Abstract: A plant operation apparatus for satisfying a separation criteria includes an operation panel, an operation display screen control device for controlling a display on the operation panel and a touch operation and for selecting a train in a software selection function based on the operation signal from the operation panel, a selection device having momentary push buttons and for resetting other push buttons in a hardware train selection function when an operator pushes one of the push buttons to select a train, and for outputting a control signal to select the train corresponding to the button pushed by the operator. The plant operation apparatus realizes the train selection system having multiplicity, diversity, and independence for satisfying the separation criteria.

Abstract: A nuclear reactor includes a core melt collection chamber having walls with multilevel protective layers. The layers include one layer part made of refractory concrete and another layer part made of ceramic bricks. The protective layers are anchored to the structural concrete of the collection chamber. In order to provide structural simplification, the layer part made of refractory concrete is constructed in the form of prefabricated blocks which are jointed together and are fastened to the structural concrete, and the layer part made of ceramic bricks is braced to the blocks of the layer part made of refractory concrete.

Abstract: A power range monitor apparatus includes a plurality of average power range monitors for calculating/monitoring local power values, average reactor power values, and core flow rate values, a plurality of rod block monitors for monitoring the average values of local power values, and a plurality of flow rate signal converters for converting the signal form of recirculation rate detection signals. The flow rate signal converters concurrently transmit recirculation rate detection signals as digital signals to the average power range monitors. The average power range monitors obtain core flow rate signals from the respective recirculation rate detection signals, use them to monitor the average reactor power, and transmit them to the rod block monitors. The rod block monitors select optimal values from average reactor power values and core flow rate signals to perform a monitoring operation.

Abstract: A neutron delivery system that provides improved capability for tumor control during medical therapy. The system creates a unique neutron beam that has a bimodal or multi-modal energy spectrum. This unique neutron beam can be used for fast-neutron therapy, boron neutron capture therapy (BNCT), or both. The invention includes both an apparatus and a method for accomplishing the purposes of the invention.

Abstract: A nuclear fuel identification system for use in nuclear power plants has an imaging system having a video camera and an array of illuminators surrounding the video camera and positioned to shine onto a nuclear fuel cell. The illuminators are sequentially activated to provide a series of images each having a different shadow pattern. These images are then digitized and stored until a complete set of the images are available. At that time, the images are superimposed and optimized for improved contrast. By viewing the distinct shadow patterns on the nuclear fuel cell, the identifying markings are readily visible. In addition to the shadow imaging system, a variety of laser devices are used to accomplish similar image generating functions. Such laser devices include a laser scanner, a distance laser device, an interferometer, a holographic interferometer, and a bi-refringent crystal prism.

Abstract: Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening.

Abstract: A fuel assembly locator for guiding and inserting nuclear fuel assemblies into a grid plate of a reactor vessel during reload. In the preferred embodiment, the fuel assembly locator includes a plurality of generally trapezoidal guides each having a multiplicity of serially increasing tiered slope regions for gradually directing the fuel assembly precisely into a grid plate opening. The increasing slope regions allow greater positional tolerance between the exterior of the fuel assembly and the interior opening of the grid plate opening initially, thus requiring less time and precision to align the fuel assembly with respect to the grid plate opening. The tolerance then gradually decreases since the slope of each successive tier is greater than the previous tier, thus precisely directing the fuel assembly into alignment with the grid plate opening for insertion therein.

Abstract: Apparatus suitable for transporting and storing nuclear fuel rods comprising a basket having storage cells formed from a honeycomb gridwork of metal plates in a rectilinear configuration, the plates welded to each other at their intersections so that all contiguous corners of the storage cells formed by the gridwork are completely connected so as to allow conduction heat transfer, the metal plates having neutron absorber material positioned in areas which form walls of the storage cells.

Abstract: An electrochemical corrosion potential sensor is fabricated by initially joining an electrical conductor to a sensor tip. An electrical cable is joined to the tip conductor. Ceramic powder is fused under heat around the tip conductor to form an integral annular electrically insulating band therearound to insulate the tip from the cable. The band may be formed by plasma spraying, or it may be molded and sintered to seal it to the tip and conductor without brazing. In a preferred embodiment, the band is formed of yttria-stabilized-zirconia or magnesia-stabilized-zirconia.

Abstract: Systems, methods, and apparatus for preventing steam leakage between a drywell and a wetwell in a nuclear reactor are described. In accordance with one embodiment of the present invention, the vacuum breaker of the nuclear reactor is coupled to a vacuum breaker condensing system which includes a condenser and a steam inlet pipe. The steam inlet pipe is substantially hollow and includes a first end, a second end, and a loop seal between the first and second ends. The first end of the pipe is positioned adjacent the drywell and the second end of the pipe is coupled to the vacuum breaker. The condenser is positioned proximate the steam inlet pipe and includes an inlet, an outlet, and a plurality of condenser tubes. The condenser inlet and condenser outlet are each coupled to a pool of water, e.g., the Gravity Driven Cooling System pool, and configured to draw water from the pool of water and through the condenser tubes to substantially condense steam flowing through the steam inlet pipe.

