Patent Number: 
Section: claims

1. A pressurizer for a pressurized water nuclear power plant, comprising:an upper cap equipped with a nozzle, the nozzle being covered, on an inner face of the nozzle, with a coating;an end piece connected to the nozzle through a first weld;a thermal protective sleeve;a support piece; anda fixing arrangement configured to fix the thermal protective sleeve to the support piece, the fixing arrangement being used to remove the thermal protective sleeve without cutting the first weld such that the first weld is maintained for inspection, the thermal protective sleeve being removed without cutting the end piece,wherein the support piece is fixed on the coating, the fixing arrangement including an external thread on the thermal protective sleeve and an internal thread on the support piece, the external thread being screwed on the internal thread, andwherein the thermal protective sleeve protects the first weld disposed inside the nozzle and is mounted in such a manner that the sleeve can be removed from inside the pressurizer using the fixing arrangement. 2. The pressurizer according to claim 1, wherein the sleeve includes, on an external surface of the sleeve, a plurality of antivibration pads, the pads being regularly distributed. 3. The pressurizer according to claim 1, wherein the support piece presents a further external thread, and wherein the pressurizer further comprising: a spray head screwed on the further external thread. 4. The pressurizer according to claim 3, wherein a lower end of the sleeve is such that, when the sleeve is in place, the lower end is positioned between the support piece and the spray head. 5. The pressurizer according to claim 3, further comprising: an arrangement locking in rotation the spray head. 6. The pressurizer according to claim 5, wherein the arrangement is fixed to the support piece through a second weld. 7. A method for removing a thermal protective sleeve of a pressurizer, comprising:removing a second weld between an arrangement of the pressurizer and a support piece of the pressurizer, the pressurizer further including an upper cap equipped with a nozzle, an end piece connected to the nozzle through a first weld, the thermal protective sleeve protecting the first weld disposed inside the nozzle, and a fixing arrangement configured to fix the thermal protective sleeve to the support piece, the fixing arrangement being used to remove the thermal protective sleeve without cutting the first weld such that the first weld is maintained for inspection, the thermal protective sleeve being removed without cutting the end piece, wherein the thermal protective sleeve is removed from inside the pressurizer using the fixing arrangement, the nozzle being covered, on an inner face of the nozzle, with a coating, the support piece being fixed on the coating, the fixing arrangement including an external thread on the thermal protective sleeve and an internal thread on the support piece, the external thread being screwed on the internal thread, the support piece presenting a further external thread, the pressurizer further including a spray head screwed on the further external thread, a lower end of the protective sleeve is such that, when the protective sleeve is in place, the lower end is positioned between the support piece and the spray head, the arrangement locking in rotation the spray head and being fixed to the support piece through the second weld;removing the arrangement;unscrewing the spray head; andunscrewing the thermal sleeve.