Non-uniform tubular MA transmutation rod with reactor core axial power flattening function

Abstract

The invention discloses a non-uniform tubular MA transmutation rod with a reactor core axial power flattening function. The rod comprises a central layer which is located at the center of the non-uniform tubular MA transmutation rod, a 6LID / MA / UO2 mixed fuel layer is arranged outside the central layer, an air gap layer is arranged outside the 6LID / MA / UO2 mixed fuel layer, and a zirconium alloy cladding is arranged outside the air gap layer. An odd number of sections of 6LID / MA / UO2 mixed fuel layers are arranged in the axial direction of the non-uniform tubular MA transmutation rod. From the upper end to the middle position of the non-uniform tubular MA transmutation rod, the proportions of MA nuclide in the sections of the 6LID / MA / UO2 mixed fuel layers are gradually increased section by section . From the middle position to the lower end of the non-uniform tubular MA transmutation rod, the proportions of MA nuclide in the sections of 6LID / MA / UO2 mixed fuel layers are gradually reduced section by section. The non-uniform tubular MA transmutation rod provided by the invention improves the transmutation rate of MA nuclide, has a flattening effect on the radial and axial power of a reactor core, can improve the conditions that the neutron flux in the reactor core is too high and the external flux is very low, and reduces the power peak factor of each component in the reactor core.

Description

technical field [0001] The invention belongs to the technical field of pressurized water reactor nuclear fuel transmutation components, more specifically, the invention relates to a non-uniform tubular MA transmutation rod with the function of flattening the axial power of the core. Background technique [0002] There are many sources of nuclear waste, and spent fuel from reactor operations accounts for the vast majority. It contains a large amount of radioactive waste, and radioactive waste can be divided into low, medium and high radioactive waste according to the radioactive level, and divided into short, medium and long according to the length of the half-life. Among them, the most urgent and public concern is how to dispose of the large amount of high-level radioactive waste generated by nuclear power plants, especially how to dispose of long-lived high-level radioactive waste (Long-lived High Level Wastes, LHLW for short). [0003] Long-lived high-level radioactive wa...

AI Technical Summary

Problems solved by technology

[0008] 237 Np, 241 Am, 243 Am, 244 The fission cross sections of the four MA nuclides, Cm nuclides, are higher in the high-energy region (E>1MeV), and are comparable to 235 The fission cross section of U in this energy region is equivalent, but it is very small in the low energy region, and 235 The fission cross section of U in the low-energy region is more than two orders of magnitude lower than that, so directly loading MA nuclide into the PWR has a lower direct fission rate

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