A replacement thermal sleeve with a flange for a reactor vessel closure head penetration adapter housing. By altering a diameter of the flange, a replacement thermal sleeve can be installed through the narrow diameter of the penetration adapter housing opening from under the reactor vessel head. The flange can be compressible or expandable or the tubular wall of the thermal sleeve can be inserted in longitudinal sections, one at a time, into an opening in the underside of the penetration head adapter and reformed within the opening when fully inserted.

A method for restraining a sleeve lining a tube passing through a nuclear reactor pressure vessel is provided. The method includes attaching in situ a radial protrusion on an external surface of the sleeve; and attaching a collar to an end of the tube and coupling the radial protrusion with the collar to retain the thermal sleeve in position.

A method for restraining a sleeve lining a tube passing through a nuclear reactor pressure vessel is provided. The method includes attaching in situ a radial protrusion on an external surface of the sleeve; and attaching a collar to an end of the tube and coupling the radial protrusion with the collar to retain the thermal sleeve in position.

A nuclear reactor vessel includes a shell (5) having a wall (9) traversed by at least one passage (11) having a central axis (C) and a valve (21) mounted in the passage (11), the valve (21) having a determined outer cross-section. The passage (11) has an inner end segment (23) that opens into the inner volume (7) and an outer end segment (25) that opens into an outer piping (13), the valve (21) being housed in the inner end segment (23). The valve (21) is capable of being extracted from the passage (11) through the inside of the vessel (1). The outer end segment (25) has at least one portion having an inner cross-section, perpendicular to the central axis (C), that is smaller than the outer cross-section of the valve (21), such that the valve (21) cannot be ejected out of the vessel (1).

A nuclear reactor vessel includes a shell (5) having a wall (9) traversed by at least one passage (11) having a central axis (C) and a valve (21) mounted in the passage (11), the valve (21) having a determined outer cross-section. The passage (11) has an inner end segment (23) that opens into the inner volume (7) and an outer end segment (25) that opens into an outer piping (13), the valve (21) being housed in the inner end segment (23). The valve (21) is capable of being extracted from the passage (11) through the inside of the vessel (1). The outer end segment (25) has at least one portion having an inner cross-section, perpendicular to the central axis (C), that is smaller than the outer cross-section of the valve (21), such that the valve (21) cannot be ejected out of the vessel (1).

The invention relates to the field of electrical engineering, and specifically to sealed inlets of electrical circuits into a sealed area of a multi-layered containment shell of a nuclear power station. This design can be used in passages through an external and an internal wall which are subject to relative mutual displacement as a consequence of a seismic phenomenon or thermal expansion of the walls and passage. The problem addressed by the present invention is that of increasing the operating reliability of a sealed cable inlet when high-voltage electrical conductors which have little bending capacity are used. The problem addressed is achieved in that the sealed cable inlet through an external and an internal wall of a containment shell of a nuclear power station comprises an embedded pipe (3) which is arranged in the internal wall (1), with an inlet section (44) of a cable (2) fixed rigidly within said pipe. A means for compensating for a relative movement between the cable (2) and the external wall (11) is mounted in the external wall (11) coaxially with respect to the pipe (3). The compensating means has a tube (19) with a bellows (24) on the external end plane (20) and with a second analogous bellows (25) which is mounted symmetrically on the opposite end plane (21) of the tube (19) at the internal surface (18) of the external wall (11). The free ends (30) and (31) of the two bellows (24) and (25) are of conical design and have internal surfaces (28) and (29) which are support elements for an outlet section (46) of the cable (2), which is arranged freely in the tube (19) with a gap (47) relative to the internal surface (49) of the tube (19). The gap (47) between the braiding (48) along the external surface of the cable (2) and the internal surface (49) of the tube (19) is selected using a design calculation. The gap (47) must not be less than the value of maximum orthogonal thermo-seismic movement in one plane of the internal wall (1) relative to the external wall (11) and change in the coaxial position of the cable (2) in the tube (19).

