Patent application number | Description | Published |
20130028367 | PRESSURIZED WATER REACTOR WITH REACTOR COOLANT PUMPS OPERATING IN THE DOWNCOMER ANNULUS - 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. | 01-31-2013 |
20130108005 | PRESSURIZED WATER REACTOR WITH UPPER VESSEL SECTION PROVIDING BOTH PRESSURE AND FLOW CONTROL | 05-02-2013 |
20130121453 | PRESSURIZED WATER REACTOR WITH UPPER PLENUM INCLUDING CROSS-FLOW BLOCKING WEIR - 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. An emergency core cooling system (ECCS) return line nozzle may be arranged to inject water into the upper plenum. A pump support plate spans the inner diameter of the cylindrical pressure vessel and forms a portion of the pressure boundary of the cylindrical pressure vessel, and reactor coolant pumps (RCPs) are supported by the pump support plate. Alternatively, reactor coolant pumps (RCPs) are supported by an arcuate annular ledge formed in the upper portion of the cylindrical pressure vessel. | 05-16-2013 |
20130223580 | CONTROL ROD DRIVE MECHANISM (CRDM) MOUNTING SYSTEM FOR PRESSURIZED WATER REACTORS - A standoff supporting a control rod drive mechanism (CRDM) in a nuclear reactor is connected to a distribution plate which provides electrical power and hydraulics. The standoff has connectors that require no action to effectuate the electrical connection to the distribution plate other than placement of the standoff onto the distribution plate. This facilitates replacement of the CRDM. In addition to the connectors, the standoff has alignment features to ensure the CRDM is connected in the correct orientation. After placement, the standoff may be secured to the distribution plate by bolts or other fasteners. The distribution plate may be a single plate that contains the electrical and hydraulic lines and also is strong enough to provide support to the CRDMs or may comprise a stack of two or more plates. | 08-29-2013 |
20130272465 | POWER DISTRIBUTION PLATE FOR POWERING INTERNAL CONTROL ROD DRIVE MECHANISM (CRDM) UNITS - A power distribution plate (PDP) sits on top of a support plate. Control rod drive mechanism (CRDM) units are mounted on top of the PDP, but the PDP is incapable of supporting the weight of the CRDM units and instead transfers the load to a support plate. The PDP has receptacles which receive cable modules each including mineral insulated (MI) cables, the MI cables being connected with the CRDM units. The PDP may further include a set of hydraulic lines underlying the cable modules and connected with the CRDM units. The cable modules in their receptacles define conduits or raceways for their MI cables and for any underlying hydraulic lines. | 10-17-2013 |
20130279640 | INCORE INSTRUMENTATION CABLE ROUTING FOR PRESSURIZED WATER REACTOR - A pressure vessel includes upper and lower vessel sections joined by a flanged connection. A nuclear reactor core includes an array of fuel assemblies comprising fissile material. The nuclear reactor core is disposed in the lower vessel section. A side-entry vessel penetration is located at a side of the pressure vessel and passes through one of (i) a flange of the flanged connection and (ii) the lower vessel section. An incore instrument routing tube extends from the side-entry vessel penetration and enters the reactor core from above the reactor core. The incore instrument routing tube extends from the side-entry vessel penetration with a declination angle A | 10-24-2013 |
20130287158 | SUSPENDED UPPER INTERNALS WITH TIE ROD COUPLINGS FOR COMPACT NUCLEAR REACTOR - A suspended basket includes a plurality of plates, tie rods, and adjustable length threaded tie rod couplings connecting threaded ends of the tie rods with threaded features of the plates. Control rod drive mechanisms (CRDMs) with CRDM motors are mounted in the suspended basket, which is suspended in a pressure vessel above a nuclear reactor core to control insertion of control rods into the reactor core. In one embodiment each adjustable length threaded tie rod coupling is a turnbuckle coupling that includes a sleeve threaded onto the threaded end of the tie rod and onto the threaded feature of the plate, and the sleeve is rotatable to adjust the position of the tie rod respective to the plate. Guide frames may be mounted in the suspended basket between the CRDMs and the nuclear reactor core to guide portions of the control rods withdrawn from the nuclear reactor core. | 10-31-2013 |
