement - A method is given for inducing heterogeneous proppant placement in a hydraulic fracture in a subterranean formation by causing proppant aggregation through a gel phase transition or chemical transformation in the proppant carrier fluid. Proppant aggregation may be induced by causing or allowing syneresis of the polymer gel that viscosifies the fluid; formation of a polyelectrolyte complex from cationic and anionic polymers included in or created in, the fluid; and by increasing the temperature of the fluid above the critical solution temperature of a polymer in the fluid. The proppant carrier fluid may be formulated such that these transformations occur naturally during or after proppant injection, and the transformations may be chemically triggered or delayed. | 03-07-2013 |
20130105157 | Hydraulic Fracturing Method | 05-02-2013 |
20130161003 | PROPPANT PLACEMENT - Embodiments of hydraulic fracturing methods disclosed herein use fine mesh proppant. In one embodiment the method is used to fracture a low permeability formation. In one embodiment the method uses flocculation to improve conductivity of a fracture. In one embodiment fluid flow through the fine mesh proppant in the fracture creates a network of connected channels to improve the fracture conductivity. | 06-27-2013 |