Abstract: A nuclear reactor in which the space between a reactor vessel and a guard vessel disposed outside the reactor vessel is kept in a pressurized, sealed state. The sealed space and the space outside the guard vessel are communicate only through a liquid manometer structure, which is kept sealed with liquid.

Abstract: A container has a massive metallic vessel whose interior is adapted to receive radioactive waste and whose mouth is formed with inner and outer spaced generally planar and annular vessel shoulders and formed therebetween with a nonplanar intermediate annular vessel surface. A massive metallic cover formed with a plug fits in the mouth and has respective inner and outer plug shoulders closely juxtaposed with the vessel shoulders and a nonplanar intermediate annular plug surface complementary to the intermediate vessel surface. An inner ring seal engages snugly between the inner shoulders. A pair of generally concentric and spaced outer ring seals engage snugly between the outer shoulders and forming an annular outer chamber therebetween. An intermediate ring seal engages snugly between the intermediate surfaces and forms therebetween and with the inner ring seal an annular inner chamber and therebetween and with the outer ring seals an intermediate chamber.

Abstract: A nuclear radiation actuated valve for a nuclear reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

Abstract: An ionizable material is ejected in the shape of a cylindrical column from a cathode-nozzle toward an anode and subjected to a very short, high voltage pulse of electrical current having sufficient magnitude to create a high magnetic field which implodes the cylindrical column of ionizable material to a very high density plasma that emits long wave length x-rays. Accurate and reliably reproduced x-ray bursts are provided through coupling of the cathode and anode to the high voltage pulse generator without substantially degrading the pulse. The conductors between the pulse generator and the cathode and anode are of a configuration whereby a magnetic field is used to prevent the electron losses by tapering the spacing between feed conductors and shaping the feed conductors so that space-charge flow is retrapped and made usable.

Abstract: The valve stem of the controlled shut-off valve has a lid and a piston movable in a cylinder. A first cylindrical chamber and a second annular chamber facing the lid are separated by a piston and connected to a low-pressure chamber by ducts extending in the housing of the shut-off valve and connecting lines connected to the ducts outside the housing. The first chamber is also connected to the inlet side of the shut-off valve via a duct extending in the housing and containing at least one control valve actuated by a control line. Closing valves are provided in the connecting lines. A throttle means having a fixed flow cross-section is disposed in the duct of the first chamber inside the housing. The duct of the second chamber has a fixed minimum cross-section.

Abstract: The invention provides an automatic channel box fitting position adjusting apparatus to facilitate positional adjustment of a channel box for fitting onto a nuclear fuel assembly. The apparatus comprises a position adjusting mechanism and a jig having a rod for controlling the position adjusting mechanism. The position adjusting mechanism includes guide rollers to guide the channel box to a correct fitting position. The guide rollers are tapered toward outer ends and are cantilevered at inner ends thereof.

Abstract: An apparatus is disclosed which measures forces resisting the movement of pistons in a control rod drive mechanism in a nuclear reactor and which includes pressure sensing means and further includes hydraulic circuitry to divert pressurized fluid from a normal operating conduit to a selected shunt conduit containing a valve having a particular fluid control characteristic, said shunt conduit directing the fluid to a selected piston to move said piston and said pressure sensing means measuring the pressure of the fluid during the motion of said piston to give an indication of the force needed to achieve such motion.

Abstract: A method and apparatus is shown for establishing a predetermined concentration of gas in the reactor core coolant for a pressurized water nuclear power system. Gas is added to core coolant water in a bubble column. The gas-water mixture flows through static mixers in the column to produce the desired gas concentration in the water.

Abstract: A device for deciphering encoded information is disclosed which comprises logic elements which combine a key input to implement a predetermined set of boolean transformations thereby yielding a corresponding set of translation terms. The translation terms are subsequently combined with corresponding encoded information to yield deciphered information.

Abstract: A control and power supply circuit is illustrated in the preferred and illustrated embodiment for providing power to a pulsed neutron generator tube. The preferred and illustrated embodiment includes power supplies and control circuits for providing operative power to the pulsed neutron generator tube. The system monitors the voltages supplied to a downhole sonde utilizing a shut regulator circuit which, with the remainder of the control circuitry set forth, properly and in controlled sequence empowers the pulsed neutron generator tube. The tube is provided with power to switch on and such power is switched off in timed sequence to avoid damaging the tube in the event of a malfunction or loss of power from the surface located power source for the sonde.

Abstract: A method of cooling the primary circuit of a pressurized water nuclear reactor in which, after a first stage, during which water is injected into the steam generators and the steam produced is discharged, cooling is continued during a second stage by water-water heat exchange. In this second stage, the water is made to circulate at the secondary side of at least one steam generator (2) in countercurrent to the primary water, over at least part of its path. The secondary water heated by the primary water is cooled outside the containment enclosure (1) of the nuclear reactor in at least one heat exchanger (31) using raw cooling water. The secondary water is recycled in the steam generator (2). The invention is applicable to the effecting an maintaining of cold shutdown of pressurized water nuclear reactors.

