Shielding assembly structure with high-efficiency shielding properties

Abstract

The invention belongs to the technical field of shielding of fast-neutron reactors, and particularly relates to design of a shielding assembly structure with high-efficiency shielding properties. On the basis of maintaining the hexagonal outer sleeve, the inside of the shielding assembly is filled with shielding element balls from bottom to top, thereby simplifying the original design of the end plugs, cavity, holddown spring and wrapping wire of the shielding element bar, and enhancing the neutron and gamma-ray radiation shielding properties of the shielding assembly. The two-layer ceramic material design of the shielding element balls ensures the completeness and reliability of the shadowing assembly in the operation period; the loose pyrolytic carbon ceramic material of the inner layer provides storage space for the radiation activation product, absorbs the radiation-induced swelling of the boron carbide shielding material, and buffers the stress caused by the temperature and radiation; and the compact and isotropic pyrolytic carbon ceramic material of the outer layer provides a second protection layer, thereby preventing the loose pyrolytic carbon ceramic material layer of the inner layer from mechanical damage, and further enhancing the safety of the shielding element balls.

Description

technical field [0001] The technical field of reactor fast neutron shielding, in particular to a structural design of shielding components with high-efficiency shielding performance. Background technique [0002] There are many kinds of radiation in the nuclear reactor, and most of the radiation is harmful to the materials of the equipment. The radiation damage will change the performance of the equipment materials and affect the normal operation of the reactor. Among them, neutron and gamma-ray irradiation are the main causes of radiation damage to reactor materials. In order to prevent excessive radiation damage to structural materials in the reactor and protect the reactor vessel itself, fast neutron reactors need to arrange shielding components around the core. Perform axial shielding. [0003] In the prior art, the fast reactor shielding assembly mainly adopts the design of shielding element rods. The shielding element rods are arranged in an equilateral triangle. A s...

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Problems solved by technology

[0004] (1) Since the end plug, air cavity, and compression spring in the shielding rod of the shielding assembly occupy a certain volume, the shielding effect of the shielding assembly on fast neutrons and gamma rays at the height where the end plug, air cavity, and compression spring are located Weakening, so that the radiation received by the reactor vessel at the same height increases, which is not conducive to the long-life use of the reactor vessel;

[0005] (2) The shielding component is in the harsh environment of high radiation, high temperature and high pressure for a long time, the boron carbide core block in the shielding element rod is easy to contact with the cladding, causing radial deformation and swelling of the cladding;

[0006] (3) The structure of the shielding element rod makes industrial processing more difficult

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