Abstract

The invention relates to a plug device for jet pumps installed in nuclear power plant vessels, which comprises two covers (1-2) that form two independent plug units, one fitted on the even pump, which incorporates two plugs (6), and the other on the odd pump of each jet pump assembly, which incorporates three plugs (6), both mounted on a common base (3) at the end of respective arms (4), articulated in the central area, which are actuated by mechanical or hydropneumatic means. The plugs may be blind, in which case they are used to seal the five outlets of the nozzle of the jet pump, or channeled, being used to close the decontamination circuit of the recirculation loops, preventing the cleaning solution from being dispersed in the reactor.