Embedded type double-process supercritical water reactor fuel assembly

Abstract

The invention discloses an embedded type double-process supercritical water reactor fuel assembly, comprising fuel rods, a guide tube, an assembly box, a water rod box and a heat insulation box, wherein the assembly box and the heat insulation box respectively have a tubular structure, and the assembly box, the heat insulation box, the guide tube and the fuel rods are parallel to each other; the assembly box sleeves the outer side of the heat insulation box, and two ends of the assembly box are positioned between two ends of the heat insulation box; the fuel rods are arranged in the heat insulation box and a space between the outer wall of the heat insulation box and the inner wall of the assembly box, and the guide tube is arranged in the heat insulation box; the assembly box is also provided with a second process coolant outlet and a second process coolant inlet, and the second process coolant outlet and the second process coolant inlet are formed in the side wall of the assembly box; the water rod box is in the tubular structure arranged in the heat insulation box; the length direction of the water rod box is the same as that of the heat insulation box. The fuel assembly is simple in structure and can effectively improve the economy and safety during manufacture and use of the fuel assembly.

Description

technical field [0001] The invention relates to the technical field of nuclear reactor structures, in particular to an embedded double-flow supercritical water reactor fuel assembly. Background technique [0002] Supercritical water-cooled reactor (SCWR) is one of the six most promising nuclear energy systems screened out by the Generation IV Nuclear Energy International Forum. SCWR nuclear power unit has outstanding advantages such as high thermal efficiency and simplified system. In order to solve the problems of insufficient neutron moderation in SCWR, large temperature difference between the core inlet and outlet, and flow instability, the "water rod" design was introduced in the design of the thermal neutron spectrum component, and the coolant used in the core design uses multi-flow flow The design of components and core structure is extremely complex and difficult to manufacture. In addition, a fast neutron spectrum supercritical water reactor fuel assembly without "...

AI Technical Summary

Problems solved by technology

However, the average density of supercritical water reactor coolant is low, which will lead to negative water density reactivity coefficients for designs without "water rod" fuel assemblies, which seriously affects the inherent safety of the core.

For this reason, it is necessary to introduce solid moderator materials into the components, such as ZrH, graphite, etc., which brings great difficulties to the design of the core batch refueling scheme

In addition, the coolant flow scheme adopts a dual-flow design, and the upper part of the reactor core needs to be equipped with a special low-temperature coolant and high-temperature coolant diversion structure, which also makes the structural design of the upper part of the core very complicated, which brings great difficulties to the installation of reactor internals and related equipment. more difficult

Under ideal conditions, the safety design requirements are basically met. If manufacturing deviations and actual operation are considered, the feasibility of thermal spectrum / fast spectrum fuel assembly and core design will face great challenges

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