Anti-rotation arrangement for thermal sleeves

1. A device for resisting rotation of a thermal sleeve about a central axis thereof relative to a head penetration adapter in a nuclear reactor, wherein the device comprises:

a first structure provided on or in the thermal sleeve; and

a second structure provided on or in the head penetration adapter, wherein the first structure and the second structure are configured to be operably engaged to resist rotation of the thermal sleeve about the central axis relative to the head penetration adapter while allowing axial movement of the thermal sleeve relative to the head penetration adapter, wherein the first structure comprises a first ring configured to be coupled to the thermal sleeve, wherein the first ring comprises a plurality of rod members extending therefrom, wherein each rod member extends along a rod axis that is parallel to the central axis of the thermal sleeve when the first structure is coupled to the thermal sleeve, wherein the second structure comprises a second ring configured to be coupled to the head penetration adapter, wherein the second ring comprises a plurality of thru-holes formed therein, wherein each thru-hole defines a thru-hole axis that is parallel to the central axis when the second ring is coupled to the head penetration adapter, and wherein each rod member of the first ring is configured to slidingly engage a corresponding thru-hole of the second ring.

2. The device of claim 1 , wherein the first ring is formed of a stainless steel material, and wherein the second ring is formed from an alloy.

3. The device of claim 1 , wherein the second ring comprises a female threaded portion which is configured to engage a cooperatively male threaded portion of the head penetration adapter.

4. The device of claim 1 , wherein the second ring comprises an inner stepped portion configured to receive a lower end of the head penetration adapter.

5. The device of claim 1 , wherein the second ring comprises a first segment and a second segment, and wherein the first segment is couplable to the second segment to attach the second ring to the head penetration adapter.

6. The device of claim 1 , wherein the plurality of rod members consists of two rod members.

7. The device of claim 1 , wherein the first ring comprises a first segment and a second segment, and wherein the first segment is couplable to the second segment to attach the first ring to the thermal sleeve.

8. The device of claim 7 , wherein the first segment and the second segment each include interlocking portions, and wherein the first segment and the second segment are couplable together via the interlocking portions.

9. The device of claim 1 , wherein the first ring comprises a first piece and a second piece separate from the first piece, wherein the first piece includes one rod member of the plurality of rod members, and wherein the second piece includes another rod member of the plurality of rod members.

10. The device of claim 1 , wherein each rod member has a non-circular cross-section and wherein each thru-hole has a correspondingly-shaped non-circular cross-section.

11. The device of claim 1 , wherein one of the first ring and the second ring comprises a mechanical clamp configured to mechanically couple one of the first ring and the second ring to the thermal sleeve or the head penetration adapter.

12. The device of claim 1 , wherein the first ring comprises a split clamp configured to be coupled to the thermal sleeve, and wherein the split clamp comprises two segments which are configured to be coupled together via threaded fasteners.

13. The device of claim 12 , wherein one of the two segments includes pockets formed therein for engagement by crimped portions of one of the threaded fasteners.

14. A device for resisting rotation of a thermal sleeve about a central axis thereof relative to a head penetration adapter in a nuclear reactor, wherein the device comprises:

a first structure provided on or in the thermal sleeve; and

a second structure provided on or in the head penetration adapter, wherein the first structure and the second structure are configured to be operably engaged to resist rotation of the thermal sleeve about the central axis relative to the head penetration adapter while allowing axial movement of the thermal sleeve relative to the head penetration adapter, wherein the first structure comprises a split clamp configured to be coupled to the thermal sleeve, wherein the split clamp comprises two segments which are configured to be coupled together via threaded fasteners, wherein one of the two segments comprises a pair of rods extending therefrom, wherein the second structure comprises axial slots defined in the head penetration adapter, wherein the axial slots extend longitudinally along a length of the head penetration adapter, and wherein each rod is configured to engage a respective axial slot in the head penetration adapter.

15. A device for resisting rotation of a thermal sleeve about a central axis thereof relative to a head penetration adapter in a nuclear reactor, wherein the device comprises:

a first structure provided on or in the thermal sleeve; and

a second structure provided on or in the head penetration adapter, wherein the first structure and the second structure are configured to be operably engaged to resist rotation of the thermal sleeve about the central axis relative to the head penetration adapter while allowing axial movement of the thermal sleeve relative to the head penetration adapter, wherein the second structure comprises a body portion configured to be coupled to the head penetration adapter, wherein the body portion includes a plurality of apertures oriented orthogonal to the central axis, wherein each aperture comprises a slidable member positioned therein, wherein the first structure comprises a plurality of slots defined in the thermal sleeve, and wherein each slidable member is configured to engage a corresponding slot in the thermal sleeve.