20130287160 | RISER TRANSITION ELEMENT FOR COMPACT NUCLEAR REACTOR - A nuclear reactor core is disposed in a pressure vessel along with upper internals disposed in the pressure vessel above the reactor core. The upper internals include internal control rod drive mechanisms (CRDMs) mounted on a suspended support assembly. A hollow cylindrical central riser is disposed in the pressure vessel above the nuclear reactor core. A hollow cylindrical section is disposed in the pressure vessel below the hollow cylindrical central riser and surrounding the nuclear reactor core. A riser transition element connects with the hollow cylindrical central riser and the hollow cylindrical section to form a continuous hollow cylindrical flow separator. The suspended support assembly of the upper internals is suspended from the riser transition element. The pressure vessel may comprise upper and lower vessel sections connected by a mid-flange, with the riser transition element welded to the mid-flange by gussets extending outward and upward from the riser transition element to the mid-flange. | 10-31-2013 |
20130301774 | LATERAL SUPPORT FOR CONTROL ROD DRIVE MECHANISM - Control rod drive mechanisms (CRDMs) include CRDM motors, and a support assembly provides bottom support of the CRDMs and includes a lateral alignment plate with openings receiving upper portions of the CRDMs. The upper portions of the CRDMs include compliance features engaging the openings of the lateral alignment plate. The compliance features may comprise angled leaf springs that wedge into the openings of the lateral alignment plate. In some embodiments the upper portion of each CRDM includes straps securing one or more cables to the upper portion of the CRDM, and the angled leaf springs are cut into or welded onto ends of the straps. Some embodiments further include a pressure vessel and a nuclear reactor core comprising fissile material disposed the pressure vessel, and the CRDM is an internal CRDM disposed in the pressure vessel along with the support assembly. | 11-14-2013 |
20130301775 | CRDM INTERNAL ELECTRICAL CONNECTOR - An internal control rod drive mechanism (CRDM) including an electric motor is disposed in a nuclear reactor and further includes a support surface with sealed electrical connectors electrically connected with the electric motor power the motor. The internal CRDM is disposed on a support element secured inside the nuclear reactor. The support element includes sealed electrical connectors mating with the sealed electrical connectors on the support surface of the internal CRDM to power the electric motor. The sealed electrical connectors may be sealed glass, ceramic, or glass-ceramic connectors welded onto the ends of the MI cables extending from the motor. Springs, are disposed between the mating sealed electrical connectors of the support element and the support surface. A purge line is integrated with each mated connection. | 11-14-2013 |
20130301776 | INTEGRAL PRESSURIZED WATER REACTOR WITH COMPACT UPPER INTERNALS ASSEMBLY - An integral pressurized water reactor (PWR) comprises: a cylindrical pressure vessel including an upper vessel section and a lower vessel section joined by a mid-flange; a cylindrical central riser disposed concentrically inside the cylindrical pressure vessel and including an upper riser section disposed in the upper vessel section and a lower riser section disposed in the lower vessel section; steam generators disposed inside the cylindrical pressure vessel in the upper vessel section; a reactor core comprising fissile material disposed inside the cylindrical pressure vessel in the lower vessel section; and control rod drive mechanism (CRDM) units disposed inside the cylindrical pressure vessel above the reactor core and in the lower vessel section. There is no vertical overlap between the steam generators and the CRDM units. | 11-14-2013 |
20130301777 | ELECTRICAL FEEDTHROUGHS FOR NUCLEAR REACTOR - A nuclear reactor includes a nuclear reactor core comprising fissile material and a pressure vessel containing the nuclear reactor immersed in primary coolant water at an operating pressure. The pressure vessel has a vessel penetration passing through a wall of the pressure vessel. An electrical feedthrough seals the vessel penetration and has an outside electrical connector mounted at the pressure vessel. The outside electrical connector is at atmospheric pressure. The electrical feedthrough may include a flange disposed inside the pressure vessel and sealing against an inside surface of the wall of the pressure vessel. The outside electrical connector of the electrical feedthrough may be inset into the wall of the pressure vessel. | 11-14-2013 |
