Abstract: A method for replacing bolts on core components of nuclear reactors includes machining away a bolt fastened at an installation site in a core component as well as the entire fastening of the bolt with an electroerosion machine. Machined-away bolt material is removed and caught with a filter. The bolt is then ejected from the core component with a closed force system. The installation site of the bolt is remachined with an accurate fit and a new bolt is subsequently inserted. An apparatus for replacing bolts on core components of nuclear reactors includes rails. An auxiliary platform is supported on the rails on both sides of a reactor pressure vessel. An auxiliary crane is disposed on the auxiliary platform and adjustable transverse to the rails. A tool carrier is guided on the auxiliary platform and suspended from the auxiliary crane. A tool is disposed on the tool carrier for replacing bolts on core components.

Abstract: Method of producing a core baffle with a plurality of horizontally disposed, parallel profile-rib rings for enclosing the fuel assemblies of a pressurized-water reactor, the profile-rib rings being formed with respective cutouts having a polygonal contour corresponding to that of the reactor core and with baffle plates secured vertically to the profile-rib rings and forming a casing matching the contours of the cutouts, which includes fastening to the profile-rib rings, by welding, one end of a plurality of ribs having a height corresponding to a mutual spacing of the profile-rib rings; successively welding the profile-rib rings to one another by the respective ribs thereof into a cage; assembling baffle plates bent partly into profile sections into the form of casing by bracing the plates against the cage; successively welding the baffle plates to the profile-rib rings of the cage; and welding the baffle plates to one another into a tight casing.

Abstract: Apparatus for core-barrel crash protection and conduction of coolant in a nuclear reactor pressure vessel having a spherical bottom, including a core support structure having a core barrel and being disposed within the pressure vessel, including coolant collecting means disposed below the core support structure and supported on the spherical bottom for equalizing coolant flow, the collecting means being in the form of a substantially hollow cylindrically walled perforated barrel having coolant passage openings formed therein, the spherical bottom having an annular bracket and a central bracket rigid thereto, the perforated barrel having a lower rim disposed on the annular bracket and a central support piece disposed on the central bracket, and means for pressing the lower rim against the annular bracket, the pressing means including a strut system connecting the central support piece to the cylindrical wall of the perforated barrel and detachable connecting means for clamping the central support piece to the

Abstract: Safety device for preventing unscrewing of cylinder head screws fastening two structural members together, one of the structural members having receiving bores formed therein, the screws having heads disposed in said receiving bores and being formed with inner polygonal cutouts, the screws extending through the one structural member and being anchored in the other structural member, includes circular grooves cut into the one structural member at the receiving bores, plastically deformable ring collars disposed in the circular grooves and spaced from the screw heads so as to form annular gaps therebetween, at least two arcuate recesses formed at equal distances from one another about the periphery of the screw heads, the ring collars having a first set of portions thereof pushable into the arcuate recesses in tightened condition of the screws.