| 摘要 |
PROBLEM TO BE SOLVED: To provide a neutron detection apparatus capable of preventing a solid substance from being generated inside a thimble guide tube.SOLUTION: A neutron detection apparatus includes: a neutron detector 19 for detecting distribution of neutron fluxes in an in-core 30a of a reactor 30; a thimble guide tube 18 into which the neutron detector 19 is inserted from an outside 30b of the reactor to the in-core 30a to be installed; a drive device 1, connected to the thimble guide tube 18, for inserting/extracting the neutron detector 19 into/from the thimble guide tube 18; a vacuum unit 10 for controlling a vacuum state in the thimble guide tube 18; a supply unit 11 for supplying carbon dioxide; a gas purge unit 9, connected to the supply unit 11, for subjecting the thimble guide tube 18 to gas purge with the carbon dioxide; a gate valve 5, formed between the thimble guide tube 18 and the drive device 1, for conducting opening/closing; and a control device 17 for controlling the gate valve 5, the drive device 1, the vacuum unit 10, the supply unit 11, and the gas purge unit 9. |
