Abstract: A steam generator for nuclear power plant applications. U-shaped heat exchanger tubes within said steam generator are provided with compliant antivibration bars at the U-shaped portion of the tubes. Flexible plates located at opposite sides of the antivibration bars are placed in contact with the opposite sides of the rows of tubes. Support ribs spaced along the length of the compliant bars limit the deflection of the flexible plates and establish the effective length of the flexible plates. The ribs in successive columns of antivibration bars are located between the ribs of the bars of each preceding and following row.

Abstract: A plumb nozzle for a nuclear fuel assembly having asymmetric loading of the fuel mass comprising a raised protuberance on the handling tool gripper finger engaging surface of the nozzle to compensate for skewing caused by the asymmetric fuel loading. The protuberance is positioned to be engaged by a gripper finger during handling, loading, or unloading of the fuel assemblies and extends downwardly a predetermined distance with respect to the other gripper finger engaging surfaces so that the fuel assembly hangs plumb.

Abstract: A quick opening hatch for use on a transfer tube of a nuclear reactor plant that is adapted to replace the conventional hatch on the transfer tube. A locking ring is provided with a plurality of screw openings that is adapted for connection to the transfer tube, and a hatch cover fitably received within the locking ring for closing-off the transfer tube. To lock the cover to the ring, latches are movably connected with the cover for locking engagement with the locking ring, and a sprocket with a plurality of crank arms is movably connected with the cover and the latches for movement thereof into locking engagement with a latch housing on the locking ring for locking the cover to the ring and out of engagement with the latch housing for releasing the cover from the locking ring so as to permit removal of the hatch cover from the locking ring to provide access to the transfer tube.

Abstract: Apparatus for baffling the flow of reactor coolant fluid into and about the core of a nuclear reactor. The apparatus includes a plurality of longitudinally aligned baffle plates with mating surfaces that allow longitudinal growth with temperature increases while alleviating both leakage through the aligned plates and stresses on the components supporting the plates.

Abstract: Apparatus for aligning a nuclear reactor vessel, vessel head, core barrel and upper support structure. The apparatus includes mating extensions and receptacles that not only align and assure proper lateral orientation and stability of the reactor components during operation, but also provide alignment of the vessel head and upper support structure when removed from the reactor simultaneously.

Abstract: An emergency core cooling system for a nuclear reactor which preferably is supplemental to the main emergency core cooling system incorporated in the reactor at the time of construction. Under circumstances of a rupture in the reactor primary coolant piping and consequent drop in reactor coolant pressure, emergency supplemental coolant is supplied from tanks or accumulators through check valves into the head closure plenum area. From there, the coolant is distributed downwardly through hollow support columns and through control rod guide thimbles to the top of the fuel assemblies which comprise the reactor core. The pressure and flow of the emergency supplemental coolant is sufficiently great to overcome the normal upward flow of primary coolant through the core, the result being that the supplemental coolant causes collapse of bubbles otherwise generated by the heat producing fuel rods thereby permitting the supplemental coolant to effectively and efficiently carry away heat generated in the core.