Abstract: A moisture separator reheater having a central chamber with cylindrical wall portions and a generally round tube bundle, the tube bundle having arcuate plates disposed on each side of the bundle which form a wrapper on each side of the tube bundle and having a tongue and groove juncture between the wrapper and cylindrical wall portions to provide a seal therebetween and a track for installing and removing the tube bundle from the central chamber.

Abstract: A manipulator for transferring fuel assemblies between inclined fuel chutes for a liquid metal nuclear reactor.Hoisting means are mounted on a mount supported by beams rotatably attached by pins to the mount and to the floor. Rotation of the beams can be impelled by a one dimensional movement causing the manipulator to accomplish a complicated, two dimensional transfer.

Abstract: In a secure communications system, a key number which is changed periodically, e.g. monthly, and a random number from a random number generator are combined and used as a seed to reset a PN sequence generator, with the output of the generator being used to control encryption of transmission data in a signal processor. The key is also provided to a first encipherer to encipher the random number for transmission with the encrypted data. At the receiver, the key is provided on common to a decipherer for deciphering the random number and a PN sequence generator which is periodically reset by the combination of the key and random number in the same manner as in the transmitter. The PN sequence is then used to decrypt the information. User identification codes are stored in the transmitter and are used to encipher the key, with each employing its ID code to decipher the key. The user ID codes are known only to the system operator, so that not even a particular user can know the key.

Abstract: A neutron/gamma ray technique for mapping the distribution of contaminants in an extended medium such as the wall (10) of a building. A neutron excitation source (14) is located on one side of the wall (10) and a gamma ray spectrometer, including a gamma ray detector (16), is located on the opposite side of the wall (10) facing the excitation source (12). The source and detector are moved in unison in discrete steps over opposing wall surfaces (12, 18) so as to determine the chemical composition of the elements in a hemispheric region (20) of the wall adjacent the detector with the radius of the region being substantially that of the mean free path distance of gamma rays emitted from elements interacting with neutrons on the detector side of the wall. The source (14) and detector (16) are reversed for relatively thick walls for mapping the distribution of elements on the other side of the wall thickness.

Abstract: A system and method for transmitting enciphered data between first and second terminals over a data transmission channel. The system comprises a transmitter located at the first terminal, a receiver located at the second terminal and cipher computers located at each of the first and second terminals. At least one of the cipher computers is programmable and has a program memory. Storage means are provided for storing a program code or algorithm and a secret cipher key, and means are further provided for transmitting the algorithm to the programmable computer for storage in its program memory. The data transmitted between the first and second terminals is enciphered in accordance with the algorithm stored in the program memory of the programmable computer and determined by the secret cipher key.

Abstract: Reactivity control assembly for nuclear reactor comprises supports stacked above reactor core for holding control rods. Couplers associated with the supports and a vertically movable drive shaft have lugs at their lower ends for engagement with the supports.

Abstract: A pressure vessel for a nuclear reactor comprises a reinforced concrete vessel with at least one open area located in the wall of the concrete vessel, a lining means anchored on the inside surface of the concrete vessel and the opea area for protection of the surfaces and at least one expansion space in the concrete vessel immediately adjacent the lining means to permit movement of the lining means and distribution of the stresses in the lining means under various reactor conditions.

Abstract: Gas-cooled high temperature reactor asembly, including a safety container, a chamber disposed in the safety container, a reactor vessel disposed in the chamber for receiving a charge of spherical fuel elements at a given location therein, the reactor vessel being formed of blocks of at least one material from the group consisting of carbon and graphite, a steel shell surrounding the reactor vessel, a metallic base plate supporting the reactor vessel, the base plate having openings formed therein for passing cooling gas blown in the chamber into the given location for a fuel element charge, at least one downwardly extended pipeline having a connection to the base plate for discharging heated gases, the connection being detachable by axial motion of the reactor vessel, a removable cover disposed on top of the chamber, and means disposed on the reactor vessel for connecting the reactor vessel to hoisting apparatus.

Abstract: Reactor building comprising internal structures, whose stresses are independent of the deformations of the general floor and of the background effect due to the reference accident pressure, and process for producing the internal structures.This reactor building comprises a confinement enclosure (4), internal structures (14) constituted by a slab (22) peripherally locked against the frustum-shaped member (12) of confinement enclosure (4) and resting on the general floor (8) by a peripheral supporting ring (23), a compressible layer (32) being provided between the general floor (8) and slab (22).Application to the construction of the internal structures of a reactor building.