Accurate and controlled drive for the control rod is from an electric motor. A hydraulic arrangement is provided to balance a piston against which a control rod is urged by the application of fluid pressure. The electric motor drive of the ...
DOEpatents
BS>A slow-acting shim rod for control of major variations in reactor neutron flux and a fast-acting control rod to correct minor flux variations are employed to provide a sensitive, accurate control system. The fast-acting rod is responsive to ...
A hydraulically operated control rod actuator was developed for use with large water-cooled reactors. It is capable of actuating control rods weighing up to 2300 pounds. Pressurized primary reactor water is used as the hydraulic fluid, and the design provides smooth, accurate ...
Energy Citations Database
An arrangement is described for accurately moving fuel (and possibly control) rods apart or together in a reactor, enabling the reactor to be controlled and eliminating the need for control or moderating rods. The fuel rods are arranged in rows ...
In order to reduce the time needed to perform control rod calibrations and improve the accuracy of the results, a technique for a measurement, analysis, and tabulation of integral rod worths has been developed. A single series of critical rod positions are determined at constant low power to reduce the waiting time ...
A more accurate rod-drop method for measuring the shutdown reactivity available from control rods is outlined. Corrections due to flux shape changes can be applied to the measurements, and the use of pretimed scram equipment provides excellent reproducibility. Finite rod-drop times are ...
A robotic system for remote underwater withdrawal of the fuel rods from fuel modules of a light water breeder reactor includes a collet/grapple assembly for gripping and removing fuel rods in each module, which is positioned by use of a winch and a radial support means attached to a vertical support tube which is mounted over the fuel module. A ...
DOE Information Bridge
A quick releasable mechanical drive system suitable for use in a nuclear reactor is described. A small reversible motor positions a control rod by means of a worm and gear speed reducer, a magnetic torque clutch, and a bell crank. As the control rod is raised to the operating position, a heavy coil spring ...
... (Author). Descriptors : *CONTROL RODS, *NUCLEAR POWER PLANTS, MAINTENANCE, REACTOR CONTROL, REACTOR FUEL RODS. ...
DTIC Science & Technology
... Shipment of Radioactive Control Rods from ... HANDLING), (*TRANSPORTATION, CONTROL RODS), CONTAINERS, RADIATION MONITORS ...
This application describes a mechanism for providing precise (microradians) angular adjustment for high resolution adjustable mounts and platforms used to design optical elements. The mechanism includes temperature-controlled rods having internally embedded heater elements and thermistors attached to a stable platform. The heaters and thermistors are ...
NASA Astrophysics Data System (ADS)
In a reactor containing more than one control rod, which includes all reactors licensed in the United States, there will be a 'coupling' or 'shadowing' of control rod flux at the location of a control rod as a result of the flux ...
A method is proposed of estimating experimentally the reactivity worth of multiple control rods by single-rod experiment. In the method, the contribution of each control rod to the multiple-rod worth is obtained by the measured single-rod worth, to ...
National Technical Information Service (NTIS)
To permit more accurate evaluation of the incentives for isotopes producing control rods a determination was performed of the tritium production which would result from conversion to lithium HCR`s. A cursory examination of the gains resulting from the use of lithium shows that a significant amount of tritium could be produced in this ...
Experiments were conducted at the Annular Core Research Reactor (ACRR) to increase the fidelity of the control rod integral reactivity worth curve. This experiment series was designed to refine the integral reactivity curve used for pulse yield prediction and eliminate the need for operator compensation in the pulse setup. The experiment series consisted ...
The object of this test was to obtain data concerning the reactivity of the horizontal rods in the E-N fuel loading at H Reactor. An accurate calibration of the control rods could then be used to provide a more accurate measurement of the other reactivity variables associated with the E-N ...
A novel wading rod is provided for safe, accurate, convenient and effective use in measuring stream flow velocity which comprises a base, lightweight non-metallic rods, including a front stationary rod and a rearward adjustable sliding rod with locking me...
A reactor control mechanism is described wherein the control is achieved by the partial or total withdrawal of the fissile material which is in the form of a fuel rod. The fuel rod is designed to be raised and lowered from the reactor core area by means of two concentric ball nut and screw assemblies that ...
A simple prescription to account for spatial feedback weighting effects in RDA (rod drop accident) point-kinetics analyses has been derived and tested. The point-kinetics feedback model is linear in the core peaking factor, F/sub Q/, and in the core average void fraction and fuel temperature. Comparison with detailed spatial kinetics analyses indicates that the improved ...
BS>One-velocity treatments of thermal neutron transport have proved inadequate whereas multigroup methods may be so time consuming as to become impractical. The few thermal-group calculations investigated lie between these extremes. Few-group calculations in typical power peaking and control rod worth studies are found to be both rapid and ...
An apparatus is describe which, by purely electrical methods, gives very accurately the correct contact break poin- t for the drive of the carrier magnet within the check -zone. With this apparatus the magnet drive does not approach the rotor/sup 4/. The apparatus also indicates whether the absorber part of the rods is still ...
Designed for gas-heated ceramic range-top cooking surfaces, this thermal cut-out incorporates a temperature sensor that extends from a snap switch housing. The cut-out allows low switching frequency and highly accurate temperature control, preventing the glass ceramic surface from overheating. The sensor consists of a rod inside a ...
Unexpected deviations of ex-core neutron detector signals were observed during a voyage of the Japanese nuclear ship, Mutsu. From detailed three-dimensional analyses, this phenomenon was determined to be caused by an asymmetrical neutron source distribution in the core due to a small misalignment between the two control rods of a ...
System for preventing erroneous operation of control rods for securing a safety control of a nuclear reactor is described. The erroneous operation preventing system is comprised of a control rod objective position setting means for setting an objective position of a control ...
The accurate prediction of control rod worths has been of great concern in the United States. Optimum control configurations need to balance several often conflicting requirements of control through the operating cycle, while maintaining acceptable power shapes, safety considerations of ...
Three types of control rods were used in the Plum Brook reactor: two hydraulically controlled regulating rods to provide precise control of the reactor ...
NASA Website
A proposed new Technical Standard (DPSTS-105-2.09, Safety Rod and Control Rod Heat Generation) specifies that the calculated operating heat flux for safety rods and control rods, that are assumed to be in the reactor during operation, shall be no greater ...
A control rod driveline and grapple for engaging and releasing a control rod from a control rod drive is described comprising an enlarged control rod handle including an upwardly flaring frustum and a rod ...
A reactor control rod is designed which is axially movable in a tube inside the reactor. The control rod is lowered or raised by a hydraulic motor controlled by the reactor coolant. Means is provided for releasing the control rod for quick ...
Two anticipated transient experiments simulating an uncontrolled control rod withdrawal event in a pressurized water reactor (PWR) were conducted in the Loss-of-Fluid Test (LOFT) Facility at the Idaho National Engineering Laboratory. The scaled LOFT 50-MW(t) PWR includes most of the principal features of larger commercial PWRs. The experiments tested the ...
A variable flow control for a control rod assembly of a nuclear reactor that depends on turbulent friction though an annulus. The annulus is formed by a piston attached to the control rod drive shaft and a housing or sleeve fitted to the enclosure housing the control ...
A control drive is described for the control rod for a sodiumcooled nuclear reactor with a pivoting cover consisting of a braced support and a motor device as well as an installation for the accelerated ejection of a control rod for emergency shutdowns. The control ...
A nuclear reactor control rod mechanism is designed which mechanically moves the control rods into and out of the core under normal conditions but rapidly forces the control rods into the core by catapultic action in the event of an emergency. (AEC)
