A Three-dimensional Digital Research On Monitoring Cladding Damage Of Fuel Element Of Chinese Pulse Reactor

The thesis makes a research on three-dimensional fuel element cladding damage digital monitor with delayed neutron monitoring as the major method and generalγand fission gas monitoring as the minor method. The monitor includes MCU's host system and three branches: BF3 counter tube slip, GM counter tube slip and plastic scintillator detector slip, which are monitored by delayed neutron, generalγ, and fission gas respectively. The three monitoring branches work together at the same time and display at real-time on-line corresponding counting rate of delayed neutron, generalγ, and fission gas respectively, hence, realization of state judgment and intelligent alarm. What has been introduced above is a three-dimensional intelligent monitor with delayed neutron, generalγ, and fission gas as its monitoring methods.The thesis first elaborates research purpose and significance of three-dimensional fuel element cladding monitor, then makes an analysis of working principles of three separate monitoring ways and their advantages and disadvantages. Then it explains research principles and methods of integrated three-dimensional cladding monitor's reducing false alarm and missing alarm, making a statistic of fluctuation processing and alarming intelligently. Then the process of monitor development is explained in detail, from the angle of the software and hardware of the monitor respectively.The thesis consists of six parts, explaining the development process of China pulse reactor fuel element cladding damage monitor. Part one gives a general account of research purpose and significance as well as research condition at home and abroad. Part two explains the principles and methods of three-dimensional cladding monitor from theory. Part three elaborates in detail hardware circuit design of the monitor from the angel of hardware design. Part four makes an analysis of design basis of program model from the angel of software. Part five explains Test procedure of the monitor. Part six is a conclusion which makes an analysis of underlying problems and research limitation as well further study.The characteristics of the project lie in the following aspects: three-channel pulse frequency real-time display and corresponding channel state real-time judgment, automatic circle of floating alarm threshold, the choice of threshold (fixed or floating) state, three-level intelligent alarm, setting and revision of relevant parameters like time, checkup of historical data, recent alarm condition and threshold.