[en] Systems for remotely detecting the presence or absence of a fluid in a vessel comprising a probe with two electrodes, the electric resistance between them depending on the condition to be detected. The electrodes, which are insulated with respect to the earth, are connected through a first pair of leads to the terminals of a current generator and, through a second pair of leads, to the terminals of a current and or voltage variation detection circuit. It can be used for monitoring the state of the core of a nuclear reactor pond, or of its protective casing. In the event of an operational incident occurring in the reactor, the water likely to be present between the probe electrodes is a highly deionized water, the presence of which could not be revealed by conventional probes. The probe can be made without difficulty from materials withstanding nuclear radiations

[en] A high-precision level indicator is proposed, mainly for heavy water level indication in a nuclear reactor. The sensor has increased resistance against corrosion of the needle contact placed inside the system of two electrodes having the shape of lidless vessels. The inner electrode is placed inside the outer electrode at a distance of at least 0.5 mm from the electrode walls and bottom. The principle is implemented that the rate of galvanic element deposition may be reduced by surrounding the oscillating needle contact with a system of electrodes supplied by electric current such that a sufficiently intesive electrolytic deposition takes place of substances dissolved in water on the electrodes and unwanted impurities in the vicinity of the needle contact are eliminated. (F.M.)

[en] A probe is designed for measuring the level of liquids in pressurized and non-pressurized storage tanks. An insulated electrode runs through the centre of the probe and with the probe body it forms a capacitor whose capacitance depends on the height of the level between the insulated electrode and the inner wall of the probe. The probe may be used for storage tanks of liquids in nuclear power with a minimum level height, e.g., 100, 200 or 500 mm. (J.C.)

[en] The invention concerns an appliance for measuring the level of a molten metal of the kind using the variation of the mutual inductance between two imbricated windings depending on the level of the free area of the molten metal in the range of levels taken up by the windings. It has a particularly significant use in measuring the level of liquid sodium, especially in nuclear facilities where sodium is used as coolant

[en] This invention concerns a level indicator of liquid conductors. The device used is a coil with a twin-wire winding operating inductively, placed in a liquid conductor bath such as a bath of liquid metal. The primary winding is controlled from a constant current source and the output signal collected on the two-wire secondary winding, depends on the secondary winding being effectively shorted by immersion in the conducting liquid

No abstract available

[en] The methods used for continuous measuring of levels in liquid metal containers are described and evaluated. In view of the low accuracy of the measuring a new method was designed and tested using a high-frequency line introduced into the liquid metal container. (F.M.)

[en] In a filling level measuring installation with a radioactive radiator, which can be rotated within a lead shield from a peripheral operating position opposite the measuring receiver into a central safety position, a second radiaiton detector is arranged on a rearward extension of the measuring path in such a manner that in the safety position, its distance from the radiator is smaller than in its operating position, so that the output signal of the second detector can serve for monitoring the radiator position

[en] Reported inaccuracies in water level instruments at nuclear power plants are being investigated by the Nuclear Regulatory Commission. In April, 1991, NRC received a report from Northeast Utilities detailing inaccuracies in a pressurized level instrument caused by accumulation of non-condensible gases in the instrument's condensing pots. The instruments measure the depth of cooling water. Further tests found a possible indication error of about plus 40%. Last month, NRC issued an information notice to all licenseeholders, saying that the problem may affect indicators at both PWRs and BWRs. The BWR Owners Group had asked the manufacturer to study the issue. Based on GE's analyses, instruments will function as designed to start the plant's safety systems when needed. GE also stated that it does not believe that this is a generic problem affecting all BWRs, saying that if there is any correction to be made, it is a configuration problem...how the instruments are laid out at a particular facility

[en] The main characteristics of the design of radioisotope level indicators for bath glass furnaces are described. Some experimental data which allow to determine attainable parameters of the level indicators for industrial conditions are given