Measurement system for measuring neutron flux in strong radiation and high temperature conditions

Abstract

The invention relates to a measurement system for measuring a neutron flux in strong radiation and high temperature conditions and belongs to the technical field of nuclear reactor engineering. The measurement system mainly consists of a thermal neutron sensitive detector, a fast neutron sensitive detector, a thermal neutron absorber, two amplifiers, a data acquisition module and a neutron energy spectrum analysis module, wherein the thermal neutron absorber is wrapped around an outer surface of the fast neutron sensitive detector, signals detected by the thermal neutron sensitive detector and the fast neutron sensitive detector are respectively output to the two amplifiers, signals received by the amplifiers are processed and output, signals output by the amplifiers are subjected to digital processing operation via the data acquisition module, digitized signals are output by the data acquisition module, the neutron energy spectrum analysis module is used for subjecting received digitized signals to neutron energy spectrum analysis, neutron energy spectrum data can be obtained, and the neutron flux can be calculated based on the neutron energy spectrum data. The measurement system disclosed in the invention is advantaged by light weight, easy-to-install property, strong mobility, small measurement error and the like.

Description

technical field [0001] The invention relates to a measurement system for measuring neutron flux, in particular to a measurement system suitable for measuring neutron flux under strong radiation and high temperature conditions, and belongs to the technical field of nuclear reactor engineering. Background technique [0002] The current measurement of neutron flux in nuclear power plants is based on the measurement of thermal neutrons, focusing on the contribution of the burnup of the thermal neutron energy region to power generation, and the contribution of higher neutron energy can be ignored, that is, the nuclear fuel consumed by the thermal reactor is 235 U. At present, commercial nuclear power plants usually use thermal neutron sensitive detectors to measure the power of thermal piles. [0003] For the fourth-generation fast neutron reactor, it is mainly a reactor that causes a fission chain reaction by fast neutrons, and the nuclear fuel burned is 238 U or 232 Th or ac...

AI Technical Summary

Problems solved by technology

If a detector sensitive to thermal neutrons is used for measurement, the energy of fast neutrons must be slowed down before the measurement can be performed. This will result in different regions and different neutron moderation capabilities, resulting in different measurement results, which will inevitably lead to measurement The large deviation of the result

In addition, the power measurement method for fast reactors is still immature, in the experimental stage, and has not yet reached the engineering stage

[0004] In the article "Experimental Research on Neutron Spectrum Measurement of China Experimental Fast Reactor" published in the 2013 (S1) Journal of Atomic Energy Science and Technology, the activation method was used to measure the neutron spectrum of the sodium-cooled fast reactor. The neutron integration measurement is carried out on various activation sheets of the source, and the neutron energy spectrum is obtained by spectrum analysis, but there is no way to give information such as online neutron flux

Chinese patent application numbers CN201210332734.0 (2013) and CN101419290 (2009) both use thermal neutron sensitive detectors, but cannot meet the fast neutron energy spectrum online analysis of fast reactor power

However, there is only one kind of detector used in these detection methods, and it is impossible to obtain energy spectrum information.

In the article "Optimization Calculation of ITER Neutron Flux Monitor" published in the Journal of Nuclear Electronics and Detection Technology in 2012, although it is recorded that the dual-fission chamber detector and the moderator / shielding layer that wrap the detector are composed of There are two types of detectors, but they are compensation type, and online energy spectrum analysis cannot be performed, because the moderator is made of polyethylene material, which cannot meet the conditions of use in high temperature environments

[0006] It can be seen that the technical solution of the above-mentioned public report is to directly provide the size of the neutron flux through the reading of a single counter or multiple counters, which will inevitably bring about a large error

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