Cover device for jet pumps installed in nuclear power plant vessels

A plug device for jet pumps installed in nuclear power plant vessels, comprising:

• two covers (1-2) that form two independent plug units, one fitted on the even pump, which incorporates two plugs (6), and the other one 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 a central area, wherein the three plugs (6) located on the nozzles of the odd pump are blind, and the two plugs (6) located on the nozzles of the even pump have respective fluid inlets (11) communicating through a channeled arm (13) towards an outlet (14), enabling fluid circulation during decontamination tasks, whereas three nozzles of the odd pump of each jet pump assembly are sealed;
• the arms (4) being actuated by mechanical or hydropneumatic means, applying the corresponding plug on the nozzles of the jet pump once the base (3) of the plug is supported on a mixer part of the jet pump (10), through a guide (12) centering the plug device therein, and in respective prolongations of the base (3) consisting of a lower reaction (8) serving as support both when introducing the plug in the pump and when demounting same, and in an upper reaction (9) serving to allow the closure of the plug against the nozzles of the jet pump which are located on the plug.