Abrégé

A pressurized water reactor (PWR) comprises: a nuclear core comprising a fissile material; a cylindrical pressure vessel having a vertically oriented cylinder axis and containing the nuclear core immersed in primary coolant water; and a hollow cylindrical central riser disposed concentrically with and inside the cylindrical pressure vessel. A downcomer annulus is defined between the hollow cylindrical central riser and the cylindrical pressure vessel. The hollow cylindrical central riser has a radially expanding upper orifice that merges into an annular divider plate that separates an upper plenum above the annular divider plate from a lower plenum below the annular divider plate. The upper plenum is in fluid communication with the radially expanding upper orifice and the lower plenum is in fluid communication with the downcomer annulus. A weir may extend away from a bottom wall of the lower plenum into the lower plenum.

Classes IPC  ?

• G21C 15/18 - Dispositions pour le refroidissement d'urgenceMise hors circuit de la chaleur

Abrégé

A pressurized water reactor (PWR) includes a pressure vessel and a nuclear reactor core disposed in the pressure vessel. A baffle plate is disposed in the pressure vessel and separates the pressure vessel into an internal pressurizer volume disposed above the baffle plate and an operational PWR volume disposed below the baffle plate. The baffle plate comprises first and second spaced apart plates, and includes a pressure transfer passage having a lower end in fluid communication with the operational PWR volume and an upper end in fluid communication with the internal pressurizer volume at a level below an operational pressurizer liquid level range. A vent pipe has a lower end in fluid communication with the operational PWR volume and an upper end in fluid communication with the internal pressurizer volume at a level above the operational pressurizer liquid level range.

Classes IPC  ?

• G21C 1/09 - Dispositions pour la régulation de pression, c.-à-d. pressuriseurs

Abrégé

In an illustrative embodiment, a pressurized water nuclear reactor (PWR) includes a pressure vessel (12, 14, 16), a nuclear reactor core (10) disposed in the pressure vessel, and a vertically oriented hollow central riser (36) disposed above the nuclear reactor core inside the pressure vessel. A once-through steam generator (OTSG) (30) disposed in the pressure vessel includes vertical tubes (32) arranged in an annular volume defined by the central riser and the pressure vessel. The OTSG further includes a fluid flow volume surrounding the vertical tubes and having a feedwater inlet (50) and a steam outlet (52). The PWR has an operating state in which feedwater injected into the fluid flow volume at the feedwater inlet is converted to steam by heat emanating from primary coolant flowing inside the tubes of the OTSG, and the steam is discharged from the fluid flow volume at the steam outlet.

Classes IPC  ?

• G21C 19/28 - Dispositions pour introduire un matériau fluent à l'intérieur du cœur du réacteurDispositions pour enlever un matériau fluent du cœur du réacteur

Abrégé

A radioactive debris trap to be installed in a steam generator for removing debris in the primary flow of a nuclear power plant's primary heat transport system. The debris trap includes an outer cylinder and a coaxial inner cylinder both having a top end and a bottom end. A top plate connects the top ends of the outer and inner cylinders. A bottom plate which encloses the trap is connected to the bottom end of the outer cylinder. There is a gap between the bottom end of the inner cylinder and the bottom plate through which primary flow enters a settling chamber located in an annular gap between the outer and inner cylinders. Several small holes are located at the top end of the outer cylinder through which liquid exits the debris trap. A means for fixedly connecting the debris trap to the steam generator is provided on the outer surface of the outer cylinder. Also included is a means for removing the radioactive debris trap from the steam generator without exposing personnel to excessive radiation.

Classes IPC  ?

• G21C 19/307 - Dispositions pour introduire un matériau fluent à l'intérieur du cœur du réacteurDispositions pour enlever un matériau fluent du cœur du réacteur avec purification continue du matériau fluent en circulation, p. ex. par extraction des produits de fission spécialement adaptés pour des liquides
• B01D 35/027 - Filtres adaptés à des endroits particuliers, p. ex. conduites, pompes, robinets montés de façon rigide dans ou sur des récipients ou des réservoirs
• B01D 35/16 - Dispositifs de nettoyage
• B01D 35/30 - Structure du carter de filtre

Abrégé

The invention is related to an improved method of removing tubes from tubes sheets. The improved method softens and elongates a tube circumferentially surround by tube sheet, wherein the softening and elongating steps allow for quick and easy removal of the tube from the tube sheet without damaging the tube sheet or tube seats.

Classes IPC  ?

• B23P 6/00 - Remise en état ou réparation des objets

Abrégé

A gravity feed, natural circulation boiler for an SAGD process using low quality feedwater for carbonatious material recovery, has a large diameter steam drum with downcomers. A furnace of the boiler has individually replaceable membrane wall modules, each with upper and lower headers and membrane roof, wall and floor parts connected to the drum and defining a fire box having an inlet end and an outlet end. The furnace includes a membrane front wall connected to the drum with a windbox upstream of the front wall. Burners at the inlet end of the firebox heat the firebox and riser pipes are connected between the steam drum and the upper header for supplying steam to the steam drum when the firebox in heated, the downcomer pipes being connected to the lower header for supplying water from the stream drum under gravity feed so that each module defines a single circuit. Furnace outlet screen bank and subsequent generating banks each with upper and lower headers and associated feeder and riser tubes complete the boiler.

Classes IPC  ?

• F22G 7/14 - Surchauffeurs de vapeur caractérisés par leur emplacement ou leur disposition dans les chaudières à tubes d'eau, p. ex. entre les batteries de tubes d'eau
• F22B 25/00 - Chaudières à faisceaux de tubes d'eau avec tubes de fumées passant à l'intérieur de ces tubes