Abstract: The device comprises, in addition to a gamma thermometer with two junctions and insulated output conductive wires placed in a traversing sheath, an instrument placed outside the reactor for measuring the total current circulating between at least one of the conductive wires and the sheath under the action of the neutron and gamma fluxes in the core.

Abstract: This device is intended to measure the thermal power released locally in an area of the core of a nuclear reactor and comprises a conduit in the core of the reactor from the outside which contains a body which absorbs gamma radiations located at the measuring area and associated with a measuring thermocouple. A first junction of the thermocouple is placed so that it is brought to a temperature essentially representative of that of the reactor coolant and slightly affected by the gamma flux, and a second junction is placed so that it is brought to a temperature representative of that of the body which absorbs the radiations. The device comprises a supplementary thermocouple which has a first junction located near that of the measuring thermocouple and a second junction brought to a reference temperature.