Patent Number: 
Section: claims

1. An electrical penetration assembly for a nuclear reactor vessel that can be mounted in an aperture of a nuclear reactor vessel, said electrical penetration assembly comprising:a penetration body comprising:a first end configured to be positioned inside the vessel;a second end configured to be positioned outside the vessel;a sealed electrical connector forming a first seal for the electrical penetration assembly, said sealed electrical connector hermetically sealing the penetration body at the first end;a feed-through carrier flange at the second end of the penetration body comprising a plurality of unitary electrical feed-throughs, each unitary electrical feed-through allowing a single electrical conductor to pass therethrough thereby ensuring the continuity of the electrical connections, each unitary electrical feed-through having a narrowed portion at an outer end and being individually insulated by an individual insulator forming a second seal for the electrical penetration assembly, said unitary electrical feed-throughs hermetically sealing the penetration body at the second end, each of the electrical conductors having a shoulder provided thereon that is larger in size than the narrowed portion, and said individual insulator being provided between the narrowed portion and the shoulder;an anti-ejection device formed by the engagement between the narrowed portion provided at each unitary electrical feed-through and the shoulder that is provided on each of the electrical conductors of said unitary feed-throughs. 2. The electrical penetration assembly for a nuclear reactor vessel according to claim 1, further comprising means for making the electrical penetration assembly integral, in a leak-tight manner, with the outside of said reactor vessel. 3. The electrical penetration assembly for a nuclear reactor vessel according to claim 1, wherein said individual insulators are insulators made of ceramic or prestressed vitroceramic. 4. The electrical penetration assembly for a nuclear reactor vessel according to claim 3, wherein said sealed electrical connector is an electrical connector having an insulator made of ceramic or an insulator made of prestressed vitroceramic. 5. The electrical penetration assembly for a nuclear reactor vessel according to claim 4, wherein the material of the insulator of the sealed electrical connector is different from the material forming the individual insulators. 6. The electrical penetration assembly for a nuclear reactor vessel according to claim 1, further comprising means for detecting a leak-tightness failure of the unitary feed-throughs. 7. The electrical penetration assembly for a nuclear reactor vessel according to claim 6, wherein the electrical penetration body is pressurised by an inert gas and wherein the means for detecting a leak-tightness failure are formed by a detection device detecting an increase in pressure downstream of the unitary feed-throughs. 8. The electrical penetration assembly for a nuclear reactor vessel according to claim 1, wherein the penetration body comprises, at the first end thereof, at least one rigid part at the aperture and one flexible part adjacent to the sealed electrical connector that is capable of deforming at least along one direction. 9. The electrical penetration assembly for a nuclear reactor vessel according to claim 1, wherein the narrowed portion of each of the unitary electrical feed-throughs and the shoulder are further configured for limiting a leakage rate of liquid upon engagement, in the event of failure of the sealed electrical connector combined with the failure of at least one individual insulator. 10. The electrical penetration assembly for a nuclear reactor vessel according to claim 1, wherein the electrical penetration assembly further comprises a plurality of unitary ducts provided inside the penetration body between the first end and the second end thereof, each unitary duct being suitable for allowing a single electrical conductor to pass therethrough for going through said penetration body. 11. The electrical penetration assembly for a nuclear reactor vessel according to claim 1, wherein the second end of the penetration body further comprises a leakage and connection detection cell connected to an outer end of the feed-through carrier flange and a sealed connector provided at the second end of the penetration body. 12. A nuclear reactor vessel comprising at least one electrical feed-through according to claim 1. 13. The a nuclear reactor vessel according to claim 12, further wherein the feed-through carrier flange is part of an end plate arranged at the second end of the penetration body, and wherein the end plate engages the nuclear reactor vessel via fastening elements and at least one ring joint. 14. A nuclear reactor comprising a vessel according to claim 12. 15. The nuclear reactor according to claim 14, wherein said nuclear reactor is an integrated reactor or a small modular reactor.