JPH0555839B

PURPOSE:To facilitate loading operation and to improve a plant working efficiency by loading the title tube which is held previously mounted with a dry tube, detector and cable into a reactor core. CONSTITUTION:A step part 105 as a supporting mechanism to support a dry tube 22 from below is formed to an upper cap 102 of a nose cap 101 and a protective cover 107 as a protective device to protect a connector 43 is installed in a lower cap 103. The nose cap 101 is screwed to the upper and lower caps 102, 103. The outside circumferential part of the upper and lower caps 102, 103 are chamfered. A set-screw 111 which prevents falling of the protective cover 107 is provided on the top end part of the protective cover 107 in the lower cap 103. The neutron flux measuring tube which is held previously mounted with the dry tube, detector and cable is thereby loaded into the reactor and the loading operation is facilitated.