A constant concentration tritium flow generator system and method

Abstract

The invention discloses a constant concentration tritium airflow generator system and method. The tritium airflow generator system includes a closed circulation loop, and the closed circulation loop is sequentially provided with a tritium airflow generator, a tritium gas monitor to be calibrated and a tritium airflow circulation pump , the closed circulation loop is also provided with a temperature control unit that cooperates with the tritium airflow generator, temperature sensors are installed at the inlet and outlet of the temperature control unit, and pressure sensors are installed at the inlet and outlet of the tritium air circulation pump. A hygrometer is arranged between the temperature control unit and the tritium gas monitor to be calibrated, and a nitrogen gas storage connected to the tritium flow generator is also included. The nitrogen gas storage is used to provide dry nitrogen for the closed loop circuit. The invention solves the problem of traceability of the value of the airborne tritium monitor, and can realize accurate calibration of the airborne tritium monitor. It can realize the monitoring of airborne tritium in large-scale nuclear power plants of nuclear facilities, military isotope production reactors, military isotope content test sites, and military isotope packaging and use sites.

Description

technical field [0001] The invention relates to the field of radiometric calibration, in particular to a constant concentration tritium flow generator system and method. Background technique [0002] At present, the calibration of tritium gas monitors usually adopts the principle of bubbling method to design a set of standard device of tritium air flow generator, so that the dried air with a certain flow rate is bubbled into the tritium-containing water at constant temperature to generate saturated tritium air flow, and then let The tritium gas flow passes through the tritium gas monitoring instrument, and finally a condensation recovery device is installed at the end to quantitatively analyze the recovered tritiated water, and the activity concentration of the tritium gas flow during the bubbling process is reversed to realize the calibration of the tritium gas monitoring instrument. However, due to the existence of the isotope fractionation coefficient (the ratio of the ga...

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Problems solved by technology

However, due to the existence of the isotope fractionation coefficient (the ratio of the gaseous tritium bubbling out of the bubbler to the activity concentration of liquid tritium in the bubbler during the bubbling process) and less than 1, the activity concentration of the bubbling tritium stream It is not constant. As the bubbling process continues, the activity concentration of the bubbling tritium gas flow will gradually increase, and the quality of tritium water in the bubbler will gradually decrease. After a certain period of time, the saturated tritium gas flow cannot be bubbling, and the bubbling needs to be stopped. Soaking and re-adding tritium water cannot meet the requirements of long-term experiments

Dry air materials are usually dried with molecular sieves and silica gel as a dryer, which cannot guarantee absolute dryness of the air, which affects the accurate calibration of the tritium gas monitor

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