Passive ejection of fuel spheres as a high temperature reactor core for the second shutdown system

Abstract

The invention discloses a high-temperature reactor core in which fuel balls are passively discharged as a second shutdown system. The core includes several fuel balls and conduits; the several fuel balls are arranged in the core active area, and the core active area The interior is also filled with molten salt coolant; one axial end of the conduit communicates with the active area of ​​the core, and the other axial end communicates with the outside. The invention provides an advanced high-temperature reactor core that uses the principle of thermal expansion and contraction of molten salt to discharge fuel balls as the second shutdown system. Under accident conditions, the temperature of the molten salt rises and the volume expands, causing core pressure Elevate, passively open the one-way pressure reducing valve, discharge the core coolant and fuel balls, reduce the fuel loading of the core, reduce the reactivity of the core, maintain long-term shutdown, and ensure the safety of the core.

Description

technical field [0001] The invention relates to the technical field of nuclear reactors, in particular to a high-temperature reactor core in which fuel balls are passively discharged as a second shutdown system. Background technique [0002] Reactor-related safety regulations require that the shutdown means must consist of two different systems. The second shutdown system is a defense-in-depth means to prevent failure of the reactor protection system shutdown. At least one of the two systems is capable of independently performing the function of rapidly bringing the reactor into subcriticality with sufficient depth from operating conditions and accident conditions under a single failure condition. Even in the case of maximum backup reactivity of the core, at least one of the two systems can independently make the reactor enter the subcritical state from normal operating conditions, and maintain the subcritical state with sufficient depth and high reliability to maintain saf...

AI Technical Summary

Problems solved by technology

At present, in order to meet the requirements of relevant safety regulations, the second shutdown system of the pebble bed advanced high temperature reactor also uses control rod control, which must occupy some control rod positions in the reflective layer, which makes the control rods available for the first shutdown system The reduction in the number of roots, that is, the reduction in the total value, seriously affects the design of the power and life of the pebble bed advanced high temperature reactor, which in turn limits the economics of the pebble bed advanced high temperature reactor

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