An embedded dual-flow supercritical water reactor fuel assembly

Abstract

The invention discloses an embedded double-flow supercritical water reactor fuel assembly, which includes a fuel rod and a guide pipe, and also includes a component box, a water rod box, and a heat insulation box. The component box and the heat insulation box are both tubular structures, and the assembly The box, the heat insulation box, the guide pipe, and the fuel rods are in a parallel relationship with each other; the component box is sleeved on the outside of the heat insulation box, and the two ends of the component box are located between the two ends of the heat insulation box; inside the heat insulation box, Fuel rods are arranged in the space between the outer wall of the heat insulation box and the inner wall of the component box, and the guide pipe is arranged in the heat insulation box; the second process coolant outlet and the second process coolant outlet are also set on the component box. The inlet, the coolant outlet of the second process and the coolant inlet of the second process are all located on the side wall of the component box; the water bar box is a tubular structure arranged in the heat insulation box, and the length direction of the water bar box is in line with the insulation box. The length direction of the heat box is in the same direction. The fuel assembly has a simple structure and can effectively improve the economy and safety of the fuel assembly during manufacture and use.

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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