Grid type control drum device of small fast neutron reactor

Abstract

The invention relates to a grid type control drum device of a small fast neutron reactor. The grid type control drum device comprises an inner reflecting layer, a grid type control drum and an outer reflecting layer which sequentially sleeve the periphery of a reactor core from inside to outside, and a driving motor for driving the grid type control drum; the inner reflecting layer is in a cylindrical grid shape and is fixed in position; the outer reflecting layer is in a complete cylinder shape and is fixed in position; and the grid type control drum is in a cylindrical grid shape and can bedriven by the driving motor to rotate by a certain angle so as to adjust the overlapping area between the absorption grids and the reflection grid of the inner reflecting layer and change the number of leaked neutrons reflected back to the reactor core, so reactivity control is achieved. The device disclosed by the invention is small in occupied axial space, and meets the miniaturization design requirement; the absorption grids have no axial displacement, so that uneven axial power distribution of the reactor core cannot be caused; and the absorption grids are in central symmetry about the central axis of the reactor core, have good adaptability to material expansion caused by radial temperature gradient, and are not easy to block due to deformation.

Description

technical field [0001] The invention relates to the technical field of nuclear reactor reactivity control, in particular to a grid control drum device suitable for the reactivity control of small fast neutron reactors. Background technique [0002] Miniaturization and modularization are a new trend in the development of current reactor technology. Small fast neutron reactors have many advantages such as high power density, high thermal efficiency, multiplication ability, transmutation, and flexible application scenarios, and have broad development prospects. [0003] The main task of the reactivity control design is to adopt various practical and effective control methods to control the residual reactivity of the reactor under the premise of ensuring safety, so that the power distribution of the core is flat, which can cope with the changes caused by the external load changes, and in the In the event of an accident, the reactor can be shut down quickly and safely. Starting...

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Problems solved by technology

The disadvantages of this patent are: 1) Due to the high temperature of the metal stack, there is a large temperature gradient in the reflective layer along the radial direction, so the degree of thermal expansion at different positions of the columnar control drum is different. Rotation, it is likely to be stuck due to deformation, resulting in device failure, and the consequences are very serious; 2) In order to increase the reactivity share that can be introduced, the columnar control drum often needs to increase the diameter of the control drum, resulting in the overall required radial diameter of the reactivity control device. The space is too large, which is not conducive to the miniaturization of the device; 3) Each columnar control drum needs to be equipped with a motor, which is not conducive to the miniaturization of the device

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