Methodologies and manufacturing processes to manufacture components by electron beam melting additive manufacturing, particularly components of molybdenum or a molybdenum-based alloy and particularly of complex nuclear component geometries. Input parameters are provided for controlling electron beam melting additive manufacturing equipment, such as electron beam melting machines. The input parameters relate to various process steps, including build set-up, initial thermal treatment, initial layering of powder, pre-consolidation thermal treatment, consolidation, post-consolidation thermal treatment, indexing of layers, and post-build thermal treatment. The methodologies and manufacturing processes allow manufacture of components of molybdenum having a purity of ≥99.0% and a density of ≥99.75%. Metallographic cross-sections of the manufactured molybdenum components were porosity-free and crack-free.

Methodologies and manufacturing processes to manufacture components by electron beam melting additive manufacturing, particularly components of molybdenum or a molybdenum-based alloy and particularly of complex nuclear component geometries. Input parameters are provided for controlling electron beam melting additive manufacturing equipment, such as electron beam melting machines. The input parameters relate to various process steps, including build set-up, initial thermal treatment, initial layering of powder, pre-consolidation thermal treatment, consolidation, post-consolidation thermal treatment, indexing of layers, and post-build thermal treatment. The methodologies and manufacturing processes allow manufacture of components of molybdenum having a purity of ≥99.0% and a density of ≥99.75%. Metallographic cross-sections of the manufactured molybdenum components were porosity-free and crack-free.

A closed-vessel molten salt reactor (cvMSR) is described herein. A cvMSR may comprise a suspended container, such as a metallic container, within a trench surrounded by a concrete enclosure and a concrete cover having a number of channels. The suspended container may be hollow and a solution of fissile materials and salt materials may be provided within the suspended container. The solution may be capable of undergoing a chain reaction nuclear fission process once a threshold temperature is reached. Heat generated by the solution may heat a fluid surrounding the suspended container. The heated fluid may be transported, through the number of channels of the concrete cover, to an external location where the heated fluid may be used in distributing heat and/or electricity generation.

The end plug includes two parts in the form of coaxial cylinders having different diameters, the diameter of the part configured to be arranged inside the cladding is less than the cladding inner diameter by 0.06-0.08 and 2-3 mm, respectively, for interposing brazes of different types. An end plug according to the third variant is composed of three parts in the form of three successively arranged coaxial cylinders having different diameters, the diameter of the two parts configured to be arranged inside the cladding being less than the cladding inner diameter by 0.06-0.08 and 2-3 mm, respectively, for interposing brazes of two types simultaneously. The effects of the invention are safety for the environment, possibility of using the developed end plugs as an alternative for replacing plugs used in various reactors, proposal of a simplified method for manufacturing an end plug, improvements in mechanical and thermophysical properties of end plugs.

The end plug includes two parts in the form of coaxial cylinders having different diameters, the diameter of the part configured to be arranged inside the cladding is less than the cladding inner diameter by 0.06-0.08 and 2-3 mm, respectively, for interposing brazes of different types. An end plug according to the third variant is composed of three parts in the form of three successively arranged coaxial cylinders having different diameters, the diameter of the two parts configured to be arranged inside the cladding being less than the cladding inner diameter by 0.06-0.08 and 2-3 mm, respectively, for interposing brazes of two types simultaneously. The effects of the invention are safety for the environment, possibility of using the developed end plugs as an alternative for replacing plugs used in various reactors, proposal of a simplified method for manufacturing an end plug, improvements in mechanical and thermophysical properties of end plugs.

A nuclear fuel assembly bottom end part debris filter has an inlet face (18A) and an outlet face (18B) opposed to the inlet face (18A) and comprises a plurality of filtering structures (50) protruding on the inlet face (18A) of the debris filter (18). Each filtering structure (50) has a structure base (52) and a structure apex (54) spaced along a structure axis (A), and each filtering structure (50) includes blades (56) distributed circumferentially around the structure axis (A). Each blade has one end connected to the structure base (52) and one end connected to the structure apex (54), and each blade (56) delimits a slot (58) with each adjacent blade (56) of the same filtering structure (50).

A nuclear fuel assembly bottom end part debris filter has an inlet face (18A) and an outlet face (18B) opposed to the inlet face (18A) and comprises a plurality of filtering structures (50) protruding on the inlet face (18A) of the debris filter (18). Each filtering structure (50) has a structure base (52) and a structure apex (54) spaced along a structure axis (A), and each filtering structure (50) includes blades (56) distributed circumferentially around the structure axis (A). Each blade has one end connected to the structure base (52) and one end connected to the structure apex (54), and each blade (56) delimits a slot (58) with each adjacent blade (56) of the same filtering structure (50).

A system for removing particulates of a fissile material includes first and second filtration paths. A first filter and a first valve are disposed in the first filtration path. A second filter and a second valve are disposed in the second filtration path. The first valve and the second valve are configured to switch between a dual open state and a mixed open/closed state. During the dual open state, the first valve and the second valve axe open to permit concurrent flows of the effluent gas through the first and second filtration paths. During the mixed open/closed state, one of the first valve and the second valve is open while the other of the first valve and the second valve is closed to permit the particulates on a corresponding one of the first filter and the second filter to be dislodged by a countercurrent flow of a purging gas.

A method for peening an obstructed region of a metal assembly that is obstructed by an obstructing part of the metal assembly is provided. The method includes determining an optimal peening path for treating the obstructed region irrespective of the obstructing part; identifying a portion of the obstructing part within the optimal peening path; determining a section of the portion of the obstructing part that is removable without affecting a mechanical integrity and functionality of the obstructing part; removing, by machining, the section so as to create additional space along the optimal peening path; and peening the obstructed region, a path of the peening at least partially crossing through the additional space. A method for peening a nuclear reactor pressure vessel is also provided.

A method for peening an obstructed region of a metal assembly that is obstructed by an obstructing part of the metal assembly is provided. The method includes determining an optimal peening path for treating the obstructed region irrespective of the obstructing part; identifying a portion of the obstructing part within the optimal peening path; determining a section of the portion of the obstructing part that is removable without affecting a mechanical integrity and functionality of the obstructing part; removing, by machining, the section so as to create additional space along the optimal peening path; and peening the obstructed region, a path of the peening at least partially crossing through the additional space. A method for peening a nuclear reactor pressure vessel is also provided.