摘要:
Gas-cooled nuclear reactors include circulation systems for cooling gas to remove the heat generated in the reactor core. An improved arrangement includes a plurality of steam generators in a horizontal plane located above the horizontal plane of the reactor core. The cooling gas circulates from the bottom of the reactor core to the top. Improved heat removal is accomplished in this manner as the heated cooling gas enters the steam generators after passage through the reactor core without undergoing further circulation in a horizontal or inverse vertical direction.
摘要:
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. Pourable absorber material provided by means of a reservoir located above the core and introduced into the vertical cavity penetrates the pile of spherical fuel elements in the form of a column, thereby absorbing neutron radiation.
摘要:
A roof reflector comprising at least three individual layers of tapered layer elements combined in the form of vertical columns. Each column rests on a block column of the lateral reflector. Individual elements are secured by wedges and dowels to permit vertical column movements without constraint. The top and bottom layers comprise gas collector spaces communicating with each other by passage openings in the middle layer. In the top and bottom layers are also slot-shaped passage openings leading to an from the collector spaces. Preferably, they are radially offset relative to the passage openings in the middle layer to obtain good gas mixing as it rises through the reflector.Such a roof reflector is useful for avoiding roof reflector element damage if one element is vertically displaced relative to an adjacent element. The roof elements are carefully designed to achieve this end and maintain cover utility.
摘要:
A gas-cooled high temperature reactor having a core filled with spherical fuel elements is provided comprising a graphite side reflector including at least one nose-like projection comprised of a plurality of graphite nose stones stacked one upon the other, said nose stones each including at least one vertically disposed continuous cavity aligned with at least one vertically disposed continuous cavity in adjacent nose stones, said cavity adapted to receive discrete absorber material elements introduced into the reactor core, said nose stones further including at least one vertically aligned continuous gap which extends into said nose stones from a front portion thereof and is aligned with a corresponding continuous gap in adjacent nose stones, communication between said continuous gap and said cavity being prevented, said nose stones also comprising in top and bottom surfaces thereof sealing means which enable adjacent nose stones to be stacked in a manner sufficient to seal said at least one cavity in a gas-tight manner, thus preventing communication between said cavity and said core.
摘要:
In a nuclear reactor installation with a small high temperature reactor (26) all of the components of the primary loop, together with the control and shutdown installations (82, 92, 114, 116; 194, 198, 200) are located inside a steel pressure vessel (16) and may be installed and dismantled from above. This makes an economical subterranean construction possible.
摘要:
A barrier system for a high temperature reactor. The reactor utilizes spherical fuel elements consisting of coated particles of a fissionable material embedded in a graphite matrix, the coating forming a first safety barrier against the release of fissionable material, and the graphite matrix a second such safety barrier. The reactor is surrounded by a prestressed concrete pressure vessel clad on the inside with a metal liner. The metal liner acts as a third safety barrier, while the concrete body of the prestressed concrete pressure vessel forms the fourth, and outermost safety barrier. A plurality of passages are located in the pressure vessel which are closed off by closure means. The closure means provide sealment between the third and fourth barriers in the area of the passages. By utilizing the concrete pressure vessel as a safety barrier in this manner, the need for a separate protective reactor housing is eliminated.
摘要:
A vaulted cover for an opening in a pressure vessel comprising a vaulted center piece and an annular rim surrounding thermal insulation material of a cover flange. The rim is assembled of two coaxially arranged cylindrical sections. Expansion gaps and sealing disks are provided about pipe fittings in said vaulted cover in a manner that permits release of pressure through gaps formed by said sealing disks.
摘要:
Disclosed is a closing arrangement for large passages in a prestressed pressure vessel comprising a cover means for covering the opening of a passage in the prestressed pressure vessel, an annular structural part having an inner boundary surface surrounding the covering means at a distance and defining a space therebetween, a means for securing the annular structural part to the prestressed pressure vessel and a plurality of connecting elements disposed in the space between the annular structural part and the covering means in abutting relationship with the inner boundary surface of the annular structural part and the covering means.
摘要:
A gas cooled nuclear reactor may have a stationary pile of spherical operating elements. The reactor may be controlled and shut down by absorber rods displaceable in channels of the side reflector. The neutron sources required for the safe start-up of such pellet pile reactors, which in the case of higher capacity pile reactors are installed in bores of the side reflector, are arranged in the stationary pile, where they are more effective and do not occupy positions in the side reflector. They may be located in one or more graphite elements having the same diameter as the operating elements. These elements may be introduced and removed into and from the core together with the operating elements and remain stationary in operation.
摘要:
A shutdown system for a high temperature nuclear reactor where absorber material elements in the form of balls pass from an elevated reservoir into a vertical channel formed by aligned vertical cavities in horizontal, nose-shaped projections from the side reflector. The balls are transported back to the reservoir by way of a conveyor device. It must be insured that even in the case of accidents the absorber balls arrive in the cavities and that a rapid return of the absorber balls into the reservoir takes place. For the purpose, the reservoir is provided with an automatically-actuated and controllable device for releasing an opening between the reservoir and the vertical channel feed line. Below the channel is a removal tube terminating in a housing and arranged to form a pile of the absorber balls which seals the removal tube. To return the absorber balls, a metering gas acts on the pile and brings the absorber balls to a carrier gas. The carrier gas returns the absorber balls into the reservoir while the gaseous proporation of the carrier gas flow is returned for the reservoir into the pressure vessel.