Abstract: An alpha particle monitor is disclosed which includes a flow-through linear ionization chamber with means to pass therethrough gas-borne radioactive matter exhibiting alpha decay, such as, radon gas, air-borne plutonium or uranium dust, etc., and an amplifier sensitive to charges on the order of 10.sup.-14 coulombs associated with an alpha emission event. In a preferred form, the amplifier includes a solid state operational amplifier having a stray feedback capacitance sufficiently low to provide, in response to an alpha decay event, an output pulse with a measurable voltage amplitude, e.g., 0.1-1.0 volts, and a feedback resistance sufficiently high to provide the amplifier with a time constant such that the output pulse produced in response to an alpha emission event has a width sufficient to facilitate detection in the presence of noise.

Abstract: A scintillation cell having cylindrical symmetry, thickened walls, and components with different coefficients of thermal expansion. A pliable epoxy bonds the components together and accommodates their varying expansions during temperature changes. The glass through which passes the luminescence produced by the radioactive particles to the photomultiplier tube sits inside of the cylindrical metal tube to which it attaches. This recessed configuration protects the glass when the cell contacts a flat surface. Producing the cell involves spraying the luminescent material onto the inside of a metal tube. The metal tube receives the luminescent material while both heated and spinning. The spinning, heated cell can receive a multitude of coats of material at each application and, thus, prepares for use rapidly and economically. Subsequently, the substantially clear glass bonds sufficiently far inside of the tube over its open end to provide the recessed configuration.

Abstract: A leak detection system integral with a wall of a building used to fabricate nuclear fuel elements for detecting radiation leakage from the nuclear fuel elements as the fuel elements exit the building. The leak detecting system comprises a shielded compartment constructed to withstand environmental hazards extending into a similarly constructed building and having sealed doors on both ends along with leak detecting apparatus connected to the compartment. The leak detecting system provides a system for removing a nuclear fuel element from its fabrication building while testing for radiation leaks in the fuel element.

Abstract: Method of determining the activity concentration of the radio nuclides in waste gases of nuclear power plants by bleeding a part of the gas stream, compressing it to a high superatmospheric pressure, passing the compressed gas into a high pressure chamber where the specific nuclides are measured by means of a calibrated Ge (Li) detector, and returning the gas from the chamber at reduced pressure to the gas stream. The activity concentration of the gas in the high-pressure vessel permits measurement of the specific nuclides, and also permits detection of waste gas activities which are below the customary detection limits.

Abstract: An extremely sensitive metallic vapor detection method primarily for use in a sodium cooled nuclear reactor containment. Sodium vapor, or a compound derived from it, is allowed to react with a radioactively tagged substance so as to produce a radioactive gas. The released gas is monitored by a nuclear counter, which provides a direct indication of the presence of metallic vapor. The method is sensitive to the presence of metallic vapor in a gaseous environment in the range of 10.sup.-16 grams per cubic centimeter.

Abstract: Certain internal parts of a gas cooled dynamoelectric machine may be coated with selected materials which will decompose at elevated temperatures to give off sub-micron particles into the machine gas coolant called pyrolysates. The presence of such pyrolysates in the machine gas coolant is indicative of localized overheating within the dynamoelectric machine. A detector is known for sensing the occurrence of these pyrolysates and hence a monitoring system has been devised for giving an early warning of machine overheating. Occasionally, oil mist particles from the machine may become entrained in the machine gas coolant and cause a false overheating signal from the detector. A second detector has been devised which may be used in combination with the first detector to provide a redundant monitoring system which will provide immediate validation of the presence of pyrolysate particles and which monitoring system is testable on line.

Abstract: An improved detector apparatus is provided in combination with a gas cooled dynamoelectric machine for detecting the presence of pyrolysate products in the machine gas coolant indictive of localized overheating of certain dynamoelectric machine parts. The detector apparatus is of the type which analyzes an ionized gas sample by measuring the current flow in the gas sample. A decrease in current flow is indicative of the presence of submicron particulates. The present invention resides in heating the gaseous sample to eliminate more volatile submicron particulates so that the output signal from the detector apparatus is indicative only of the presence of pyrolysate products resulting from the localized overheating of certain dynamoelectric machine parts.

Abstract: A shock-, vibrations- and tampering-proof attachment means of an object, h as a signal producing insert of an ionization alarm system coaxially and non-rotatably to a support, such as for land-, marine- and air vehicles provides a spring assembly with a spring and biased coaxial protrusion in the bottom of the object with a helically wound canal running through the protrusion having end orifices in its surface. The support is provided with a U-shaped fork fixed with its yoke in it. A connecting means equipped with a rod traverses the protrusion perpendicularly to its axis. The rod is fastened to both free ends of the yoke. Optimum shapes and dimensions of the respective parts are established, also with the view of maintaining a minimum size of the object itself. The object with the fixed protrusion is mounted by rotation thereof to the support, thus hiding the attachment means and making them vibration proof and inaccessible from the outside.

Abstract: Apparatus is disclosed for detecting nuclear fuel leaks within nuclear power system reactors, such as high temperature gas cooled reactors. The apparatus includes a probe assembly that is inserted into the high temperature reactor coolant gaseous stream. The probe has an aperture adapted to communicate gaseous fluid between its inside and outside surfaces and also contains an inner tube for sampling gaseous fluid present near the aperture. A high pressure supply of noncontaminated gas is provided to selectively balance the pressure of the stream being sampled to prevent gas from entering the probe through the aperture. The apparatus includes valves that are operable to cause various directional flows and pressures, which valves are located outside of the reactor walls to permit maintenance work and the like to be performed without shutting down the reactor.

Abstract: A synchronized accumulating radiodetector comprises a series of longitudinally connected counting tubes of equal inner volume, a plurality of switching units adapted to be synchronized with the flow speed of radioactive substance traveling with reference to the counting tubes, and a plurality of counting accumulators for counting the radioactivity and accumulate number of the radioactivity. The radiodetector has an accumulated counting output mechanism, from which output is sent to auxiliary recording or displaying unit.

Abstract: Apparatus for monitoring the mass concentration of atmospheric pollutants above and below a predetermined size. A receptacle has an air inlet and outlet. Air is continuously drawn through the inlet and thence through the receptacle and the outlet. A first collector in the receptacle collects pollutants above the predetermined size. This first collector is movable through a first station and collects pollutants above the predetermined size from the air entering the receptacle through the inlet on successive areas thereof. A second collector in the receptacle collects pollutants below the predetermined size. This second collector is movable through a second station and collects pollutants below the predetermined size from the air which has passed the first station on successive areas thereof. A holder is provided for a first source of radiation which passes through the area of the first collector at the first station.

Abstract: Radon is directly measured by a portable device which is attached to the l of a mine or other area from which the gas may be emanating. The radon is collected and directed to an instrument having a gas proportional counter. To prevent build up of radon daughters on the gas proportional counter, with consequent high alpha particle background, a moving film surrounds the counter and carries away the radon daughters.

Abstract: A smoke detector is disclosed which comprises an inner electrode, an intermediate electrode with a hole for passing radioactive rays therethrough, an outer electrode having openings for allowing smoke to flow therethrough, and one radioactive source, the inner and intermediate electrodes forming an inner ionization chamber, the intermediate and outer electrodes forming an outer ionization chamber, the radioactive source being disposed in the inner ionization chamber. A proper quantity of radioactive rays from the radioactive source is applied into the outer ionization chamber through the hole provided in the intermediate electrode.