20130301778 | CRDM INTERNAL HYDRAULIC CONNECTOR - In a nuclear reactor, an internal control rod drive mechanism (CRDM) includes a motor and a hydraulically driven element connected by at least one hydraulic line with at least one hydraulic connector disposed on a mounting plate of the internal CRDM. A support element mounted in the nuclear reactor includes at least one hydraulic connector. The internal CRDM is supported on the support element by its mounting plate with each hydraulic connector of the internal CRDM mated with a corresponding hydraulic connector of the support element. The hydraulically driven element may be a piston controlling SCRAM, driven by coolant water, and the coolant water pressure in the at least one hydraulic line is higher than the coolant water pressure in the nuclear reactor. The mating of each hydraulic connector of the internal CRDM with a corresponding hydraulic connector of the support element may be a leaky mating that leaks coolant water into the pressure vessel. | 11-14-2013 |
20130301779 | SMALL MODULAR REACTOR REFUELING SEQUENCE - A nuclear reactor includes at least: a pressure vessel including an upper vessel section and a lower vessel section connected by a mid-flange and containing primary coolant; a nuclear reactor core disposed in the lower vessel section and immersed in the primary coolant; and upper internals suspended from the mid-flange of the pressure vessel. The upper internals include at least internal CRDMs immersed in the primary coolant and control rod guide frames. To refuel, the nuclear reactor is depressurized. The upper vessel section is disconnected and removed while leaving the mid-flange in place with the upper internals remaining suspended from the mid-flange. The mid-flange is then removed with the upper internals remaining suspended from the mid-flange. The fuel is replaced, the mid-flange is placed back onto the lower vessel section with the upper internals remaining suspended from the mid-flange, and the upper vessel section is placed back and re-connected. | 11-14-2013 |
20130301783 | RISER CONE APPARATUS TO PROVIDE COMPLIANCE BETWEEN REACTOR COMPONENTS AND MINIMIZE REACTOR COOLANT BIPASS FLOW - A riser cone has a lower end sized to engage a cylindrical lower riser section of a nuclear reactor and an upper end sized to engage a cylindrical upper riser section of the nuclear reactor. The riser cone defines a compression sealing ring that is compressed between the lower riser section and the upper riser section in the assembled nuclear reactor. In some embodiments the riser cone comprises: a lower element defining the lower end of the riser cone; an upper element defining the upper end of the riser cone; and a compliance spring compressed between the lower element and the upper element. In some embodiments the riser cone comprises a frustoconical compression sealing ring accommodating a reduced diameter of the upper riser section as compared with the diameter of the lower riser section. | 11-14-2013 |
20130301785 | SUSPENDED UPPER INTERNALS FOR COMPACT NUCLEAR REACTOR INCLUDING A MID-HANGER PLATE - A pressure vessel comprises an upper vessel section and a lower vessel section. A nuclear reactor core comprising fissile material is disposed the lower vessel section. Upper internals are disposed in the lower vessel section above the nuclear reactor core and are mounted on a suspended support assembly including a plurality of hanger plates connected by tie rods. The upper internals include at least guide frames and internal control rod drive mechanisms (CRDMs) with CRDM motors. The plurality of hanger plates includes a mid-hanger plate that is not the uppermost plate of the plurality of hanger plates and is not the lowermost plate of the plurality of hanger plates. The internal CRDMs are disposed above the mid-hanger plate, the guide frames are disposed below the mid-hanger plate, and the mid-hanger plate engages both the internal CRDMs and the guide frames. | 11-14-2013 |
20130301786 | SUSPENDED UPPER INTERNALS FOR COMPACT NUCLEAR REACTOR INCLUDING AN UPPER HANGER PLATE - A pressure vessel comprises an upper vessel section and a lower vessel section. A nuclear reactor core comprising fissile material is disposed in the lower vessel section. Upper internals are disposed in the lower vessel section above the nuclear reactor core. The upper internals include at least internal control rod drive mechanisms (CRDMs) with CRDM motors and a suspended support assembly with a plurality of hanger plates connected by tie rods. The internal CRDMs are supported from beneath by a first hanger plate and are laterally aligned by a second hanger plate disposed above the first hanger plate. | 11-14-2013 |