First criticality method for anti-neutron trap research reactor

Abstract

The invention provides a first criticality method for an anti-neutron trap research reactor. The first criticality method comprises the following steps: performing the subcritical extrapolation by adopting an element method; when the difference between an extrapolated result and an actual fuel assembly loading number of a core is less than 1, switching the element method critical extrapolation torod position method critical extrapolation, under the current core loading, inserting all control rods into the core, then loading a fuel assembly into the core, gradually lifting the control rods step by step, and carrying out the subcritical extrapolation by adopting the rod position of the control rods, gradually transiting the reactor to the critical state step by step, thereby realizing the first criticality. By combining the element method and the rod position method, the problem that a single criticality experiment method does not meet the requirements of the first criticality experiment of the anti-neutron trap research reactor can be solved.

Description

technical field [0001] The invention relates to the field of atomic energy, and further relates to a method for the first criticality of an antineutron trap type research reactor. Background technique [0002] The first criticality is a key link in the construction process of a research reactor and the only way to pass, marking that the reactor has the conditions to increase its power and gradually transfer to operational applications. The critical methods commonly used in reactors include water level method, component method and control rod rod level method, which method depends on the actual situation of the reactor and its own characteristics. The water level method refers to gradually adding heavy water or light water to the core to reduce the leakage of neutrons under a certain fuel load, so that the reactor is gradually approaching the critical state. The element method makes the reactor gradually approach and finally reach the critical state by adding fuel elements t...

AI Technical Summary

Problems solved by technology

The antineutron trap type research reactor has a compact core structure and many external channels, and most of them adopt the design of separating the core coolant circuit from the external moderator circuit, which makes it difficult to implement the traditional water level method and cannot meet the requirements of this type of reactor. first critical requirement

In addition, due to the small loading of fuel assemblies in the core, in order to ensure that the reactor has sufficient backup reactivity, the reactivity value of a single fuel assembly is often larger, usually exceeding 1% Δk / k, which makes the traditional element method unable to meet Requirements for the first critical experiment

Therefore, although the antineutron well research reactor has the advantage of high performance, its construction, especially the first criticality, is facing huge difficulties and challenges. A reliable experimental method must be established to ensure its safe and smooth first criticality

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