Abstract: An eddy current flaw detecting apparatus comprises a pair of detection coils each connected in adjoining arms of flaw detecting bridge circuit, the planes containing the pair of coils are arranged in parallel and inclined to the axis of a fuel clad pipe being examined at an inclination angle between 75.degree. and 85.degree. and an arrangement for rotating the fuel clad pipe relative to the pair of detection coils, when a flaw is detected while moving the fuel clad pipe relative to the pair of detection coils, to obtain a characteristic curve between a flaw signal output and turning angle in order to determine direction of the flaw, such as circumferential and axial, in comparison with characteristic curves between a flaw signal output and turning angle obtained in advance with respect to standard flaw testing pieces.

Abstract: An apparatus for separating solid matters having a rotor of a double-basket construction consisting of a centrifugal filtering basket which is secured in a basket which effects the separation relying upon the difference in specific gravity. A pipe is so arranged as to supply the liquid to be treated into the centrifugal filtering basket, and scoop pipes are arrayed near the side surfaces of the two baskets.

Abstract: A sodium-handling apparatus is disassembled and repaired by (1) contacting an inert gas with the sodium-contacting surfaces within the apparatus after discharge of sodium from the apparatus, thereby solidifying the deposited sodium, (2) flushing the inert gas with a reacting gas capable of reacting with sodium, capable of being dissolved in sodium and capable of forming a weak alkali therein, thereby forming a solid film of a neutral salt on surfaces of the deposited sodium by reaction of sodium with the reacting gas, (3) discharging the reacting gas from the apparatus, (4) disassembling and repairing the apparatus in the atmosphere, and then (5) continuing operation of the apparatus while the solid film is being retained on the surfaces of the apparatus.