Patent Number: 
Section: claims

1. A method of inspecting, performing maintenance on, or repairing a nuclear reactor with an annular space between a reactor pressure vessel and a core shroud, the method comprising:operatively connecting a fixing device, a first track, an arc-shaped arm including one or more second tracks, and an effector to form an apparatus;inserting the apparatus into the annular space between the reactor pressure vessel and the core shroud of the reactor;attaching the fixing device to an inner wall of the reactor pressure vessel; andoperating the apparatus;wherein at least one of the one or more second tracks includes at least three track sections, each of the at least three track sections being arc-shaped,wherein the arm has a contracted length,wherein the arm has an expanded length, andwherein the expanded length is greater than two times the contracted length. 2. A method of operating a nuclear reactor with an annular space between a reactor pressure vessel and a core shroud, the method comprising:shutting down the reactor;inspecting, performing maintenance on, or repairing the reactor;removing the apparatus from the annular space: andstarting up the reactor;wherein the reactor is inspected, maintenance is performed on the reactor, or the reactor is repaired according to the method of claim 1. 3. The method of claim 1, wherein the first track comprises one or more motors configured to move the arm relative to the first track. 4. The method of claim 1, wherein the first track comprises one or more motors configured to move the arm along the first track. 5. The method of claim 1, wherein the first track comprises one or more motors configured to rotate the arm relative to the first track. 6. The method of claim 1, wherein the arm is operatively connected to the first track. 7. The method of claim 6, wherein the first track comprises one or more motors configured to move the arm relative to the operative connection of the arm to the first track. 8. The method of claim 6, wherein the first track comprises first, second, and third motors,wherein the first motor is configured to move the arm relative to the operative connection of the arm to the first track,wherein the second motor is configured to move the arm along the first track, andwherein the third motor is configured to rotate the arm relative to the first track. 9. The method of claim 1, wherein the arm is configured to move relative to the first track. 10. The method of claim 1, wherein the arm is configured to move along the first track. 11. The method of claim 6, wherein the arm is configured to move relative to the operative connection of the arm to the first track. 12. The method of claim 1, wherein the arm is configured to rotate relative to the first track. 13. The method of claim 1, wherein,the at least three track sections are configured to contract the arm to the contracted length,the at least three track sections are configured to expand the arm to the expanded length,the arm maintains the arc-shape throughout the expansion and contraction of the arm. 14. The method of claim 1, wherein the fixing device is operatively connected to the first track. 15. The method of claim 1, wherein,the fixing device comprises one or more scissor jacks,the scissor jacks configured to expand and contract, to move the first and second tracks toward and way from the core shroud, respectively. 16. The method of claim 1, wherein the effector is operatively connected to the arm. 17. The method of claim 16, wherein the operative connection of the effector to the arm comprises a bracket. 18. The method of claim 1, wherein the effector comprises one or more sensors. 19. The method of claim 1, wherein the effector comprises one or more tools. 20. A method of inspecting, performing maintenance on, or repairing a nuclear reactor with an annular space between a reactor pressure vessel and a core shroud, the method comprising:operatively connecting a fixing device, a first track, an arc-shaped arm including one or more second tracks, and an effector to form an apparatus;inserting the apparatus into the annular space between the reactor pressure vessel and the core shroud of the reactor;attaching the fixing device to an inner wall of the reactor pressure vessel; andoperating the apparatus;wherein at least one of the one or more second tracks includes at least three track sections, each of the at least three track sections being arc-shaped, andwherein the first track includes one or more motors configured to move the arm relative to the first track. 21. A method of operating a nuclear reactor with an annular space between a reactor pressure vessel and a core shroud, the method comprising:shutting down the reactor;inspecting, performing maintenance on, or repairing the reactor;removing the apparatus from the annular space; andstarting up the reactor;wherein the reactor is inspected, maintenance is performed on the reactor, or the reactor is repaired according to the method of claim 20. 22. The method of claim 20, wherein the first track comprises one or more motors configured to move the arm along the first track. 23. The method of claim 20, wherein the first track comprises one or more motors configured to rotate the arm relative to the first track. 24. The method of claim 20, wherein the arm is operatively connected to the first track. 25. The method of claim 24, wherein the first track comprises one or more motors configured to move the arm relative to the operative connection of the arm to the first track. 26. The method of claim 24, wherein the first track comprises first, second, and third motors,wherein the first motor is configured to move the arm relative to the operative connection of the arm to the first track,wherein the second motor is configured to move the arm along the first track, andwherein the third motor is configured to rotate the arm relative to the first track. 27. The method of claim 20, wherein,the at least three track sections are configured to contract the arm to the contracted length,the at least three track sections are configured to expand the arm to the expanded length,the arm maintains the arc-shape throughout the expansion and contraction of the arm. 28. The method of claim 20, wherein the fixing device is operatively connected to the first track. 29. The method of claim 20, wherein the effector is operatively connected to the arm. 30. The method of claim 20, wherein the effector comprises one or more sensors. 31. The method of claim 20, wherein the effector comprises one or more tools. 32. The method of claim 1, wherein the core shroud is located within the reactor pressure vessel.