On-line Uranium Concentration Measurement System Based On Gamma Absorption Technique In High Gamma Background

Nowadays,energy shortage is an urgent problem for all the countries in the world.As a safe、efficient and environmentally way to obtain energy,nuclear energy is an effective way to understand the problem of global energy shortage.As the main fuel of nuclear reactor,the demand of nuclear fuel will grow.However,there is a serious shortage of uranium resources which can be exploited in China.Most of the uranium fuel used in nuclear power plants is imported from abroad,which will affect the healthy development of China’s nuclear power industry.Due to the operating characteristics and safety requirements of nuclear reactors,nuclear fuel is not as depleted as fossil fuels.The energy conversion rate of nuclear fuel is low,and the spent fuel has a high level of radioactivity and toxicity,nuclear reprocessing technology is an effective way to solve the problem.The main purpose of nuclear reprocessing technology is to separate the uranium、plutonium and sliver elements from spent fuel.The recycling of uranium and plutonium as products returned to the nuclear industry to improve the efficiency of the use of nuclear fuel.Purex method is often used in factories,extraction of U and Pu in pipeline by TBP.Therefore,the concentration of uranium in the process pipeline is very important for the process control.In order to monitor the concentration of uranium in the process,it’s necessary to design a system for measuring the concentration of uranium.This is an on-line uranium concentration measurement system based on gamma absorption technique.In the field niche,when the gamma ray emitted by the 241 Am source passes through the sample cell,the rays interact with the uranium in the pipeline,and some of the gamma rays are absorbed.On the other side of the process pipeline,NaI(Tl)crystal detector detects gamma rays will be reduced.Outside niche,the signal detected by the probe is transmitted to the digital multichannel spectrometer,the control panel controls the sampling system with the solenoid valve and the electric baffle.Through the amplifier,analog-to-digital conversion,digital pulse shaping and amplitude extraction,the spectrum data is processed and displayed by an industrial computer through a CAN bus data box,In practical application,when the process pipeline through the strong gamma radiation of “hot uranium”.After strong gamma radiation,NaI(Tl)crystal count will drown out the gamma rays emitted by 241 Am,and the software is unable to calculate the uranium concentration.Replace the detector 50 mm in diameter 50 mm thickness of NaI(Tl)crystal to the thin crystal 50 mm diameter 1mm thickness.High energy gamma rays directly through the crystal,the probe can accurately measure the gamma ray of the 241 Am source after gamma absorption.After testing,the RSD of the measurement system is 0.0294%,Continuous measurement for 10 hours,the instrument has good stability.The relative error between the on-line analysis and the laboratory analysis is about 3.254%.After half a year of field measurement,on-line system be able to monitor uranium concentration in pipeline for a long time and long distance...