Study On On-line Monitoring Technology For Instrumentation In Nuclear Power Plant

On-line monitoring technology is to obtain data from the instrument channel or plant computer during the plant operation,and to analyze the data by computer off-line processing,in order to get the performance of instrument channel or equipment in nuclear power plant.As long as development of nuclear power,more and more utility owners begins to realize the significance of on-line monitoring for instrumentation.Among various monitoring techniques,online calibration technique with a pretty much efficient strategy of instrument channel detection,rather than regular calibration operation in a certain extent,reduces maintenance cost and personnel radiation exposure and improves reliability of instruments and prevents unscheduled plant shutdown.But in China this technology is still in the early stage.In meantime,through tracking international trend of on-line monitoring technology development,this thesis also describes principles of technology application,proposes online monitoring methods applicable to temperature elements and pressure(or differential pressure)transmitters in nuclear power plant.Specifically,online monitoring for platinum resistance detector or thermocouple is reached by using cross calibration with averaging algorithm,and that for pressure or differential pressure transmitter is by way of non-redundant instrument channel analysis techniques based on the real plant data.Two kinds of empirical model algorithms,Auto-associative Kernel Regression(AAKR)and Auto-associative Multivariate State Estimation Technique(AAMSET),are used for modeling which is verified by real operation parameters of domestic nuclear power plant.By analyzing and comparing the data of the two models,the analysis of the model performance is given.It is concluded that AAKR is a relatively accurate and relatively easy to implement method.During above process,applicability of the technology is analyzed by instrument channel uncertainty calculation theory.Based on the comparison of online monitoring technology and traditional calibration technology,the implementation process of on-line monitoring system is presented.