摘要:
An active zone includes a homogeneous uranium-plutonium nitride fuel, the mass fraction of which is a minimum 0.305, and consists of central, intermediate and peripheral parts which form fuel assemblies comprising fuel elements with geometrically identical shells but differing heights. The radial distribution of the fuel across the volume of the active zone has a stepped shape. The radius of the central part is from 0.4 to 0.5 of the effective active zone radius, while the height of the fuel column in the fuel elements in the central part is from 0.5 to 0.8 of the height of the fuel column in the peripheral part. The heights of the fuel columns forming a stepped intermediate part for diameters ranging from 0.5 to 0.85 of the effective active zone diameter are within the range from 0.55 to 0.9 of the height of the fuel column in the peripheral part.
摘要:
A zirconium alloy nuclear reactor cylindrical cladding has an inner Zr substrate surface (10), an outer volume of protective material (22), and an integrated middle volume (20) of zirconium oxide, zirconium and protective material, where the protective material is applied by impaction at a velocity greater than 340 meters/second to provide the integrated middle volume (20) resulting in structural integrity for the cladding.
摘要:
In a nuclear power plant, a corrosion-resistant oxide film on a surface of the metal component of a reactor structure is exposed to a high-temperature water, the corrosion-resistant oxide film containing an oxide having a property of a P-type semiconductor, and a catalytic substance having a property of an N-type semiconductor is deposited on the oxide film. The oxide film maintains the property of the P-type semiconductor.
摘要:
A method for protecting the components of the primary system of a boiling water reactor, especially against stress cracking corrosion, includes feeding a reducing agent into the primary coolant in order to reduce the number of substances having a oxidizing effect or in order to modify the electrochemical potential of the component surfaces covered with an oxide layer to negative values. An alcohol that can be oxidized in the conditions of a reactor is fed in as a reducing agent, preferably in a liquid form, into the primary coolant. The component surfaces are provided with a blank coating or a single intrinsic oxide coating.
摘要:
A water reactor fuel cladding tube (4) is described. The tube (4) comprises an outer layer (6) of a first zirconium based alloy and has metallurgically bonded thereto an inner layer (7) of a second zirconium based alloy. The inner layer protects (7) the cladding tube (4) against stress corrosion cracking. The second zirconium based alloy comprises tin as an alloying material, and each one of the zirconium based alloys comprises at least 96 percent by weight zirconium. The first zirconium based alloy comprises at least 0.1 percent by weight niobium. A method of manufacturing the cladding tube (4) is also described and comprises the step of co-extruding two tubes of different zirconium based alloys to produce the cladding tube (4).
摘要:
Example embodiment damping devices may include a housing capturing a piston. The housing may be filled and/or able to be filled with a damping fluid compatible with the nuclear reactor coolant, so that a leak from the housing or coolant passing into the housing does not damage the reactor or example embodiment devices. Example embodiments may further include one or more springs that provide an elastic force opposing movement between the piston and housing. A shaft of the piston and an end of the housing may be connected to two nuclear reactor components with relative motion or vibration to be damped. Example methods may use example embodiment damping devices to reduce and/or prevent relative motion and vibration among components of a nuclear reactor.
摘要:
A T-shaped pipe fitting element comprises a main tubular branch having first and second ends for connection to first and second pipe fitting sections of an auxiliary circuit, respectively, and a lateral branch having an axis which is at an angle to the axis of the main branch, and a free end for connecting to a third pipe fitting section of the auxiliary circuit. The first, second, and third pipe fitting sections each have different functions. One supplies the pipe fitting element with a first fluid at a high temperature, another supplies a second fluid to the pipe fitting element, at a lower temperature than the first fluid, and the third discharges a mixture of the first and second fluids. The pipe fitting sections consist of austenitic stainless steel. The T-shaped pipe fitting consists of stainless martensitic steel with improved thermal endurance properties.
摘要:
The subject of the present invention is: a casing internal part (1) suitable for the dry intermediate storage of at least one irradiated fuel element. Said casing internal part (1) has a tiered structure which comprises at least two superposed modules (M1, M2, M3, M4), each of said modules (M1, M2, M3, M4), made of a material that is a good conductor of heat, with compartment(s) (2a, 2b) for accommodating said fuel element(s) in the central part and with at least one hollowed-out peripheral heat sink (3a, 3b), being arranged on a support plate (4) that is perforated to allow said fuel element(s) through; the perforated support plates (4) of said structure being positioned and assembled by means of a retaining system (5′+5+5″), with a clearance (J) left between the top of the module of one tier (Mi) and the perforated support plate (4) of the tier (Mi+1) immediately above; a temporary storage casing (10) equipped with such a casing internal part (1); and the corresponding temporary storage method.
摘要:
A fullerene molecule having one or more free thermal neutrons trapped within the fullerene molecule and a method for trapping and storing neutrons within a fullerene molecule are described.
摘要:
A method for production of a fuel cladding tube for a nuclear reactor, characterized by the preparation of an ingot of an alloy of zirconium with the following composition by weight %: 0.8%≦Nb≦2.8%, traces≦Sn≦0.65%, 0.015%≦Fe≦0.40%, C≦100 ppm, 600 ppm≦O≦2300 ppm, 5 ppm≦S≦100 ppm, Cr+V≦0.25%, Hf≦75 ppm and F≦1 ppm the remainder being zirconium and impurities arising from production. The ingot is then subjected to forging, a hardening and thermomoechanical treatments comprising cold laminations separated by intermediate annealing, all intermediate annealings being carried out at a temperature below the α→α+β transition temperature of the alloy, finishing with a recrystallization annealing and resulting in the production of a tube, whereupon an optional external cleaning of the tube is carried out and a mechanical polishing of the external surface of the tube is carried out to give a roughness Ra less than or equal to 0.5 μm. The invention further relates to a fuel cladding tube obtained thereby.