A method for producing microencapsulated fuel pebble fuel more rapidly and with a matrix that engenders added safety attributes. The method includes coating fuel particles with ceramic powder; placing the coated fuel particles in a first die; applying a first current and a first pressure to the first die so as to form a fuel pebble by direct current sintering. The method may further include removing the fuel pebble from the first die and placing the fuel pebble within a bed of non-fueled matrix ceramic in a second die; and applying a second current and a second pressure to the second die so as to form a composite fuel pebble.

A nuclear fuel storage cask includes an outer shell having a length extending from a first end to a second end of the outer shell, the outer shell defining an inner cavity circumscribed by the outer shell, an outer perimeter extending around the outer shell, an inner perimeter positioned inward from the outer perimeter, and a cooling circuit extending along the length of the outer shell, the cooling circuit including an inner passage, and an outer passage, a coolant positioned within the cooling circuit, where the coolant is configured to move through the inner passage, absorbing heat from the inner cavity of the outer shell, and the coolant is configured to move through the outer passage, dissipating heat through the outer perimeter of the outer shell, and a lid coupled the outer shell, where the lid covers the inner cavity of the outer shell.

A nuclear reactor includes guide tubes; and vessel head penetrations each comprising a tubular adapter fixed in one of the openings and defining an inner passage. Each vessel head penetration also includes a tubular sleeve engaged in the inner passage and axially extending in line with one of the guide tubes. Each sleeve is suspended by an upper axial sleeve end lying on an upper range on the corresponding adapter. A lower axial end of the sleeve projects axially into the vessel beyond the adapter and is separated from an upper axial end of the corresponding guide tube by an axial gap having an axial height of less than 50 millimeters.

The present disclosure discloses a Single-Event Transient (SET) pulse measuring circuit capable of eliminating impact thereof, and an integrated circuit chip. The SET pulse measuring circuit capable of eliminating impact thereof includes four parts: a SET pulse test chain, a latch circuit, a flip-flop test circuit, a latching self-trigger circuit. The integrated circuit chip is provided with a test chain module and two sets of SET pulse measuring circuits capable of eliminating impact thereof, and inputs of the two sets of SET pulse measuring circuits capable of eliminating impact thereof are the same and each are connected to an output terminal of the test chain module.

The present disclosure belongs to the field of materials with metal structures, and specifically relates to a preparation method for a nano-oxide dispersion strengthened steel. The method includes mixing a ferrochromium alloy, a ferrotungsten alloy, a ferroalloy containing a rare earth element, an oxygen source and a reduced iron powder to obtain a mixture; wrapping the mixture in a steel strip, and conducting drawing reducing to obtain a flux-cored wire; and conducting arc additive manufacturing on the flux-cored wire on a substrate, and then conducting heat treatment to obtain the nano-oxide particle dispersion strengthened steel.

An improved retention system for retaining fuel rods in a fuel assembly is disclosed. The retention system includes a plurality of first engagement surfaces on the bottom nozzle of a fuel assembly. There is at least one engagement surface for each fuel rod. A second engagement surface is formed on the bottom end plug of each fuel rod. The first and second engagement surfaces are configured for engagement with each other for axially and laterally retaining each fuel rod within the fuel assembly. Debris deflectors may also be provided to deflect debris from coolant channels surrounding the fuel rods.

A pit gate includes a gate body which is inserted between a pool portion storing water and a canal portion connected to the pool portion and is configured to change a flow state of the water, and a seal portion (6) which is accommodated in a groove-shaped accommodation recess formed in the gate body and seals between the pool portion and the gate body. The seal portion (6) includes a low-rigidity portion (10) which is relatively easily deformed by a load according to a water pressure from the pool portion side, and a high-rigidity portion (11) which is provided on the pool portion side of the low-rigidity portion and is not easily deformed relatively by the load.

A method for restraining a sleeve lining a tube passing through a nuclear reactor pressure vessel is provided. The method includes attaching in situ a radial protrusion on an external surface of the sleeve; and attaching a collar to an end of the tube and coupling the radial protrusion with the collar to retain the thermal sleeve in position.

Apparatus and methods for jet impingement cooling are provided. In one arrangement, a fluid channelling structure engages against a target surface to define a flow volume. Fluid is jetted onto the target surface from inlets and is removed via outlets. Flow directing features form a plurality of channels with no straight paths between inlets and outlets. A time averaged flow direction of fluid in contact with each flow directing feature is more nearly perpendicular to a direction of jetting of the fluid from a nearest inlet than parallel to the direction of jetting One or more pairs of the inlets and outlets are such that a majority of fluid jetted onto the target surface from the inlet of the pair will be removed from the flow volume through the outlet of the same pair.

Methods for forming particulates that are highly consistent with regard to shape, size, and content are described. Particulates are suitable for use as reference materials. Methods can incorporate actinides and/or lanthanides, e.g., uranium, and can be used for forming certified reference materials for use in the nuclear industry. Methods include formation of an aerosol from an oxalate salt solution, in-line diagnostics, and collection of particles of the aerosol either in a liquid impinger or on a solid surface.