Abstract: A control rod drive mechanism (CRDM) includes a lifting rod supporting a control rod and a holding mechanism comprising an electromagnetic circuit with magnetic poles drawn together when the electromagnetic circuit is energized to hold the lifting rod. The hold is released upon de-energizing the electromagnetic circuit. A translation mechanism linearly translates the lifting rod held by the holding mechanism. The holding mechanism may include a non-magnetic spacer between the magnetic poles that defines a gap between the drawn together magnetic poles. The translation mechanism may include latches configured to engage an upper end of the lifting rod, and the holding mechanism draws the magnetic poles together to hold the latches engaged with the upper end of the lifting rod. A four-bar cam assembly may be used to cam the latches closed in response to a vertical actuation force applied to the cam bars.

Abstract: A nuclear reactor includes a pressure vessel and a nuclear reactor core disposed in the pressure vessel. A subterranean containment structure contains the nuclear reactor. An ultimate heat sink (UHS) pool is disposed at grade level, and an upper portion of the subterranean containment structure defines at least a portion of the bottom of the UHS pool. In some embodiments, the upper portion of the subterranean containment structure comprises an upper dome, which may protrude above the surface of the UHS pool to define an island surrounded by the UHS pool. In some embodiments, a condenser comprising a heat exchanger including hot and cold flow paths is disposed inside the subterranean containment structure; and cooling water lines operatively connect the condenser with the UHS pool.

Abstract: A control rod drive mechanism (CRDM) configured to latch onto the lifting rod of a control rod assembly and including separate latch engagement and latch holding mechanisms. A CRDM configured to latch onto the lifting rod of a control rod assembly and including a four-bar linkage closing the latch, wherein the four-bar linkage biases the latch closed under force of gravity.

Abstract: Exemplary methods and apparatuses are provided that address how to turn visitor location register location data from telecommunications networks into information that can be aggregated across network switches, accessed by a direct query mechanism or via application programming interfaces, and reported upon from a single point of entry without affecting the performance or capacity of the network switches. Specifically, a Location Aggregation Server is provided that is configured to aggregate mobile terminal location data across multiple visitor location registers and to populate a database with the location information, e.g., an identifier of the mobile terminal and an identifier of a new location of the mobile terminal. Service providers and third parties may be able to search the database, display mobile terminal location data on a map, or aggregate the mobile terminal location data into meaningful statistics.

Abstract: Disclosed are compounds of the formulae wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, and R13 are hydrogen, alkyl, aryl, arylalkyl, or alkylaryl, R10, R11, and R12 are alkylene, arylene, arylalkylene, or alkylarylene, and the chromogen moiety is an atom or group of atoms that impart color to the compound in the visible, infrared, or ultraviolet wavelength range.

Abstract: A control rod drive mechanism (CRDM) configured to latch onto the lifting rod of a control rod assembly and including separate latch engagement and latch holding mechanisms. A CRDM configured to latch onto the lifting rod of a control rod assembly and including a four-bar linkage closing the latch, wherein the four-bar linkage biases the latch closed under force of gravity.

Abstract: 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.

Abstract: A nuclear reactor comprises a pressure vessel, a nuclear reactor core comprising fissile material disposed in the pressure vessel, and a core basket disposed in the pressure vessel and containing the nuclear reactor core. An incore instrument is disposed in a guide tube of the nuclear reactor core. The incore instrument has a cable extending out of the bottom of the nuclear reactor core and making a 180° turn. A bottom support element is attached to the bottom of the core basket and defines or includes a routing tube that routes the cable of the incore instrument through the 180° turn. In some embodiments, the pressure vessel includes upper and lower vessel portions, the nuclear reactor core and core basket are disposed in the lower vessel portion, and the vessel penetration is through the lower vessel portion or through a mid-flange connecting the upper and lower vessel portions.

Abstract: A nuclear reactor core comprising fissile material is surrounded by a core former. The core former comprises one or more single-piece annular rings wherein each single-piece annular ring comprises neutron-reflecting material. In some embodiments the core former comprises a stack of two or more such single-piece annular rings. In some embodiments the stack of single-piece annular rings is self-supporting. In some embodiments the stack of single-piece annular rings does not include welds or fasteners securing adjacent single-piece annular rings together. A core basket may contain the nuclear reactor core and the core former, and in some embodiments an annular gap is defined between the core former and the core basket. In some embodiments the core former does not include welds and does not include fasteners.

Abstract: A nuclear reactor comprises a nuclear reactor core disposed in a pressure vessel. An isolation valve protects a penetration through the pressure vessel. The isolation valve comprises: a mounting flange connecting with a mating flange of the pressure vessel; a valve seat formed into the mounting flange; and a valve member movable between an open position and a closed position sealing against the valve seat. The valve member is disposed inside the mounting flange or inside the mating flange of the pressure vessel. A biasing member operatively connects to the valve member to bias the valve member towards the open position. The bias keeps the valve member in the open position except when a differential fluid pressure across the isolation valve and directed outward from the pressure vessel exceeds a threshold pressure.

