Abstract: A core cooling system for a nuclear reactor having a plurality of primary fluid flow systems. The reactor coolant flow from the primary systems is joined upon entering the pressure vessel. Jointure is accomplished in a common chamber causing high coolant flow velocities at low static pressures. If a pipe ruptures in one of the primary fluid flow systems, the low pressure in the common chamber minimizes leakage from the intact flow systems. This allows continuation of coolant flow through the nuclear core for a sufficient length of time to effectively eliminate the possibility of thermal damage.

Abstract: A snap action electrical switch is disclosed which includes an actuating plunger slidably mounted within a switch housing, which carries two pairs of circumferentially spaced terminals. The plunger carries two sets of contacts which correspond to respective pairs of the terminals. Each set of the contacts includes a pair of spheres slidingly mounted within a transverse bore provided within the plunger and a spring which yieldably urges the spheres toward opposite ends of the transverse bore. An insulating member is disposed between the terminals and the plungers. One pair of apertures, provided in the insulating member, register with one of the transverse bores when the plunger is in one position and another pair of apertures register with the other transverse bore when the plunger is moved to another position.

Abstract: The pressure vessel of a reactor such as a PWR is provided with nozzles for the emergency injection of coolant into at least one water-box placed above the reactor core and rigidly fixed to the pressure vessel. Sprinkler-tubes placed within the fuel assemblies in parallel relation to the fuel pins are each connected to the water-box by means of a rectilinear tube.

Abstract: The space formed between the primary vessel of a sodium-cooled fast reactor and a leak jacket surrounding the vessel is filled with an inert gas which is maintained at a pressure in the vicinity of atmospheric. A vacuum is created within the space formed between the leak jacket and the concrete reactor vault and means are provided for detecting the presence of inert gas within the evacuated space and thus continuously testing the jacket for leak-tightness and mechanical resistance.

Abstract: A plurality of light boxes adapted to be transported and stored in a knocked-down and disassembled condition to be readily assembled, set up and connected together, with a divider between adjacent light boxes and with a front translucent panel for each light box which is lit up by lights within each light box. Each translucent panel having a flange, with the flanges of the adjacent panels being held in abutting relationship by clamping means which eliminates mullions therebetween and with the clamping means so constructed to eliminate and/or reduce the shadows on the panels at such junctures. The adjacent panels presenting when lighted a continuous surface where the dividing lines between adjacent panels are substantially imperceptible.

Abstract: A method for removing cesium 137, iodine 131 and tritium from a liquid sodium reactor coolant. Hydrogen is introduced into the liquid sodium causing sodium hydride to precipitate in a cold trap. The cesium iodine and tritium isotopes are removed from the liquid sodium by coprecipitating as impurities in the sodium hydride.

Abstract: An apparatus for containing the components of a nuclear reactor core during a core-melt-down accident, comprising a container consisting at least its inner surface of a highly temperature resistant material.

Abstract: In a nuclear reactor, a line for supplying emergency coolant is connected directly to the reactor pressure vessel and equipped in the interior of the latter with an emergency coolant flow-directing device whose exit runs parallel to the wall of the pressure vessel in a direction toward the lower edge of the core. The invention provides, particularly in pressurized-water reactors, more rapid flooding of the reactor core in case of a loss-of-coolant accident.

Abstract: A cooler for a bottom tray of a liquid metal-cooled nuclear reactor, the tray serving as a receptacle for a melting reactor core in the event of a hypothetical accident, comprising coolant distribution and collecting pipes disposed below the bottom tray about the circumference thereof, and a plurality of parallel tubes connecting said distribution and collecting pipes, said tubes being in the shape of involutes running between the center and circumference of said tray.

Abstract: A display sign is disclosed for displaying printed matter on a backlighted poster or the like. The sign includes a display case defining a first compartment containing a light source, the display case having a front opening for the transmission of light therethrough. A closure panel is adapted to cover the front opening, the closure panel having a central transparent face panel. A concave translucent diffuser panel is located between the face panel and the light source so that the curvature of the concave diffuser panel extends toward the light source to define a second compartment between the diffuser panel and the face panel. VELCRO fastening means locate and retain the poster in the second compartment spaced between the closure panel and the concave diffuser panel. Vent openings communicate with the second compartment for the circulation of air around the poster.

Abstract: A system for reducing the possibility of leakage of fission gases from a nuclear reactor of the gas-cooled type or of a type utilizing a liquid coolant, for example a liquid metal with a cover gas above free surfaces of the coolant. The disclosed system reduces the leakage of fission gases from the cover gas through joints between a pressure vessel and a pressure vessel head in the nuclear reactor by installing an adsorbent material between two seals placed in the joints. This adsorbent material provides sufficient delay time to allow all radioactive isotopes, except long-lived nuclides, to decay to innocuous concentrations before escaping from the pressure vessel.

