Patent Number: 
Section: claims

1. A hood for confinement and handling of at least two nuclear material sample tubes comprising:an external first enclosure extending along a longitudinal axis X′, comprising a cover, a bottom provided with an opening and a valve for blocking the opening and thereby sealing the external enclosure;a second enclosure forming a barrel, extending along the axis X′ and guided in rotation about the axis X′ inside the external enclosure; andat least one internal third enclosure and one internal fourth enclosure each extending along a longitudinal axis X1, X2 parallel to the axis X′ and each adapted to accommodate a nuclear material sample tube, the at least two internal enclosures being fastened to each other and guided in translation in the barrel over a stroke A0;each internal enclosure comprising within it:a holding member adapted to pick up a nuclear material sample tube;a screw-nut mechanism comprising a lead screw guided in rotation about the axis X1, X2 and a nut around the screw and to which the holding member is fastened, the mechanism being adapted to guide the latter in translation in the internal enclosure over a stroke A greater than the stroke A0; anda bottom comprising an opening opposite the holding member to allow one of the nuclear material sample tubes picked up thereby to pass through;the hood further comprising:at least one motor fixed above at least one of the said internal enclosures and inside the barrel, the at least one motor being adapted to rotate the screw of the screw-nut mechanism of each internal enclosure and therefore the nut over the stroke A;a mechanical control arranged in part above the cover of the external enclosure for manually guiding the internal enclosures in translation over the stroke A0; anda mechanical control arranged in part above the cover of the external enclosure for manually pivoting the barrel in order to bring a holding member of one of the internal enclosures opposite the opening in the bottom of the external enclosure. 2. The confinement and handling hood of claim 1, further comprising an internal fifth enclosure also extending along a longitudinal axis X3 parallel to the axis X′ and adapted to accommodate a nuclear material sample tube, the three internal enclosures fastened to one another being distributed at 120° to one another inside the barrel. 3. The confinement and handling hood of claim 1, wherein the valve for blocking the opening in the bottom of the external enclosure is further defined as a guillotine valve. 4. The confinement and handling hood of claim 1, further comprising a metal bellows fixed under each opening of an internal enclosure to provide a seal between the latter and the opening of the external enclosure on translation of the internal enclosures in the barrel. 5. The confinement and handling hood of claim 1, further comprising at least two O-rings, each accommodated at least partly in a respective peripheral groove at the top and at the bottom of an external wall of the barrel to provide a seal between the latter and the external enclosure. 6. The confinement and handling hood of claim 1, further comprising a motor fixed above each of the internal enclosures and inside the barrel being adapted to rotate the screw of the screw-nut mechanism of said internal enclosure and therefore the nut over the stroke A. 7. The confinement and handling hood of claim 1, wherein the at least one motor is further defined as an electric motor. 8. The confinement and handling hood of claim 1, wherein the holding member is mounted on the nut of the screw-nut mechanism by means of a plate guided against an internal wall of the internal enclosure by at least two lugs projecting from the plate and forming centering devices. 9. The confinement and handling hood of claim 1, wherein the mechanical control for manually guiding the internal enclosures in translation over the stroke A0 is further defined as comprising a screw-nut mechanism comprising a lead screw on a portion of a rod guided in rotation about the axis X and passing through the cover and a nut around the screw and to which the internal enclosures are fastened. 10. The confinement and handling hood of claim 1, wherein the mechanical control for manually pivoting the barrel comprises a gear mechanism consisting of a gear on a portion of a rod guided in rotation parallel to the axis X′ and passing through the cover and a toothed ring meshing internally with the gear and to which the barrel is fastened. 11. The confinement and handling hood of claim 1, wherein the holding member comprises a holding head adapted to be accommodated in an interior tube constituting a nuclear material sample tube to be picked up, the interior tube itself being adapted to be inserted in an exterior tube which cannot be held by the holding head. 12. The confinement and handling hood of claim 11, wherein the exterior tube is a measuring instrument holder tube. 13. The confinement and handling hood of claim 12, wherein the measurement instrument holder tube is adapted to accommodate at least one measurement sensor and/or a cooling system.