LU80638A1 - COLLECTION DEVICE - Google Patents

Description

y EUROPEAN ATOMIC SOCIETY (EURATOM)

Patent application

Fall arrester

State of the art

Collecting devices for the core of liquid-cooled nuclear fission reactors are known, in particular for the cores of so-called rapid-breeding reactors cooled with sodium. In the event of a malfunction, these fall arresters collect the debris from the destroyed real core. The debris made of nuclear fuel and structural parts of the reactor core hit the collecting device very hot and even in a molten state. The temperature increase to be expected on the surface of the collecting device in the event of a fault is a maximum of 1000 ° C.

XIIl / 1920 - 2 - 1, ..- 2-- »'i Ί,; ,] i task

The invention specified in claim 1 is based on the object of the maximum temperature that previously occurred in the collecting device.

To lower the increase. It is thereby achieved that the structural material of the collecting device retains a mechanical skill which is necessary for the load-bearing capacity of the collecting device.

Advantages "

The advantage of the invention lies in the fact that through the layer of porous material, which has an open porosity of approx. 60-80%, there is a convection current against gravity; setting of the coolant for the accident in which the upper; surface of the porous layer is heated by hot debris of the reactor core j. As a result, the heat contained in the hot debris is released to the coolant. Apart from a slight increase in temperature due to thermal conduction over the porous layer, the surface of the collecting device remains essentially on I ’·! the temperature of the coolant.

Presentation of the invention An embodiment of the invention is described below with reference to two schematic drawings.

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Figures 1 and 2 show embodiments of the porous layers in the form of wire mesh. Figure 3 shows schematically in a sectional drawing through the reactor vessel the position of the collecting device, the porous layer and the coolant chamber.

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FIGS. 1 and 2 show two different types of stacking of wire runs, with which an exemplary embodiment is used to produce a porous layer.

Figure 1 shows a stack without engagement of two wire rifles, from the wires 1 of the one fabric and 2 of a second fabric.

The two mats have a maximum distance in FIG. 1, so that the channels of the open porosity also have a maximum volume.

The convection flow of the coolant 3 takes place in the arrow direction 4 away from the surface of the catching device 5.

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FIG. 2 shows a stack with the engagement of two wire meshes from the wires 1 of one mesh and the wires 2 of the second mesh. Eggs, the stack height is not maximum, so that the volume of the open porosity is smaller than in the embodiment according to FIG. 1,

The convection flow of the coolant 3 takes place in the direction of the arrow 4 away from the surface of the catching device 5. The wire mesh, which usually consists of stainless steel like the collecting device 5, is stacked into a porous layer and sintered or welded together.

It can be seen from FIG. 3 that the collecting device 5 is arranged in the lower part of the reactor vessel 6 below the reactor core 4. The reactor vessel is filled with the coolant 3. The layer of porous material 7 is arranged on the plate 8 of the safety device 5.

λ * XIIl / 1920 - 4 -

Claims (1)

\ ’V i m Claim claim device for the core of a liquid-cooled nuclear fission: reactor, in particular a sodium-cooled fast breeding reactor, characterized in that the side of the collecting tube facing the core! direction with at least one layer of a material with open porosity. * * * λ - *% \\ «la Coi3f: rssi <· a o j J · laisjoy ß n XIIl / 1920 # //