Abstract: A handling method for a natural circulation boiling water reactor having a chimney having cylindrical chimney shell disposed above a core in a reactor pressure vessel, a plurality of square tubes disposed in the chimney shell, and a grid support plate with grid holes supporting and in communication with a lower end portion of the square tubes so that adjacent square tubes are disposed at an interval which exceeds the width of one square tube between them. The method includes steps shifting predetermined ones of the square tubes to the interval between the square tubes, and performing maintenance and inspection of members around a core via the grid holes which appear at positions from which the predetermined square tubes are taken out due to the shift of the predetermined square tubes.

Abstract: A control rod/fuel support grapple is provided which is capable of pulling up simultaneously a control rod and a fuel support from a reactor and also uncoupling the control rod and control rod drive mechanism. The control rod/fuel support grapple comprises a control rod holding unit for holding a control rod's hoist handle, a fuel support holding unit for holding a fuel support, and a coupling releasing unit or uncoupling the control rod and the control rod drive mechanism, coupled by virtue of a spud coupling. These three units are attached to a main body frame which is lowered into a reactor pressure vessel.

Abstract: A skills based telephone call distribution system is disclosed. The system determines the informational needs of an incoming caller and defines a set of skills an agent should possess to serve the caller. A search is performed for an available agent possessing the skill set. Upon the search failing to locate an available agent possessing the skill set, the amount of time the caller may expect to wait therefor is estimated. The estimated time is compared to a maximum waiting time. If the estimated time is greater than the maximum waiting time, then the skill set is redefined to include a greater number of agents who may serve the caller. A new search is performed for an available agent possessing the redefined skill set.

Abstract: A process is provided for the long term shutdown of a high temperature nuclear reactor comprised of a pile of spherical fuel elements in a core by means of a neutron absorbing absorber material wherein the absorber material consisting of spherical absorber elements is introduced in the core of spherical fuel elements in the form of a column, but wherein the intermixing of the absorber material with the fuel elements is prevented. An apparatus for practicing the process is also provided comprised of a graphite side reflector concentrically surrounding a circular cylindrical core filled with a pile of spherical fuel elements of a high temperature nuclear reactor, into which at least two nose shaped projections distributed uniformly about the circumference radially project, with each of the projections comprising a vertical cavity to contain the absorber material. The vertical cavity is located in the vicinity of the core in the area of the frontal side facing the core of each projection.

Abstract: A multi-region reactor core pebble bed high temperature gas reactor comprises a pebble bed reactor core housed within a pressure vessel and charged with spherical fuel. The reactor core is surrounded by a reflector wall comprising a partition wall which partitions the reactor core into a plurality of reactor core sub-regions. The reflector wall comprises a plurality of layers of reflector blocks, adjacent blocks of a layer being secured against one another by removable tapered keys wedged therein between.

Abstract: The invention concerns a nuclear power plant located in an underground cavity, with a small high-temperature reactor which, together with a heat exchanger apparatus, is housed in a steel reactor pressure vessel. The reactor core comprises spherical operating elements which pass through the reactor several times. In order to provide unimpaired access to the components of the primary loop from above, the loading installation of the small high-temperature reactor is designed in a specific manner. It comprises a section located in a loading space under the reactor pressure vessel including a discharge device and a conveyor device. An addition device for fresh operating elements and a collector vessel for used operating elements are arranged either outside the underground cavity or, in the alternative, in the loading space.

Abstract: A medium power, high temperature pebble bed nuclear reactor, which includes a means for introduction and withdrawal of operating elements. The installation is provided in such a way that it can be more economically built and operated. The installation includes several input stations above a prestressed concrete pressure vessel, and charging hatch blocks positioned on top of the prestressed concrete pressure vessel. The blocks include selectors through which the pebble-shaped operating elements, after traversing helical and meandering charging conduits, reach into the reactor core. The selectors and charging conduits are installed within armored ducts which penetrate the prestressed concrete pressure vessel. Similar armored ducts are provided for exit ducts for withdrawal of pebbles from the core, and a first common exit hatch block is connected to the exit ducts. The block is arranged within foundation walls which support the prestressed concrete pressure vessel.

Abstract: Grill gates respectively formed by oppositely moving, interfitting rod combs with gaps between the rods which are smaller than the particle diameter are so arranged so that each comb may be individually moved to the open position and shut again without allowing any of the even sized particles of the bulk material to pass through the other comb while testing the readiness of the comb operating system. Grooves of circular arc cross-section fitting the size of the spheres of a high-temperature reactor are provided in the upstream sides of the wall produced by the interfitting combs to enable close packing of the spheres against the closure wall in an ordered arrangement that allows either comb to be withdrawn and reinserted without breakage of the spherical elements. The grooves are oriented in the length dimension of the comb rods, and one set of comb rods provides the groove bottoms and the adjoining rods of the other set the cooperating groove flanks.