Installation and method for producing activated irradiation targets in an instrumentation tube system of a nuclear reactor

A decay station configured for receiving irradiation targets from a structure of a core of a nuclear reactor in a predetermined linear order, the decay station comprising:

• a housing comprising a radiation shielding configured for shielding an environment of the decay station from radiation emitted by the irradiation targets contained in the decay station, the housing delimiting a decay conduit intended for containing the irradiation targets in the predetermined linear order, the decay conduit comprising:
• a decay conduit inlet configured to be connected to the structure of the core of the nuclear reactor for receiving the irradiation targets therefrom, and
• a decay conduit outlet configured to be connected to an irradiation target discharge system for discharging the irradiation targets from the decay station;
• an inlet distributor located at the decay conduit inlet and configured for releasing only a predetermined amount of the irradiation targets at a time from the decay station towards the structure of the core of the nuclear reactor, the inlet distributor being configured for releasing the irradiation targets closest to the decay conduit inlet, while retaining a remainder of the irradiation targets in the decay conduit;
• an inlet counter configured for counting a number of the irradiation targets entering or exiting the decay conduit through the decay conduit inlet, the inlet counter being located at the decay conduit inlet;
• and
• an outlet radiation detector configured for measuring the radiation emitted by an irradiation target located at the decay conduit outlet;
• the inlet distributor successively comprising, in a direction from the decay conduit inlet toward the decay conduit outlet:
• a lock element displaceable between a locking position, in which the lock element blocks movement of the irradiation targets out of the decay conduit through the decay conduit inlet and a release position, in which the lock element allows the predetermined amount of the irradiation targets out of the decay conduit through the decay conduit inlet;
• and
• a retainer displaceable between a retracted position, in which the retainer allows passage of the irradiation targets, and an extended position, in which the retainer extends at least partially into the decay conduit, the retainer being configured for abutting against an irradiation target in the extended position so as to block the movement of the irradiation target towards the decay conduit inlet,
• the inlet distributor further comprising:
• a first actuator configured for displacing the lock element between the locking position and the release position;
• and
• a second actuator configured for displacing the retainer between the extended position and the retracted position.