Study On The Performance And Application Of Standard Facility Of Radon Exhalation Rate

More and more attention have been payed to the hazard of radon and its daughters.The measurement of the radon exhalation rate is an important method for investigation of source term of radon concentration exceeding.It has been widely used in indoor,mining,underground engineering,tailings and other places.Domestic and foreign countries have introduced relevant standards for the measurement of the radon exhalation rate,but they have not given a standard method and calibration method for measuring the radon exhalation rate.The radon laboratory of the University of South China has successfully developed the standard facilities of radon exhalation rate.However,there is a lack of strict quality control in use,and no regulation of verification have been established for various types of radon exhalation rate measurement methods.,which has certain impact on the accuracy of the device test results.Therefore,it is very necessary to strictly measure the performance parameters of the standard facilities of radon exhalation rate and establish the regulation of verification for the radon exhalation rate measuring instruments.The result of value determination of the standard facility of radon exhalation rate is 1.64±0.05Bq·m-2s-1,The overall Inhomogeneity was 10.4%,the local Inhomogeneity was less than 9.1%,The short-term instability(within 24 hours)was 6.4%,the daily instability was 1.9%,and the long-term instability was 7.9%.The radon exhalation rate is not affected by environmental factors such as temperature and humidity,but it is negatively related to the pressure rise and fall.According to the results of the performance parameters research and the selection of appropriate reference values for different measurement methods and measurement time during the calibration,the environmental correction coefficient k was introduced.And correct the reference value according to the different sampling time.;in addition,analyze the parts that may cause errors in common measurement methods and reduce the influence of human factors on the experimental results.In order to solve the problems existing in the method for evaluating radon prevention effect of radon resistance materials,a new set of evaluation methods was established.Evaluation radon prevention effect of radon resistance materials by direct measurement and indirect measurement,moreover,the radon permeability coefficient of the material can be measured,and different kinds of radon resistance materials can be compared.Through the research of this paper,we have more detailed reference data about the value of standard facility of radon exhalation rate.provide the suggestions for calibration of different radon exhalation rate measuring instruments and devices to make the result accurate and reliable.At the same time,a new evaluation method for radon prevention effect of radon resistance materials was established so that the standard facility of radon exhalation rate could better serve the reliable research.