Abstract: Reactor pressure vessel inspection apparatus which permits the non-destructive testing of the vessel lower head, shell and top flange taper areas without equipment modification. The inspection apparatus includes an articulated joint assembly which permits a transducer support arm to be rotated about three intersecting axes, the three axes defining two pair of transverse axes.

Abstract: A standpipe runs up from a liquid storage vessel located between the safety vessel of a nuclear reactor and the safety enclosure around it and connected by a pressure equalization line to the interior space of the safety vessel. Undesired pressure increases in the interior of the safety vessel are absorbed by pushing water out of the storage vessel up the standpipe to a discharge above the safety vessel which is still within the safety enclosure. With sufficient pressure, the liquid, which may be conveniently water, flows from the standpipe to an overflow collar at the top of the safety vessel from which it runs down over the surface of that vessel to cool it. Water that evaporates is collected on the interior wall of the safety enclosure and also percolates down to the base of the safety enclosure, from which it is pumped back to the overflow collar, from which it can flow back into the pressure vessel when the pressure inside the safety vessel of the reactor goes back to normal.

Abstract: A laser using heat and thermionic electrical output from a nuclear reactor in which heat generated by the reactor is utilized to vaporize metal lasants. Voltage output from a thermionic converter is used to create an electric discharge in the metal vapors. In one embodiment the laser vapors are excited by a discharge only. The second embodiment utilizes fission coatings on the inside of heat pipes, in which fission fragment excitation and ionization is employed in addition to a discharge. Both embodiments provide efficient laser systems that are capable of many years of operation without servicing. Metal excimers are the most efficient electronic transition lasers known with output in the visible wavelengths. Use of metal excimers, in addition to their efficiency and wavelengths, allows utilization of reactor waste heat which plagues many nuclear pumped laser concepts.

Abstract: A plurality of detectors (12) are disposed within a bore hole (14) for ascertaining the frequency and trajectory of high energy muons which penetrate through the earth. This information is converted by data processor (42) into an integrated density value of the earth for incremental angular lines of sight extending through spaced apart elevations along the detectors (12). The data processor (42) uses a tomographic analysis process to combine together all of these integrated density values for all of the elevations of interest to calculate the densities of discrete spatial volumes composing the underground region being investigated. Detectors (12) produce electrical signals indicative of the trajectory of the passing muon. The signals are recorded by time-to-digital convertor ("TDC") units (30).

Abstract: Communications security between a host computer and another remote computer or terminal is ensured by a means of a two-tiered cryptographic communications security device and procedure. A master key is used to encrypt a first session key. The session key encrypted under the master key is transmitted from a remote facility to a host computer. At the host computer, the session key is decrypted and stored, a second and different session key is then generated, encrypted under the master key and transmitted to the remote facility where it is utilized as the facilities session decryptor key. Because the session key utilized for transmission of data between the remote facility and the host differs from the session key utilized for transmission of data between the host and the remote facility, communications security is increased.

Abstract: An arrangement for inspecting a reactor vessel immersed in a water-filled tank (31) comprises a mast carriage which is arranged for movement around the opening of a reactor vessel and which has fixedly connected thereto a mast which carries a track means (10) on which inspection apparatus (19) can be driven. To render it unnecessary to lift the mast carriage and mast into the reactor hall when, for example, replacing inspection apparatus, there is arranged, in accordance with the invention, on the upper end (20) of the mast a docking unit (21) which is provided with a second track means (22) connecting with the first track means (10). A carriage supporting the inspection apparatus can be driven onto the second track means.

Abstract: In a data communication network which includes terminals interconnected via a central switch, a process for verifying the identity of a terminal user who is provided with secret data associated with his identity. In carrying out the verification process, the secret data is first encrypted at the terminal under a transfer-in key for transmission to an associated data processing system. When it is determined that the terminal user maintains an account at the associated data processing system, a first translate operation is performed to translate the data from encryption under the transfer-in key to encryption under an authentication key, both of which keys are protected under other keys which are different from each other, thereby providing an authentication parameter which may be used to verify the identity of the terminal user.

Abstract: Machine for monitoring internal equipment of a nuclear reactor, when stored outside the reactor vessel in the swimming pool of the reactor, comprising a first longitudinal carriage (16) movable on rails (14) on the bottom of the swimming pool, a transverse beam (46) movable on the first carriage (16), a second transverse carriage (61) bearing monitoring instruments (65) and movable on the beam (46), and an arrangement for moving the beam (46) in predetermined steps on the first carriage (16), and the second carriage (61) on the beam (46).

Abstract: A fuel assembly for a boiling water reactor comprises a plurality of vertical fuel rods (1) and is furnished with a fuel channel device. The fuel rods are arranged with their lower ends resting on a bottom plate and positioned by means of a plurality of spacers (6) attached to the casing. The freedom of movement of the fuel rods in the upward direction is limited by means of a top plate (12) arranged above the upper end surfaces of the fuel rods (1).

Abstract: Simultaneous photon and neutron interrogation of samples for the quantitative determination of total fissile nuclide and total fertile nuclide material present is made possible by the use of an electron accelerator. Prompt and delayed neutrons produced from resulting induced fissions are counted using a single detection system and allow the resolution of the contributions from each interrogating flux leading in turn to the quantitative determination sought. Detection limits for .sup.239 Pu are estimated to be about 3 mg using prompt fission neutrons and about 6 mg using delayed neutrons.