Abstract: A pressurized water nuclear reactor having a safety vessel containing a steam generator from which a live steam line extends, a shut-off and safety device includes valve means having a displaceable valve member connected in the live steam line within the safety vessel, and control piston means connected to the valve member for controlling opening and closing of the valve means, the control piston means comprising a control cylinder and a control member displaceable in the control cylinder and having a pair of opposite sides having working surfaces respectively subjectible to differences of pressure applied thereto in respective portions of the control cylinder located adjacent thereto for displacing the control member in respective directions so as to displace the valve member in corresponding directions to open and close the valve means, the portions of the control cylinder located adjacent the sides of the control member having means for effecting a pressure difference between the respective cylinder portio

Abstract: In a gas-cooled solid-moderated high-temperature reactor where fuel elements are introduced into the core through feed pipes in the ceiling reflector, the ceiling is cooled after reactor shutdown by introducing cooled gas through centrally arranged feed pipes and by removing the gas through the other feed pipes located radially outwardly of the inlet feed pipes. This arrangement effects a flow of the gas generally radially outwardly over the ceiling reflector. After the gas is removed from the core it is circulated through a closed circuit, cooled and blown back through the inlet feed pipes into the core.

Abstract: A rust retarder applicator which includes a tubular length to be inserted into the combustion chamber of an internal combustion engine when not in use, which is of a cross sectional area adapting the same for insertion through the spark plug opening and which includes a plug slidable therealong which is conical with its lower end being sized for receipt in the spark plug opening and its upper end being sized greater than the cross sectional area of the spark plug opening so that, when the plug is pressed into the spark plug opening, it will be closed, and the upper end of the tubular length including an adapter for connection to an aerosol spray can source of oily material to be sprayed into the combustion cylinder when the spark plug has been removed to weatherproof it.

Abstract: The intermediate heat transport system for a sodium-cooled fast breeder reactor includes a device for rapidly draining the sodium therefrom should a sodium-water reaction occur within the system. This device includes a rupturable member in a drain line in the system and means for cutting a large opening therein and for positively removing the sheared-out portion from the opening cut in the rupturable member. According to the preferred embodiment of the invention the rupturable member includes a solid head seated in the end of the drain line having a rim extending peripherally therearound, the rim being clamped against the end of the drain line by a clamp ring having an interior shearing edge, the bottom of the rupturable member being convex and extending into the drain line. Means are provided to draw the rupturable member away from the drain line against the shearing edge to clear the drain line for outflow of sodium therethrough.

Abstract: An emergency core cooling system for a nuclear reactor which preferably is supplemental to the main emergency core cooling system incorporated in the reactor at the time of construction. Under circumstances of a rupture in the reactor primary coolant piping and consequent drop in reactor coolant pressure, emergency supplemental coolant is supplied from tanks or accumulators through check valves into the head closure plenum area. From there, the coolant is distributed downwardly through hollow support columns and through control rod guide thimbles to the top of the fuel assemblies which comprise the reactor core. The pressure and flow of the emergency supplemental coolant is sufficiently great to overcome the normal upward flow of primary coolant through the core, the result being that the supplemental coolant causes collapse of bubbles otherwise generated by the heat producing fuel rods thereby permitting the supplemental coolant to effectively and efficiently carry away heat generated in the core.

Abstract: A system is provided for the relief of excess pressure from the hot leg of a nuclear reactor to the cold leg on the occurrence of a loss of coolant accident. This system includes a conduit connecting the hot leg with the cold leg. The conduit further includes a check valve which is operated on the basis of differential pressure so that during normal operation the valve is closed.

Abstract: A nuclear reactor construction comprising a fast reactor core submerged in a pool of liquid sodium in a primary vessel. A collecting tray for core debris is submerged in the pool below the core. The collecting tray comprises a base plate constituting a plane tube sheet while the wall of the tray constitutes an annular tube sheet. Coolant conducting tubes are end received in the tube sheets. An internal skirt of the primary vessel overlaps the wall of the tray.

Abstract: A device for retrieving data such as individual names, firm names, addresses, telephone numbers, and so forth, which is constructed in a handy and compact type, and which comprises a rotatable data recording member having a plurality of data indicating parts, a plurality of data retrieving members corresponding to the data indicating parts of the rotatable data recording member, a drive mechanism to rotate the data recording member, and a control mechanism to cause the drive mechanism to stop by operating one of the data retrieving members, and to cause the data indicating parts of the data recording member to the data retrieving member to be presented for reading out.

Abstract: An illustrative embodiment of the invention provides pressure relief valve means for the core support cylinder of a nuclear reactor vessel during a failure or accident of the nuclear reactor system. The valve means is responsive to differential pressure across the valve which in one direction sealably seats the valve plate against the valve body, and which, in the other direction opens the valve for pressure relief of the cylinder. Moreover, the valve means is provided with energy absorbing means which limit the impact load of an "explosively" opening valve on the reactor vessel wall.