Abstract
A device for confining nuclear reactor core melt comprising a melt trap and provided with a multilayer vessel containment, a filler, an upper support, and a bottom support comprising a horizontal embedded plate mounted in the concrete of a reactor pit. The plate comprises radial supports, the melt trap comprising radial supports, based on the radial support of the plate. The plate radial supports and the melt trap radial supports are connected with fasteners having holes in the form of hyperbolic surfaces. The radial supports and the clamps have oval holes. The upper support comprises turnbuckles, mounted in pairs on the upper part of the melt trap body so that the longitudinal axis of each radial support of the melt trap bottom support passes in projection at an equispaced distance from the fitting location of the paired turnbuckles and connecting the melt trap body with the reactor pit vertical wall.
Claims
1. A device for confining the melt of a nuclear reactor core, comprising: a melt trap body configured to be mounted below a bottom of a reactor vessel, the melt trap comprising a cooled multilayered housing; a filler for diluting melt, the filler being arranged in the multilayered housing; an upper melt trap support; and a lower melt trap support comprising a horizontal embedded plate mounted under the multilayered housing and configured to be mounted in concrete of a reactor shaft; wherein the embedded plate comprises lower radial supports and the multilayered housing comprises upper radial supports resting on the lower radial supports of the embedded plate; wherein the lower radial supports and the upper radial supports are connected by means of fasteners and comprise oval holes, and the fasteners have openings in the form of hyperbolic surfaces; and wherein the upper melt trap support comprises a plurality of turnbuckles mounted in pairs on an upper part of the multilayered housing such that, from a top view of the melt trap body, each lower radial support extends in projection equidistantly from file attachment points of corresponding paired turnbuckles of the plurality of turnbuckles, the corresponding paired turnbuckles mounted tangentially to the melt trap body and configured to connect the melt trap body to a vertical wall of the reactor shaft.
2. The device of claim 1, the embedded plate being a sectional embedded plate.
3. The device of claim 1, the embedded plate being a solid embedded plate.
4. The device of claim 1, the embedded plate being an embedded plate made of separate pieces.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1 shows a device for confining nuclear reactor core melt executed in accordance with the claimed invention;
(2) FIG. 1a shows an enlarged view of the upper support;
(3) FIG. 1b depicts a schematic illustrative example of a top view of portions of the upper support and the bottom support and illustrates how the installation sites of paired turnbuckles can be equidistant from the longitudinal axis of a lower radial support of the bottom support
(4) FIG. 1c depicts a schematic illustrative example of a solid embedded plate of the bottom support that is made of a single piece;
(5) FIG. 1d depicts a schematic illustrative example of a split embedded plate of the bottom support that is divided, for example, into two concentric parts;
(6) FIG. 1e depicts a schematic illustrative example of a sectional embedded plate of the bottom support, which can be, for example, in the form of 4 sections;
(7) FIG. 2 depicts a schematic illustrative example of a pair of turnbuckles mounted on a flange at the upper part of the melt trap body.
(8) FIGS. 3, 4a and 4b depicts a schematic illustrative example of pull rods of the turnbuckles having holes made in the form of hyperbolic surfaces, in which fasteners of the upper support are installed.
DETAILED DESCRIPTION
(9) The claimed invention is functioning as follows.
(10) FIG. 1 shows the device (1) for confining nuclear reactor core melt containing melt (3) trap (2), which is installed in the reactor vessel bottom (18) and provided with a cooled containment as the multilayer vessel, a filler (4) for the melt (3) dilution, placed in the specified multi-layered vessel, the bottom support (5) consisting of the radial supports (6) positioned on the external side of the melt (3) trap (2) bottom part body (7) and based on the radial supports (8) of the horizontal embedded plate (9) which are connected with fasteners (10), the upper support (11), that comprises turnbuckles (12), mounted in pairs on the upper part of the melt (3) trap (2) body (7) so that the longitudinal axis (B) of each radial support (6) of the melt (3) trap (2) bottom support (5) passes in projection at an equispaced distance from the fitting location of the paired turnbuckles installed (13) tangentially to the melt (3) trap (2) body (7) and connecting the melt (3) trap (2) body (7) with the reactor pit vertical wall (14); the cross section (C) of the turnbuckle attachment to the trap body, which is also illustrated in FIG. 4.
