Optimum design method for reactor core fusion collector

Abstract

The invention discloses an optimum design method for a reactor core fusion collector. Modeling is conducted on a simplified reactor core fusion collector, and according to the symmetrical border, modeling is conducted on part of trays; a fusant is simplified to a cylindrical shape, the initial condition is set as complete fusion of a box of fuel elements, and the fused fuel elements fall from a big grid plate to a top cover of the reactor core fusion collector and the trays; a three-dimensional DEM method is adopted for calculation, at least ten sample points are uniformly taken from the calculated result in the radial direction, and non-dimensional unevenness sigma is defined to quantize the influences of different structures and sizes of reactor core fusion collectors on the distributionof the forming thickness of a debris bed. Through simplified modeling, the required time of DEM modeling calculation is greatly reduced, the calculation accuracy is ensured, the determination difficulty of calculation parameters is reduced, and definition unevenness provides basis for the design optimization of reactor core fusion collectors.

Description

technical field [0001] The invention belongs to the technical field of nuclear reactor safety facility design, and in particular relates to an optimal design method of a reactor core melting collector. Background technique [0002] The core disintegration accident is a kind of beyond design basis accident in the sodium-cooled fast reactor. After the core melts and disintegrates, the bottom of the main vessel of the sodium-cooled fast reactor is directly below it. A core melt collector to ensure the integrity of the main vessel after a core disintegration accident. [0003] At present, the main structure of the core melting collector in a sodium-cooled fast reactor includes a tray, a channel, a channel roof and a support frame. The tray is fixed on the supporting frame, and there are fixed channels with an indefinite number on the tray. The central channel is located on the central axis of the tray and the supporting frame, and passes through the tray. There is a channel to...

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Problems solved by technology

[0004] However, there are difficulties in the design process of the structure and size of the core melting collector

In terms of structure, parameters such as the number and position of the surrounding channels above the pallet are difficult to determine

In terms of size, such as the diameter and height of the central channel and surrounding channels; the height and inclination angle of the top cover of each channel; the diameter of the tray bottom plate, and the determination of the height of the cylinder has no evaluation basis, and it is difficult to obtain the optimal reactor for the reactor. Core Melt Collector Design

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