Thermally insulating closure system for pressure relief apertures in separating walls, particularly in nuclear reactor buildings.

The invention relates to a heat insulating closure system for pressure relief openings of partitions, in particular those of nuclear reactor buildings, according to the preamble of claim 1.

DE-AS 21 60 991 a closure system for pressure relief openings in the biological shield of a nuclear reactor pressure vessel is known in which the circumference of the reactor pressure vessel around distributed in biological shield more filled with shielding shielding chambers are provided, the gas-tight to the outside through glass panes with a burst pressure have been completed.

A similar closure system is disclosed in DE-AS 27 19 923 wherein the discharge orifices closing screening of a grid structure consist whose meshes are filled with granular shielding material. The grid-shaped construction is anchored with the aid of a frame in the opening of a partition wall, and the lattice meshes are closed by sheet metal discs, which are ejected at a certain overpressure occurrence together with the granulate.

The present invention is also made of by a reactor side overpressure outward pressable from its anchorage fastener elements in lightweight construction. However, the closure elements should be particularly thermal insulation. They are arranged in particular in the area of ​​penetration of the main coolant nozzle of the reactor pressure vessel through the biological shield. In the event of a postulated break (unlikely in itself) a main coolant pipeline would flow coolant through an in size to a specific cross-section, for example, 200 sq cm, fixed leakage between a double pipe and the main coolant nozzle in an annular space formed by the reactor pressure vessel and the biological inner shield , The overpressure thus built must be dismantled intrinsically safe. The biological inner shield together with the outer support plate, on which the supporting structure of the reactor pressure vessel is mounted and anchored, the entire biological shield. But it is not just about the loss any excess pressure; the Stutz space must also be insulated to prevent heat dissipation to the outside. The Stutz room insulation so is the separation of the pressure-loaded area to the annular gap, which gets its geometry from the support plate and inner plate.

The invention has for its object to provide a heat insulating closure system for pressure relief openings of partitions of the type mentioned by which a konvektionsdichter completion of the pressure relief openings is provided and which has the same efficiency as regards its insulation as the subsequent thermal insulation system. Additional requirements to be met by the invention are the following: Mathematically and experimentally exactly detectable burst pressures for the closure system; Design of the fastener elements and of the closure system in such a way that jamming or skewing is impossible within the pressure relief opening during the Ausschiebevorgangs, and finally a lightest possible design of the fastener elements, which are pushed out in response case from the pressure relief opening to damage of components of the environment avoid.

According to the invention the object is achieved by the features specified in the characterizing portion of claim 1. Further developments of the subject invention are described in the dependent claims.

The advantages attainable with the invention advantages are mainly to be seen in that the cassette inserts are lightweight components with high thermal insulation properties, through which pressure relief openings are now also allows the neck region of space, particularly in pressurized water reactor plants.

In the following the invention will be with reference to several embodiments which are shown in the drawing, explained in more detail. It shows:<ul><li>FIG. 1 is simplified as a cut-neck region of space in a pressurized water reactor with heat-insulating partition wall and a closure member;</li><li>Figure 2 shows the section AA of Figure 1, ie the closure member with its seat in partial section..;</li><li>Figure 3 shows a second embodiment in a representation corresponding to Figure 2 with a glass pane as Bersthaut..;</li><li>. Fig. 4 is a 3 slightly modified in comparison to FIG clamping of the glass pane (third embodiment);</li><li>Figure 5 shows a fourth embodiment which is similar to that of Figure 3, but are used instead of mineral fibers as insulation material spaced apart metal foils..;</li><li>Figure 6 shows a fifth embodiment with a bursting film instead of a glass pane as Bersthaut.</li><li>. Fig. 7 shows detail A of Figure 3, 4 and 6 enlarged;</li><li>Fig. 8 with its biological shield in the neck to show a nuclear reactor pressure vessel, the position of the insulating closure system; and</li><li>FIG. 9 is a developed view of one half of the insulating closure system for the neck region of space a pressurized water reactor.</li></ul>

The thermal insulation shutter system is arranged according to FIG. 1 in the neck region of space of a pressurized water nuclear reactor, indicated its neck contour at 1 and the heat-insulating partition having 2 pressure relief openings 3, which are closed with closure elements 4 in the form of thermal insulation cassette inserts. Fig. 1 shows only such a cassette insert 4; Fig. 9, however, shows a larger section with several cassettes inserts, whereupon yet been received.

Fig. 2 shows that the thermal barrier formed as a cassette insert closure member 4 abuts with a peripheral shear edge 4a at its front side to an outer sealing Bersthaut fifth The latter is welded gas-tight at the periphery of the limited from the inside IS to the outside AS by conical or truncated pyramid extending walls 6 pressure relief port 3, for which the bursting film 5 is provided with a beaded edge 5a, which at the angled edge 2a1 of the outer end wall 2a of the partition 2 abuts the inner end wall is indicated with 2b. The partition 2 is performed in all-metal insulation at 2.1 indicated, approximately plane parallel beabstandetenDämmfolien which 2a, the air-filled Dämmzellen 2.2 bil to between itself and the inner and outer end wall 2b. The boundary wall 6 of the pressure relief opening 3 is also formed by a metal film which is gas-tightly welded to angled edge portions 6a at the outer side AS and 6b on the inside IS against the outer end wall 2a and the inner end wall abuts 2b and with these walls.

Trained as a metal foil Bersthaut 5 is dimensioned in its thickness (in pressure difference direction) so that the cassette insert 4, the Bersthaut with the circumferential shear edge shears off upon reaching or exceeding the allowable pressure difference between the inside and the outside IS, AS 4 and even from his seat is pressed. It then falls to the outside, but, since it is a lightweight construction, adjacent walls or components do not damage.