(11) FIG. 1a shows an enlarged view of the upper support (11) with turnbuckles (12), and the fitting location of the paired turnbuckles (13), with additional details being illustrated in FIG. 2.
(12) FIG. 1b shows a top view of a portion of the upper support and bottom support and illustrates how the installation sites of paired turnbuckles can be equidistant (e.g., a distance (A)) from the longitudinal axis (B) of a lower radial support of the bottom support. As illustrated, the longitudinal axis (B) of the lower radial support is perpendicular to the sheet and directed upwards as also illustrated in FIG. 1.
(13) FIG. 1c shows an example of a solid embedded plate of the bottom support.
(14) FIG. 1d shows an example of a split embedded plate of the bottom support that is divided, for example, into two concentric parts.
(15) FIG. 1e shows an example of a sectional embedded plate of the bottom support, which can be, for example, in the form of 4 sections.
(16) FIG. 2 shows an example of a pair of turnbuckles (12) mounted on a flange (17) at the upper part of the melt trap (2) body.
(17) As shown on FIG. 3, FIG. 4a, and FIG. 4b the pull rods (15) of the turnbuckles (12) have holes (16) made in the form of hyperbolic surfaces, in which the axes (19) of the fasteners (20) of the upper support (11) are installed. When changing the position of the pull rods (15) of the turnbuckles (12) connecting the body (7) to the fitting locations (13) of the paired turnbuckles (12), the pull rods (15) rotate in the axial plane passing through the axis of each turnbuckles (12).
(18) At the moment of the reactor vessel destruction, the core melt (2) under the action of hydrostatic and overpressure begins to flow into the double body (7) of the melt trap and comes into contact with the filler (4).
(19) In the case of a non-axisymmetric peak of the melt (2) discharge, for example, 60 tons of superheated steel for 30 seconds, the main shock load falls on the side inner wall of the body (7) of the melt (3) trap (2).
(20) As shown on FIG. 2, in this case, those turnbuckles (12a), in the area of which the effect of a non-axisymmetric axial shock load has appeared, do not have mechanical resistance to the shape of the flange (17) of the body (7). Thus, the body flange (17), in the area of which the axial impact has appeared, redistributes the shock load along its perimeter, redistributing the axial impact into two additional components with the formation of both azimuth (along the perimeter of the body (7)) and radial (planar) vibrations. A part of the impact in the form of axial elastic vibrations of the body (7) does not affect the turnbuckles (12a), azimuth vibrations are damped by elastic deformations of the turnbuckles (12b), and radial vibrations propagating in the plane of the turnbuckles (12a) are alternately damped by them, as when a radial shock load is damped.
(21) The radial shock load is damped as follows. A part of the turnbuckles (12a) will work for compression, part—for stretching in the turnbuckles (12) plane. In this case, the horizontal shock load leads to planar vibrations of the body (7) flange (17), in which all turnbuckles (12) work alternately for tension and compression in the area of elastic deformations of the turnbuckles (12), up to the attenuation of the planar vibrations.
(22) The use of the upper support together with the bottom support in the device for confining nuclear reactor core melt made it possible to completely eliminate the probability of the melt release outside the melt trap body by excluding its overturning, even when exposed to a non-axisymmetric shock load.
INFORMATION SOURCE
(23) 1. Russian Patent No. 2398294, IPC G21C 9/00, priority dated Apr. 15, 2009. 2. Japanese Patent JP2010271261, IPCG21C9/00, priority dated May 25, 2009.
