Abstract: A liquid absorbent safety rod for a nuclear reactor comprising a reservoir, the upper compartment of which is filled with liquid absorbent under gas pressure communicates with a lower compartment situated in the core of the reactor the lower compartment being filled with gas under pressure by way of a disconnectable hollow rod. By varying the gas pressure in the lower compartment, the quantity of absorbent descending into this compartment may be varied. When the hollow rod is disconnected from the reservoir, all the liquid absorbent falls into the lower compartment.

Abstract: Improvement to a safety device with a solid absorbant which may be used in a water-cooled reactor, essentially constituted by a cylindrical tank placed above the core of the reactor and containing a gas kept under pressure as well as an absorbant in a divided form. The opening device of the tank is sensitive to a depressurization. The tank supplies simultaneously several spouts each leading to a tube implanted in the core of the reactor.This is a continuation, of application Ser. No. 416,140, filed Nov. 15, 1973, now abandoned.

Abstract: Solid absorbent in particle form stored in an intermediate chamber at a position above the reactor core within a safety device container under fluid pressure is driven by the escape of the pressure fluid along a series path from the upper compartment to the lower compartment, into the lower compartment to shut down the reactor when a destructible seal within a pipe carried in the lower compartment ruptures in response to reactor malfunction.

Abstract: A liquid absorbent safety device for a nuclear reactor, constituted by a cylindrical tank comprising two communicating superposed compartments. The upper compartment situated above the reactor is filled with liquid absorbent surmounted by a gas under pressure. The lower compartment situated in the core is filled with gas under pressure and is provided with a connection to the outside terminated by a closing member sensitive to the operating conditions of the reactor. If the reactor begins to malfunction, the closing member is destroyed thereby causing depressurization of the lower compartment and the precipitation of the liquid absorbent into the lower compartment.

Abstract: Method and device enabling the injecting in the cutting groove of a gas coming from a nozzle at a supersonic speed, brought to a temperature which may probably be very high. A device for injecting an auxiliary gas ensures the protection of the front lens of the laser. Increase in the cutting speed.

Abstract: Very porous conductive ceramic substances constituted of diborides and a certain percentage of disilicides of metals in groups IVa, Va, VIa of the periodical classification of elements. Preparing of ceramic substances by sintering of fine powders and of grains of a mixture of diborides and disilicides of metals in groups IVa, Va, VIa in the periodic classification of elements in presence of a fluoride.