Thus, in the illustrated embodiment, the Bersthaut a thickness of 0.4 mm; behind it is the shearing edge 4a having print film 4.1. Behind turn are a number of insulating foils 4.2 spaced apart to form Dämmzellen 4.3 stacked, the number of which depends on the thickness of the Dämmpaketes or the partition wall thickness. The conical enclosure 6 is made of about 1 mm thick Austenitblech. In the construction shown in Fig. 2 when the aforementioned differential pressure occurrence are the films 4.2, beginning on the pressure side (IS = inner side) of the system together. The smallest area of ​​film 4:20 is on the pressure side. Thus, a jamming or tilting of the slides 4.2 is avoided. After dipping the films together the load on the 1 mm thick print or intermediate film acts 4.1. This rigid insert is now bringing the pressure load as a thrust force on the densely verschweiße to the frame of the surrounding insulation system 0.4 mm thick bursting film 5 and shears from these. It follows the expulsion des'kompletten insert; the overflow cross stands for the medium to flow out openly.

In the embodiment of FIG. 2 so the cassettes insert is 4 in all-metal, the insulating foils are 4.20 4.2 and 4.1 respectively doubly bent V-shaped at its outer edge and abutting the outer leg of their folds each konvektionshemmend on the bottom surface of the adjacent insulating foil.

In the second embodiment of FIG. 3 the cassette insert 4 contains as an insulating material of mineral fibers 8, and also the partition 2 contains instead of insulating foils mineral fibers 7. The Bersthaut 5 here is a glass bursting disc which is sealingly clamped on the dividing wall region surrounding the cassette insert 4. The seat of the bursting insert 4 is again formed by the conically tapering from the interior IS to the exterior AS boundary wall 6, and on the inner circumference of the boundary wall 6, a further corresponding tapered insert 9 is inserted, which on its outer side with a shoulder 9a of the seat for the glass pane 5 'forms. The insert 9 is in its outer edge region with the boundary wall 6 welded gas-tight at the 10th At paragraph 9a a clamping screw 11 is anchored and gas-tight welded, their previous outward end 11, a holding plate 12 is pushed with corresponding through holes. Around the outer edge 13 of the glass pane 5 '14 is laid around a U-shape a sealing strip; it consists of a heat-insulating seal material using asbestos. The holding plate 12 is pressed from the nut 11b with washer 11c against the sealing strip 14 and the edge 13 and presses these parts sealing against the shoulder 9a. OWNER Liche bursting 4 has an outer Metal foil with the end plates 15a, 15b and the casing plate 16th The casing plate has on the outside and inside of AS, IS respectively a peripheral projecting edge 16a, 16b with the end plates 15a, 15b respectively welded gas-tight. For this purpose, the end plates 15a, 15b are folded over at its outer edge. The peripheral projecting edge 16b is provided in this embodiment with an acute-angled tapered Berstkante 16b1 as the detail A of FIG. 7 shows in more detail. Thus, a fraction determination edge is formed on the glass plate 5 presses upon actuation 'and this brings to burst due to the shear stress, after which the cartridge insert is 4 again ejected.

Fig. 4 shows a third embodiment, a variant in comparison to Fig. 3 in that the sealing strip 14 the edge 13 of the glass disc 5 'does not include U-shaped, but merely abuts on one side. Incidentally, the embodiment is as in FIG. 3.

The fourth embodiment of Fig. 5 agrees again with that of FIG. 3 except for the fact agree that both the partition 2 and the closure member 4 having a metal foil insulation and the shear edge of the print sheet 4.1 is formed as the shearing edge 4a of Fig._' . 2

In the fifth embodiment of FIG. 6 is also for the partition 2 and the closure member 4, a metal foil insulation provided in accordance with FIG. 2, however, is different from the embodiment of FIG. 5 no glass bursting disc but a metallic bursting film 5 to complete the printing t Relief Port 3, the is formed in this case by the conical seat plate 9 is provided. The formation of the shearing edge 16b1 (see. Fig. 7) is such as that shown in FIGS. 3 and 4. It is again formed by a projecting edge of the casing plate 16.

The cut-out of FIG. 8 leaves the outer supporting plate 17 and the inner plate 18 of a biological shield for a nuclear reactor pressure vessel 19 with support 1 recognize. Intermediate support plate 17 and inner plate 18, an annular gap 20 is arranged, which serves inter alia to shield cooling, and further deplete any overpressure which may degrade arranged by the supporting plate 17 at its uriteren (not shown) end overflow with overcurrent flap. As enshrined in the supporting plate 17 ring box girder 21 forms each with over the circumference of the pressure vessel brackets 19 distributed 22 supports for the support lugs 23 of the pressure vessel 19. The Wiederholungsprüftür 24, which allows access to the annular gap 25 between pressure vessel 19 and inner shield 18 forms a part the partition 2 in the neck region of space.

FIG. 9 is a cut-processing the partition in said Stutz area with the neck-through openings 26, the Wiederholungsprüftüren 24 and indicated as such by diagonal lines, designed as a bursting elements fastener elements 4. Of the eight nozzle penetrations 26 are shown only two, the settlement therefore sweeps over a little more than 45 °. About the Wiederholungsprüftüren 24 to partition recesses are 27 where the support brackets 22 (see. FIG. 8) project into the dividing wall region.

The particular advantage of the closure system is that the partition 2 trial can be mounted outside the reactor building completely modular system (see the joints 28 between the individual partition blocks) produced and. If all the measurements are correct, the installation in the area of the inner shield can (Fig . 8) carried out successively.