Abstract: A combination torpedo tube test plug and muzzle door for a torpedo tube iudes a circumferential land formed at an extreme muzzle end of the torpedo tube. The circumferential land has an inner peripheral diameter less than an inner peripheral diameter of the torpedo tube, and an inner peripheral transition surface contiguously joining the inner peripheral surface of the torpedo tube. An abutting face is formed on an end of the muzzle door facing the circumferential land. A lip extension extends from the abutting face. The lip extension includes an outer peripheral surface mating with the inner peripheral surface of the circumferential land, and a device for selectively securing the lip extension to the inner peripheral surface of the circumferential land, wherein separation of the muzzle door from the torpedo tube is prevented.

Abstract: From opposed ends of a front frame, there extend right and left side frames. A front suspension structure is arranged behind the front frame and located between the right and left side frames. The front suspension structure includes a front member which extends between respective lower portions of the right and left side frames. The front member has a steering gear mounted thereon. A reinforcing structure extends between the front frame and the front member to reinforce the front suspension structure against an external force suddenly applied to the front member.

Abstract: A cask for a radioactive material has a single gamma ray and neutron shielding layer disposed on the outside of a vessel body, and the shielding layer is formed of the compact of a mixture of lead and a metal hydride dispersed therein. This cask can exhibit an excellent shielding effect according to the balance of radiation source intensity between gamma rays and neutrons, and can be made more compact.

Abstract: An automated system for identifying nuclear power plant components includes a camera which provides an input signal from an image of the nuclear power plant components. A digitizer generates a digitized image of the nuclear power plant components from the input signal. A workstation locator routine locates the component identifier of the nuclear power plant components from pixel elements of the digitized image and a workstation determining routine determines the component identifier. The determining routine includes plural recognizer routines each having an output providing an intermediate recognition of the component identifier, and a combining routine combining the outputs of the recognizer routines to recognize the component identifier. Each of the outputs includes an intermediate identifier and a corresponding confidence value.

Abstract: A combined tactical breaching device and flash suppressor comprising a cylindrical body portion having a longitudinal central smoothbore, the body portion being threaded at one end thereof for threadedly engaging the muzzle of a firearm barrel, a pair of longitudinally extending diametrically opposed furcations formed in the other end of the body portion by a pair of diametrically opposed slots formed in the body portion and extending from the other end toward the first end, the slots being of a length and width such that when the other end is placed against a target and in contact therewith, frangible ammunition may be discharged through said device for breaching the target; also disclosed is a method for breeching a barrier such as a door, dead bolt locks and 1/4 inch steel plate, where applicable.

Abstract: A rack for storing or transporting nuclear fuel assemblies includes a plurality of adjacent prismatic cells having cell walls defining interior fuel assembly storage spaces. The cell walls are formed from a criss-crossed, ordered stack of elongated structural elements of constant cross section, disposed in successive layers and having a long dimension perpendicular to the axis of the cells. Neutrophage sections in tubular form and having a cross section corresponding to that of the cells are disposed against the cell walls within the nuclear fuel assembly storage spaces.

Abstract: A swirler is releasably attached to a spacer and lies in the opening through the spacer lying above a part-length fuel rod in a nuclear fuel bundle. Adjacent ferrules have upstanding tabs with loops forming part of connecting elements for releasably securing the swirler to the spacer. The spacer is mounted on a mounting ring having radially outwardly directed elements terminating in barbed ends for insertion through the loops in response to rotation of the swirler mounting ring relative to the tabs. The barbed ends can be squeezed together to release the swirler from its attachment with the spacer.

Abstract: A particle accelerator (12) generates an input particle beam having an initial energy level above a threshold for generating secondary nuclear particles. A thin target (14) is rotated in the path of the input beam for undergoing nuclear reactions to generate the secondary particles and correspondingly decrease energy of the input beam to about the threshold. The target (14) produces low energy secondary particles and is effectively cooled by radiation and conduction. A neutron scatterer (44) and a neutron filter (42) are also used for preferentially degrading the secondary particles into a lower energy range if desired.

Abstract: A coolant pipe blocking device for use in a nuclear power plant is provided to temporarily choke up a coolant inlet pipe to thereby inhibit fluid communication between a reactor and a steam generator, the steam generator having a coolant chamber in communication with the reactor via the coolant inlet pipe and a manway providing access to the coolant chamber. The pipe blocking device includes a plurality of hub segments(42-48) arranged along a longitudinal axis substantially with a uniform spacing to one another and an elongated, flexible, support rod(50) extending in a coaxial relationship with the longitudinal axis for interconnecting and keeping spaced apart the hub segments. A plurality of bladders(52-60) are arranged in an end-to-end relationship with respect to one another and attached to the hub segments to define a series of hermetically sealed air chambers.

Abstract: A nuclear fuel assembly for use in a pressurized water reactor comprising a top nozzle and a bottom nozzle, fuel rods loaded and supported by grids in cells thereof and interconnected between a lowermost grid and the top nozzle, and a filter member interposed between the lowermost grid and the bottom nozzle.