Abstract: A process for producing a piezoelectric sensor includes the following steps: a step of providing a housing made of stainless steel; a step of producing a solution of a compound comprising a metal or metalloid element; a step of depositing a layer of the solution over at least one inner surface of the housing; a step of oxidizing the deposited layer of solution; a step of placing a piezoelectric element inside the housing; a step of closing the housing. A piezoelectric sensor obtained by such a process and comprising a closed steel housing, a piezoelectric element arranged inside the housing and a layer of a solution of a compound comprising a metal or metalloid element that is arranged over at least one inner surface of the housing.

Abstract: A nuclear reactor cooled by liquid metal incorporating a passive system for evacuation of the decay heat with a phase change material thermal reservoir and a removable thermally-insulating layer around the phase change material reservoir. A nuclear reactor incorporates an integral system that guarantees: totally passive evacuation of decay heat from the initial moment of the accident; evacuation of power via the primary containment vessel; the presence of a final cold source with a reservoir incorporating an integral exchanger divided into a plurality of parallel tubes between which a phase change material is inserted, the reservoir being surrounded by a thermally-insulating layer that can be detached in a passive manner in the event of reaching a predetermined threshold temperature.

Abstract: A liquid metal cooled nuclear reactor incorporates a fully passive decay heat removal system with a modular cold source. The system which simultaneously ensure decay heat removal in a completely passive way from the moment an accident starts; heat removal through the primary vessel; and reduction in the risk of chemical interaction between sodium (or NaK) and the material acting as the final cold source. The presence of the final cold source provides an improvement over sodium/air or NaK/air exchangers that are used in the prior art.

Abstract: A potentiometric oxygen sensor for measuring the oxygen concentration of a liquid metal, including: a metal tube forming at least one sensor body part; an electrochemical subassembly containing an electrolyte, intended to be in contact with the liquid metal, and a reference electrode contained in the electrolyte, the electrolyte being made of yttrium-doped or calcium-doped hafnia (HfO2), or of thoria (ThO2), which is optionally yttrium-doped or calcium-doped, or of yttrium-doped or calcium-doped zirconia (ZrO2), the reference electrode containing at least one metal and its oxide form at the operating temperature of the sensor, an insert made of a transition metal from group 4 of the Periodic Table or an alloy thereof, arranged between the sensor body part and the electrolyte, the insert being attached to the sensor body part and brazed onto the electrolyte by a brazing joint.

Abstract: A process for producing a piezoelectric sensor includes the following steps: a step of providing a housing made of stainless steel; a step of producing a solution of a compound comprising a metal or metalloid element; a step of depositing a layer of the solution over at least one inner surface of the housing; a step of oxidizing the deposited layer of solution; a step of placing a piezoelectric element inside the housing; a step of closing the housing. A piezoelectric sensor obtained by means of such a process and comprising a closed steel housing, a piezoelectric element arranged inside the housing and a layer of a solution of a compound comprising a metal or metalloid element that is arranged over at least one inner surface of the housing.