A system and method for measuring the subcriticality of a neutron tube reactor

Abstract

Belonging to the technical field of reactor subcriticality measurement, the invention in particular relates to a neutron tube reactor subcriticality measurement system and method. The system consistsof: a neutron tube for neutron generation, a neutron tube control box for neutron tube control, a second industrial control computer for transmitting set parameters controlling the neutron tube to theneutron tube control box, a first neutron detector and a second neutron detector symmetrically disposed on the reactor, a collection card for collecting a second analysis signal emitted by the firstneutron detector and a third analysis signal emitted by the second neutron detector, and a first industrial control computer for spectral analysis of the analysis signals. The collection card is alsoin connection with the neutron tube control box to output a modulation signal to the neutron tube, and at the same time the modulation signal is fed back as a first analysis signal to the first industrial control computer to participate spectral analysis. The modulation signal is used for controlling the neutron tube in random generation of neutrons. The system realizes utilization of the neutrontube to replace a californium source ionization chamber to drive the reactor to do noise process measurement.

Description

technical field [0001] The invention belongs to the technical field of reactor subcriticality measurement, in particular to a neutron tube reactor subcriticality measurement system and method. Background technique [0002] For subcritical reactors, a very important issue is the measurement of subcriticality. In the measurement of subcriticality, there are multiple methods to measure subcriticality, and the use of noise analysis method to measure subcriticality is one of the measurement methods. Of which californium source ( 252 Cf)-driven spectral noise analysis technology was proposed by Oak Ridge National Laboratory in the 1970s. [0003] my country's californium source ( 252 In the study of the spectral noise analysis measurement method driven by Cf), the China Atomic Energy Research Institute and the Beijing Nuclear Instrument Factory jointly developed a californium source fission ionization chamber, and used the developed californium source fission ionization chamber...

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Problems solved by technology

[0005] However, using the californium source-driven spectral noise analysis technique to measure the subcriticality also has its disadvantages: firstly, the californium source, as an isotopic neutron source, has a certain degree of radioactivity, so the californium source fission ionization chamber needs to be monitored during storage and movement. Radiation shielding is also inconvenient when making it; at the same time, the californium source itself has a decaying half-life, so the intensity of the neutron source continues to decrease after a period of time, and the neutron intensity produced cannot be adjusted; the price of the californium source is also very expensive

The existence of these disadvantages all limit the use and promotion of this method

[0006] As a kind of neutron source for accelerators, neutron tubes have no radioactivity during storage and moving, and do not require radiation protection. At the same time, the intensity of neutron sources can be adjusted during work, and there is no such The same problem as the californium source fission ionization chamber, that is, the strength of the californium source has obvious attenuation after a period of time, and the current neutron tubes generally cannot directly measure and count the number of neutrons emitted.

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