Abstract: A heat treatment method for inhibiting irradiation induced stress corrosion cracking in stainless steel and related nickel-chromium alloys.

Abstract: An automated analysis system includes a pair of sample selection subsystems whose operations are coordinated by a host computer pursuant to developing analytical data useful to a process computer in controlling an industrial process. Each subsystem includes a sample selection computer operating to control one or more multiport valves in extracting fluid samples on a scheduled or demand basis from sample loops connected with the various process streams involved with the process. The extracted samples are injected into a spectrometer for analysis. An instrument computer converts the spectrometer responses to analytical data indicative of the constituent concentrations found in an analyzed sample.

Abstract: An electrical switching system comprising a relay having a photoelectric element comprising a photodiode, with first and second electrodes and a photosensitive portion. The photosensitive portion is responsive to optical stimulation for electrically coupling the first and second electrodes, permitting transmission of electrical current between them whereby the relay can be connected to a source of electrical power. The electrical switching system comprises a pair of such relays which cooperate through optical signals to operate the switch system. Also a part of the switching system is an optical rotary switch for controlling the operation of the switch system. A further aspect of the disclosed invention comprises a nuclear power generating apparatus including a monitoring arrangement operated by the electrical switching system of this invention.

Abstract: A control rod driveline and grapple is disclosed for placement between a control rod drive and a nuclear reactor control rod containing poison for parasitic neutron absorption required for reactor shutdown. The control rod is provided with an enlarged cylindrical handle which terminates in an upwardly extending rod to provide a grapple point for the driveline. The grapple mechanism includes a tension rod which receives the upwardly extending handle and is provided with a lower annular flange. A plurality of preferably six grapple segments surround and grip the control rod handle. Each grapple rod segment grips the flange on the tension rod at an interior upper annular indentation, bears against the enlarged cylindrical handle at an intermediate annulus and captures the upwardly flaring frustum shaped handle at a lower and complementary female segment. The tension rods and grapple segments are surrounded by and encased within a cylinder.

Abstract: A monitor for detecting airborne radioactive particulates is disclosed. An elongate strip of filter paper is fed across first and second air inlet ports of a collection chamber. Ambient air is selectively drawn into the chamber through a selected one of the inlet ports and out an through outlet port. Particulates trapped on an area of the filter paper in alignment with the open inlet port are detected after advancing the strip area into alignment with the closed inlet port. A radiation detector mounted on a movable arm is selectively positioned over the closed inlet port to detect the trapped radioactive particulates, while a new sample is collected at the open inlet port. Exposure of the detector surface to corrosive materials is avoided and the detector can be positioned close to the filter strip to maximize counting efficiency and energy resolution. A microprocessor controls the functions of the monitor and allows continuous unattended operation.

Abstract: Stress corrosion cracking of austenitic stainless steel or nickel-based alloys attributable at least in part to exposure to irradiation is reduced with a specific heat treatment.

Abstract: A uranium oxide product is formed in a gaseous reaction medium from uranium hexafluoride by interaction with a fuel gas such as hydrogen and oxygen. Oxide content and particle properties of the uranium oxide product are governed by the improved method and the apparatus for carrying out the method. An improvement is provided by applying a quenching gas to quench the conversion reaction of uranium hexafluoride to uranium oxide, and a combustion reactor apparatus which enables the application of the quenching gas is also provided.

Abstract: Coolant recirculation arrangement for a nuclear reactor including a plurality of vertically oriented tubular conduits arranged in spaced relation between an unshrouded nuclear core and the inner pressure vessel wall for conducting coolant from an upper plenum above the core to a lower plenum below the core.

Abstract: A method and binder composition for prolonging the induced plasticity of a particulate ceramic material admixture comprising uranium dioxide and a fugitive binder, and product thereof, for subsequent compaction by compression molding in the manufacture of nuclear fuel pellets. The fugitive binder comprises a reaction product of an amine carbonate or amine carbamate and ammonium oxalate reacted with uranium dioxide at a temperature of at least 65.degree. C. The uranyl oxalate-carbonate reaction product has the composition of (UO.sub.2 (CO.sub.3) (C.sub.2 O.sub.4). 2H.sub.2 O). 2H.sub.2 O.

Abstract: A system for converting heat energy into electricity includes a conversion cell comprising a pair of spaced-apart electrodes having an electrolyte therebetween. The electrolyte is selected to pass negatively-charged hydrogen ions and to inhibit the passage of atomic hydrogen and positive hydrogen ions. Inducing a flow of hydrogen through the cell, a current may be generated between the electrodes as electrons are gained by the hydrogen as it enters the cell and lost by the hydrogen as it leaves the cell. In the preferred embodiment, hydrogen flow is induced by reacting the hydrogen leaving the cell with lithium or sodium to form the metal hydride. The metal hydride is then thermally decomposed to release the hydrogen and the molten metal to be recycled to the cell. In this way, the thermal energy used to decompose the metal hydride is converted into electrical energy by passing the hydrogen through the conversion cell.

