Abstract: After a nuclear reactor has been stopped and allowed to cool down following a period of operation, action is taken in a pool of the nuclear reactor on at least one guide tube of the activated upper internal equipment of the nuclear reactor to enlarge (21b, 21c) guide channels (16b, 16c) of the guide tube (8) in at least one continuous guidance zone. The enlargement is preferably performed by machining discontinuous cavities along the length of the guide channel (16b, 16c). Enlargement is preferably performed on the guide tube (8) in place within the upper internal equipment that has been placed on a storage stand in the reactor pool.

Abstract: After a nuclear reactor has been stopped and allowed to cool down following a period of operation, action is taken in a pool of the nuclear reactor on at least one guide tube of the activated upper internal equipment of the nuclear reactor to enlarge (21b, 21c) guide channels (16b, 16c) of the guide tube (8) in at least one continuous guidance zone. The enlargement is preferably performed by machining discontinuous cavities along the length of the guide channel (16b, 16c). Enlargement is preferably performed on the guide tube (8) in place within the upper internal equipment that has been placed on a storage stand in the reactor pool.

Abstract: A device for measuring the force exerted by a spring of a supporting grid on a fuel rod passing through the grid has an elongate body connected by two flexible blades that are parallel to the long direction to two respective beams insertable in a cell. At least one of the beams carries a force sensor designed to be pressed against the spring. A unit is slidable in the body along the body between a position in which it moves the beams apart while keeping them parallel to give them a spacing that corresponds to the nominal diameter of a fuel rod, and a position in which it allows the flexible blades to move the beams towards each other. The unit is movable at will between the two positions.

Abstract: A device for guiding a nuclear reactor control cluster comprises guide tubes provided in the fuel assemblies, and in the upper internals, a tubular casing having an upper closure with a hole for passing the cluster drive shaft, horizontal guide plates spaced apart along the casing and cut out so as to let the spider pass and to guide the elements of the cluster, and split tubes for guiding individual elements for protecting the elements from the action of the coolant. Openings are provided immediately below the plates at the top of each internal between the guide plates. The guide tubes in a lower portion of the casing are devoid of openings other than to a slit for passage of a spider carrying the cluster.

Abstract: Bicomponent filaments are produced by separately melting the polymers, and passing the sparingly cross-linked polybutylene terephthalate through a plurality of channels in a distribution plate in the form of a jet or stream, which is then introduced into a cavity between the distribution plate and the spinneret plate of the spinneret assembly. The molten polyethylene terephthalate is separately introduced into the cavity between these plates, wherein it surrounds and envelopes the jets of sparingly cross-linked polybutylene terephthalate. The jets of polybutylene terephthalate, and accompanying polyethylene terephthalate, then pass through bores in the spinneret plate, which are of larger diameter than the aforesaid channels, with each bore associated with a corresponding channel. The axis of each bore is displaced from the axis of the corresponding channel at least the distance equal to the differences between the radius of the bore and the radius of the channel.

Abstract: Bicomponent polyester fibers exhibiting a hand similar to wool, a crimp contraction less than 60%, and a crimp frequency of at least 7 half-waves per centimeter, and the process for producing the same, are disclosed.These crimped bicomponent fibers are useful in the textile field, particularly to at least partially replace the wool in polyester/wool blends.

Abstract: Side-by-side bicomponent polyester filaments, and process for making same, are disclosed, wherein the filaments are of polyethylene terephthalate and polybutylene terephthalate, with the polybutylene terephthalate being sparingly cross-linked by at least about 0.20 mole per cent of cross-linking agent. The sparingly cross-linked polybutylene terephthalate has a melted state viscosity VF of at least about 2000 poises at 260.degree. C. The polyethylene terephthalate partly envelopes the sparingly cross-linked polybutylene terephthalate, in cross-section, so as to cover at least about 45% of the periphery of the sparingly cross-linked polybutylene terephthalate.

Abstract: Bicomponent polyester fibers exhibiting a hand similar to wool, a crimp contraction less than 60%, and a crimp frequency of at least 7 half-waves per centimeter, and the process for producing the same, are disclosed.These crimped bicomponent fibers are useful in the textile field, particularly to at least partially replace the wool in polyester/wool blends.

Abstract: This invention provides yarns of randomly crimped filaments which are associated together into a substantially cylindrical yarn. The filaments are made by extruding two different synthetic organic polymers simultaneously through the same elongated orifice and the polymers are fed to different orifices in different proportions or at different angles with respect to the axes of the orifices so that in some of the filaments the interface between the two polymer layers is along or parallel to the smaller axis of the cross-section thereof while the interface of other filaments is along or parallel to the larger axis.

Abstract: Bicomponent polyester filaments are disclosed, wherein the filaments are made of at least two different, substantially unmixed components, each present in an amount of at least 20% by weight of the total filament, one component being polyethylene terephthalate and the other component being polybutylene terephthalate which has been sparingly crosslinked with trimethylolpropane.The bicomponent polyester filaments of the present invention have excellent physical properties and especially improved permanency of crimping. The filaments may be used to manufacture woven and knit materials, and are especially useful in the manufacture of hosiery, wherein the resulting hosiery articles have excellent wear properties.