Development Of New Meter Meter

The control of the pressurized-water reactor’s power is transited by accommodatingthe control rod and the primary circuit’s boron concentration. Monitoring core boronconcentration is vital in the reactor start-up, power operation and cold-refueling. Theboric acid is needed in cooling water used as reactor’s primary circuit to achievereactor’s compensation control so as to flatten the reactor power distribution andincrease burn-up; as well as in the periods of reactor shutdown, refueling and overhaulto maintain the active area in the sub-critical state for a long time.Therefore, in orderto ensure safe operation of the reactor, it requires real-time continuous monitoring ofthe concentration of boric acid in primary circuit. Boron meter, a device includingon-line and off-line types and dedicated to monitoring the boron concentration, whichis essential to the safe, stable and economical operation of nuclear power plant.After a systematic analysis of the advantages and disadvantages of on-line andoff-line boron meters in service in China, this paper presents a new on-line boronmeter monitoring system with a simple structure, easy installation, fast response, andhigh accuracy,which consists of primary and secondary instruments.This paper, usingthe primary instrument as the research object, studies the detection device, theamplifier circuit and calibration. The research results and detailed contents are asfollows:(1) The paper analyzes and designs the material, structure, size and surface doseshielding of all parts of its detection device, in which the MCNP, Geant4and otherMonte Carlo simulation and experimental verification methods are used, and fromwhich a practical detection device with high measurement sensitivity, easy installation,low surface dose rate and counter check function is worked out.(2) This paper analyzes and develops the amplifier circuit by putting thepre-amplifier and the main amplifier on one PCB,to put it more specific, combing thecharge-sensitive preamplifier with the general inverting amplifier to work out asecondary voltage amplifier circuit, and then using the push-pull power amplifiercircuit to amplify current. The designed circuit proves simple in structure and high inoutput signal-to-noise ratio upon the PCB board experimental testing, so it meets the usage requirements.(3) This paper also analyzes the necessity of calibration tests temperature,performance counter, floor curves, threshold pressure curve,presents the boric acidtitration method, designs calibration loop structure, and proposes specific method ofcoefficient calibration.