Abstract: A valve for controlling flow of high pressure fluid to a CRDM hydraulic latching mechanism of a nuclear reactor core. The valve includes a valve body having an inlet for receiving fluid from a fluid source, an outlet, and a dump port for dumping fluid backflow. A valve member is movable within the valve body between a first position restricting flow between the outlet and the dump port such that high pressure fluid entering the valve body through the inlet exits the valve body through the outlet, and a second position whereat the dump port is in fluid communication with the outlet such that at least a portion of any backflow fluid flowing back into the valve body via the outlet exits the valve body via the dump port.

Abstract: Disclosed are compounds of the formulae wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, and R13 are hydrogen, alkyl, aryl, arylalkyl, or alkylaryl, R10, R11, and R12 are alkylene, arylene, arylalkylene, or alkylarylene, and the chromogen moiety is an atom or group of atoms that impart color to the compound in the visible, infrared, or ultraviolet wavelength range.

Abstract: 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.

Abstract: A nuclear reactor includes a pressure vessel and a nuclear reactor core disposed in the pressure vessel. A subterranean containment structure contains the nuclear reactor. An ultimate heat sink (UHS) pool is disposed at grade level, and an upper portion of the subterranean containment structure defines at least a portion of the bottom of the UHS pool. In some embodiments, the upper portion of the subterranean containment structure comprises an upper dome, which may protrude above the surface of the UHS pool to define an island surrounded by the UHS pool. In some embodiments, a condenser comprising a heat exchanger including hot and cold flow paths is disposed inside the subterranean containment structure; and cooling water lines operatively connect the condenser with the UHS pool.

Abstract: A pressurized water reactor (PWR) includes a vertical cylindrical pressure vessel and a nuclear reactor core disposed in a lower vessel section. A hollow cylindrical central riser is disposed concentrically inside the pressure vessel. A downcomer annulus is defined between the central riser and the pressure vessel. A reactor coolant pump (RCP) includes (i) an impeller disposed above the nuclear reactor core and in fluid communication with the downcomer annulus to impel primary coolant downward through the downcomer annulus, (ii) a pump motor disposed outside of the pressure vessel, and (iii) a drive shaft operatively connecting the pump motor with the impeller. The PWR may include an internal steam generator in the downcomer annulus, with the impeller is disposed below the steam generator. The impeller may be disposed in the downcomer annulus. The RCP may further comprise a pump casing that with the impeller defines a centrifugal pump.

Abstract: 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.

Abstract: A pressurized water reactor (PWR) includes a cylindrical pressure vessel defining a sealed volume, a nuclear reactor core disposed in a lower portion of the cylindrical pressure vessel, one or more control rod drive mechanisms (CRDMs) disposed in the cylindrical pressure vessel above the nuclear reactor core, and an annular steam generator surrounding the nuclear reactor core and the CRDM. In some such PWR, a cylindrical riser is disposed coaxially inside the pressure vessel and inside the annular steam generator and surrounds the nuclear reactor core and the CRDM, and the steam generator is disposed coaxially inside the cylindrical pressure vessel in an annular volume defined by the cylindrical pressure vessel and the cylindrical riser. In other such PWR, the steam generator is disposed coaxially outside of and secured with the cylindrical pressure vessel.

Abstract: A catheterization system for forming dual sutureless anastomoses using two catheters connectable to one another. Once the fistula is healed, a dissolvable connection allows the catheters to separate one from the other and the separated pieces are extruded through normal bowel action. The two catheters may be connected in various ways. In one embodiment, a separate guide member may be used to pull a dissolvable suture through the first catheter. The suture is then attached to the second catheter and the suture may be used to pull the second catheter into contact with the first catheter so that the two catheters are closely connected by the suture. When the suture dissolves, the two catheters separate. In another embodiment, the first catheter has a section formed of a dissolvable mesh. The two catheters may be connected together by any of various types of connections. After a period of time, the mesh dissolves and allows the joined catheters to separate into two pieces.

Abstract: A catheterization system for forming dual sutureless anastomoses using two catheters connectable to one another. Once the fistula is healed, a dissolvable connection allows the catheters to separate one from the other and the separated pieces are extruded through normal bowel action. The two catheters may be connected in various ways. In one embodiment, a separate guide member may be used to pull a dissolvable suture through the first catheter. The suture is then attached to the second catheter and the suture may be used to pull the second catheter into contact with the first catheter so that the two catheters are closely connected by the suture. When the suture dissolves, the two catheters separate. In another embodiment, the first catheter has a section formed of a dissolvable mesh. The two catheters may be connected together by any of various types of connections. After a period of time, the mesh dissolves and allows the joined catheters to separate into two pieces.