Abstract: A portable instrument for measuring induced Cerenkov radiation associated with irradiated nuclear fuel assemblies in a water-filled storage pond is disclosed. The instrument includes a photomultiplier tube and an image intensifier which are operable in parallel and simultaneously by means of a field lens assembly and an associated beam splitter. The image intensifier permits an operator to aim and focus the apparatus on a submerged fuel assembly. Once the instrument is aimed and focused, an illumination reading can be obtained with the photomultiplier tube. The instrument includes a lens cap with a carbon-14/phosphor light source for calibrating the apparatus in the field.

Abstract: A compression hub (10) for use in a fusion reactor system comprising a multiplicity of compression plates (24, 24') that are polygonal in configuration, and which are arranged in vertically stacked, substantially abutting relation to each other. The compression plates (24, 24') are suitably interconnected, such as by welding, around the periphery thereof so as to provide a compression hub (10) that is in the form of a unitary structure. Each of the compression plates (24, 24') is provided with fluid flow means (30, 32, 30', 32'). The fluid flow means (30, 32, 30', 32') of the compression plates (24, 24') cooperate with one another to establish a fluid flow path for coolant through the compression hub (10). Each of the compression plates (24, 24') is further provided with eddy current prevent means operable to impede the circulation through the plates (24, 24') of eddy currents induced by changes in the magnetic flux field.

Abstract: A generator of a TE.sub.O mode wave beam, particularly adapted for confining plasmas, comprises a laser device for generating an electromagnetic wave having at least a TM.sub.O mode component. The TM.sub.O mode component is filtered by parallel sided plates or refractive surfaces disposed at the Brewster angle for the TM.sub.O component to derive an intermediate wave beam. A TM.sub.O -TE.sub.O mode converter shifts the TM.sub.O mode intermediate wave polarization vector by an angle of .pi./2 radians.

Abstract: A fission chamber detector system for monitoring neutron flux density in a nuclear reactor utilizes a unique coaxial cable carried through a flexible metal hose to provide sufficient signal quality to allow a preamplifier and signal conditioning unit for amplifying and conditioning neutron signal pulses produced by the fission chambers to be far enough away from the fission chambers as to be located outside of the containment vessel for the reactor. Reactor power and rate-of-reactor-power-change signals produced for overlapping power ranges from a countrate circuit and a mean square voltage circuit are aligned by a voltage controlled switch and a slave switch without causing spurious transients in the rate-of-change signals. Power signal indications are provided over 12 decades.

Abstract: The nuclear reactor container of a boiling water reactor has a dry well and a pressure suppression chamber. The level of the radioactivity in the cooling water filling the pressure suppression chamber is measured by a liquid radiation monitor. An iodine monitor measures a level of the radioactivity of the iodine in the space above the surface of cooling water in the pressure suppression chamber, while a noble gas monitor measures a level of the radioactivity of noble gas in the same space. Outputs from the liquid radiation monitor, the iodine monitor and the noble gas monitor are delivered to an accident judging device which makes judgement as to occurrence of perforation of fuel rods and melt down of fuel rods in the event of a Loss Of Coolant Accident (LOCA), the result of which is displayed at a display device.

Abstract: A tagging gas releasing element which is contained in a nuclear fuel rod to release a tagging gas for detecting a failed fuel. The element comprises an inorganic solid material holding the tagging gas therein. The tagging gas is composed of a rare gas, and is held in the inorganic solid material in an injected or adsorbed state.

Abstract: A system and method for the loading of spherical nuclear fuel in vertical fuel rods. The system includes a fuel rod support, a glovebox, a weighing station system, a means for feeding spherical fuel to the fuel rod and transportation means for moving the fuel between parts of the system.

Abstract: A feeding apparatus for the loading of the spherical nuclear fuel into a fuel rod. The apparatus feeds fuel of three different diameters into a fuel rod so that the three different sized spheres are appropriately packed to achieve sufficient density of fuel to be used in a nuclear reactor.

Abstract: Combined microwave oscillator, duplexer and mixer apparatus for sensing motion of adjacent objects through use of Doppler-shifted electromagnetic radiation reflections from the objects, with second order and higher even order harmonic emissions being suppressed by modification of the oscillator apparatus.

Abstract: The invention discloses the use of stable isotopes of neon and argon, that are grouped in preselected different ratios one to the other and are then sealed as tags in different cladded nuclear fuel elements to be used in a liquid metal fast breeder reactor. Failure of the cladding of any fuel element allows fission gases generated in the reaction and these tag isotopes to escape and to combine with the cover gas held in the reactor over the fuel elements. The isotopes specifically are Ne.sup.20, Ne.sup.21 and Ne.sup.22 of neon and Ar.sup.36, Ar.sup.38 and Ar.sup.40 of argon, and the cover gas is helium. Serially connected cryogenically operated charcoal beds are used to clean the cover gas and to separate out the tags. The first or cover gas cleanup bed is held between approximately 0.degree. and -25.degree. C. operable to remove the fission gases from the cover gas and tags and the second or tag recovery system bed is held between approximately -170.degree. and -185.degree. C.