Abstract: A monitored nuclear reactor parameter, such as a startup range neutron monitoring signal, is filtered at a filter having a preselected time constant and amplified with the output being passed to one channel of a two channel comparator. The level of the amplification and the filter time constant are chosen to discriminate between normally increasing startup neutron density including the prompt-jump effect and exponentially increasing neutron density due to the occurrence of reactor casualty in view of the design parameters of the reactor. This same startup range neutron monitoring signal is passed unprocessed to the other channel of the two channel comparator. Comparison of the two signals is made with the binary output of the comparator flagging excess of the unprocessed signal over the filtered and amplified signal. Presence of the appropriate reactor flag is typically used to cause rod withdrawal blockage and/or SCRAM.

Abstract: In a modular liquid-metal pool breeder reactor, a radiant vessel auxiliary cooling system is disclosed for removing the residual heat resulting from the shutdown of a reactor by a completely passive heat transfer system. A shell surrounds the reactor and containment vessel, separated from the containment vessel by an air passage. Natural circulation of air is provided by air vents at the lower and upper ends of the shell. Longitudinal, radial and inwardly extending fins extend from the shell into the air passage. The fins are heated by radiation from the containment vessel and convect the heat to the circulating air. Residual heat from the primary reactor vessel is transmitted from the reactor vessel through an inert gas plenum to a guard or containment vessel designed to contain any leaking coolant. The containment vessel is conventional and is surrounded by the shell.

Abstract: Repair apparatus and a method of repair utilized for securing pressure sensing lines to jet pump diffusers in boiling water nuclear reactors is disclosed. Conventional access is made to the reactor with removal of the jet pump inlet mixer to expose the upwardly disposed frustum-shaped diffuser. The diffuser includes a pressure sensing line mounted by a stand off block. It has been found that this pressure sensing line becomes separated from the diffuser due to vibration and accompanying metal fatigue. A repair is effected by introduction of an arcuate beam configured for live support at each end. This pressure sensing line and stand off block is bracketed by the upper end of a beam to register the line to the stand off block. The lower end of the beam brackets the line and stands off from the diffuser at a second introduced stand off block. The line is provided with two points of support to prevent further dislodging vibration.

Abstract: In a nuclear reactor fuel assembly, a relatively flexible mounting member for mounting a large coolant conducting tube to the lower tie plate whereby excessive side forces on the fuel rod spacers are avoided in the event of lateral displacement of the fuel assembly such as during a seismic event.

Abstract: A reproducible method and stable binder composition for preserving the induced plasticity of a particulate ceramic material admixture comprising uranium dioxide and a fugitive binder, and product thereof, for subsequent compaction by compressing molding in the manufacture of nuclear fuel pellets.

Abstract: An apparatus and method for continuously separating and recovering an organic liquid such as a hydrocarbon solvent from immiscible water and/or other impurities mixed therewith. The apparatus and method comprise a system for treating liquids while continuously flowing therethrough, including in series a gravity separation step followed by a distillation separation step.

Abstract: A flow channel-to-nozzle attachment for a nuclear fuel assembly wherein the flow channel and nozzle are formed of material having different thermal coefficients of expansion, the attachment comprising tapered bars secured to the lower inner ends of the channel which bars are fitted into similarly tapered grooves in the adjacent outer surfaces of the nozzle, the angle of taper being selected such that the tapered bars move more or less deeply into the grooves in the nozzle with temperature changes without bending or stressing the lower end of the channel.

Abstract: An improved method for producing nuclear fuel containers of a composite construction having components providing therein a barrier system for resisting destructive action by volatile fission products or impurities and also interdiffusion of metal constituents, and the product thereof. The composite nuclear fuel containers of the method comprise a casing of zirconium or alloy thereof with a layer of copper overlying an oxidized surface portion of the zirconium or alloy thereof.

Abstract: A probe is disclosed for detecting the absence of helical springs from an array of mutually spaced springs, each mounted on a separate shank. The probe includes an elongate arm having a pair of pawls mounted in an aperture at one end of the arm, biased to extend from the aperture. During probing, the helical springs normally prevent the pawls from assuming their extended positions outside the aperture, which is urged by the applied biasing force. If a helical spring is missing from the array, the appropriate pawl pivots outward into its extended position and becomes lodged against the springless shank to lock the probe in position. Its location in the array then indicates where a spring must be replaced.

Abstract: An improved process for producing powdered uranium dioxide from a solution of uranyl nitrate which is suitable for the manufacture of fuel for nuclear reactors. The process is continuous and comprises an incremental precipitation of soluble uranyl nitrate with ammonium hydroxide which is interrupted with an intermediate aging period. The precipitate of ammonium uranate solids is dried and thermally converted to a powdered oxide of uranium.