The invention relates to the field of electrical engineering, and specifically to sealed inlets of electrical circuits into a sealed area of a multi-layered containment shell of a nuclear power station. This design can be used in passages through an external and an internal wall which are subject to relative mutual displacement as a consequence of a seismic phenomenon or thermal expansion of the walls and passage. The problem addressed by the present invention is that of increasing the operating reliability of a sealed cable inlet when high-voltage electrical conductors which have little bending capacity are used. The problem addressed is achieved in that the sealed cable inlet through an external and an internal wall of a containment shell of a nuclear power station comprises an embedded pipe (3) which is arranged in the internal wall (1), with an inlet section (44) of a cable (2) fixed rigidly within said pipe. A means for compensating for a relative movement between the cable (2) and the external wall (11) is mounted in the external wall (11) coaxially with respect to the pipe (3). The compensating means has a tube (19) with a bellows (24) on the external end plane (20) and with a second analogous bellows (25) which is mounted symmetrically on the opposite end plane (21) of the tube (19) at the internal surface (18) of the external wall (11). The free ends (30) and (31) of the two bellows (24) and (25) are of conical design and have internal surfaces (28) and (29) which are support elements for an outlet section (46) of the cable (2), which is arranged freely in the tube (19) with a gap (47) relative to the internal surface (49) of the tube (19). The gap (47) between the braiding (48) along the external surface of the cable (2) and the internal surface (49) of the tube (19) is selected using a design calculation. The gap (47) must not be less than the value of maximum orthogonal thermo-seismic movement in one plane of the internal wall (1) relative to the external wall (11) and change in the coaxial position of the cable (2) in the tube (19).

An electrical penetration assembly for a nuclear reactor vessel, mountable in an aperture of a nuclear reactor vessel, includes a penetration body including first and second ends to be positioned, respectively, inside and outside the vessel; a sealed electrical connector providing a first seal for the electrical penetration assembly, the sealed connector insulating the penetration body at the first end; a feed-through carrier flange having a plurality of unitary electrical feed-throughs, each unitary feed-through allowing a single electrical conductor to pass therethrough, thereby ensuring continuity of the electrical connections, each unitary feed-through being individually insulated by an individual insulator providing a second seal, the unitary feed-throughs insulating the penetration body at the second end; and an anti-ejection device formed by the engagement between a narrowed portion provided at each unitary feed-through and a shoulder that is larger than the narrowed portion and provided on each of the electrical conductors.

An electrical penetration assembly for a nuclear reactor vessel, mountable in an aperture of a nuclear reactor vessel, includes a penetration body including first and second ends to be positioned, respectively, inside and outside the vessel; a sealed electrical connector providing a first seal for the electrical penetration assembly, the sealed connector insulating the penetration body at the first end; a feed-through carrier flange having a plurality of unitary electrical feed-throughs, each unitary feed-through allowing a single electrical conductor to pass therethrough, thereby ensuring continuity of the electrical connections, each unitary feed-through being individually insulated by an individual insulator providing a second seal, the unitary feed-throughs insulating the penetration body at the second end; and an anti-ejection device formed by the engagement between a narrowed portion provided at each unitary feed-through and a shoulder that is larger than the narrowed portion and provided on each of the electrical conductors.

A method for sealing an opening extending radially from an outer circumferential surface to an inner circumferential surface of a tubular object in a nuclear power plant includes inserting a stopper from outside of the outer circumferential surface through the opening into the tubular object; and actuating a fastener from the outside of the circumferential surface to force the stopper radially outward to seal the opening. A mechanical seal assembly for plugging an opening in a tubular object by contacting an inner circumferential surface of the tubular object includes a stopper configured for insertion into an interior of the tubular object for plugging the opening. The stopper includes a surface configured for matching the inner circumferential surface of the tubular object. The mechanical seal assembly also includes a fastener passing through a hole in the stopper such that the fastener is actuatable from outside of the tubular object to force the surface of the stopper against the inner circumferential surface of the tubular object.