[en] The invention concerns a thermocouple receptacle and a device to be located inside a reactor, that provides a positive seating for the thermocouples immediately next to the outlet of the fuel assemblies and allows a visual inspection to be made of the position of the thermocouples

[en] A thermocouple with several electrodes is presented, its distinguishing features being a very low bulk, a small number of electrodes and a single envelope. Compared with known types of thermocouple it offers a smaller quantity of metal when used in the core of nuclear reactors. In addition the thermocouple has a small diameter and great length, up to 50m or more, and can therefore fit into narrow channels of any shape and be connected to secondary instruments without the need for compensation wires

No abstract available

[en] The ionisation chamber is used for the measurement of powerful neutron and γ radiation at temperatures up to 800⁰C in the fission zone of a nuclear reactor. It consists mainly of a cylindrical housing filled with argon, a rod electrode lying on the axis of the cylinder, coaxially arranged protective electrode, and distance and insulating pieces between the elektrodes and the housing. A collector electrode made of individual, separate pieces of tube lies outside the protective electrode. The electrical connection is via a three-core coaxial cable, whose central conductor is connected to the rod electrode, whose inner sheath is connected to the protective electrode and whose outer sheath is connected to the casing. For an external diameter of less than 6 mm the lenght of the miniature ionisation chamber can be designed in 10 mm steps to 5 - 7 metres. For measuring the neutron flux, the surface of the piece of tube is covered with uranium enriched with the isotope U 235. Thus the sensitivity of the ionisation chamber is reduced with regard to thermal neutrons. (DG) 891 HP

[en] This invention refers to a detector of particles that enables accurate determinations to be effected at high temperature, irrespective of the particle flux to which it is subjected (for example, a neutron flux in the core of a reactor) and preferentially is of elongated shape and particularly reduced radial section. According to the invention, the specifications of this detector include a body in a single piece, made of a ceramic material, in which are embedded and sealed two concentric tubular electrodes forming between them an annular chamber filled with a gas under pressure and electric wires connecting the electrodes to the outside of the body

[en] The neutron detector consists of a fission chamber and a compensated ionisation chamber for neutron flux between 1 and 10¹⁰/cm²/sec. The maximum flux for neutron detectors in impulse counting operation is limited by the saturation and the minimum which is detectable due to DCα signal noise. The detector contains a small quantity of UO₂ which is deposited on an electrode. Part of the detector is in the form of a compensation chamber. It contains Ra²²⁶. The α signal noise is suppressed by the reduction of the U 234 content in UO₂ to less than 100 ppm. The γ compensation signal can be produced by an external circuit. (DG) 891 HP

[en] The Core Operating Limit Supervisory System (COLSS) digital monitoring system relies on signals from fixed in-core detectors to determine the peak linear heat rate of the fuel and the departure from nucleate boiling ratio thermal margin. Experience with this type of detector indicates that some failures will occur during operation. This paper describes the cause-and-effect relationship between detector failures and those COLSS parameters determined by the detector signals, the statistical methods used to determine the additional penalties incurred by detector failures, and the proposed limiting conditions for operation for the in-core detector system. 11 refs

No abstract available

[en] A study has been made of the effects of various arrangements of the transducers and control rods for a height problem. The BASIRA program has been used with a BESM-6 in detailed analysis of the stability of a system with a complicated distribution of the parameters; however, the situation can be analyzed qualitatively without resort to a computer. Here a homogeneous cylindricl reactor of unit radius with zero boundary conditions. 10 refs

[en] A sensing probe device constituted by a tubular feeler member adapted to be inserted into a reactor-core and by a through-tube coxial with said feeler member, characterized in that feeler member can be telescopically introduced into said through-tube. (author)