Apparatus for the determination of the distribution of the neutron flux in the cores of reactors.

摘要

866,514. Nuclear reactors. A.E.I.-JOHN THOMPSON NUCLEAR ENERGY CO. Ltd. Oct. 8, 1958 [Oct. 18, 1957], No. 32617/57 Class 39(4). The neutron flux density distribution in a nuclear reactor is measured by measuring the activity induced in a wire or rod 5 (e.g. of tungsten) lowered into and then withdrawn from a channel in the reactor core. The error caused by the finite time of insertion and removal of the wire is allowed for by modifying the output of the detector which measures the activity in accordance with the distance along the wire of the detector. The modifier may be a graded or cam-driven variable resistor driven by the movement of the wire. Measurement is carried out by lowering the wire at 5SP1/SP past the detector 23 (e.g. an ionisation chamber) in a well in the reactor shield.