Abstract: External radiation personal dose monitoring data can be used as the occupational radiation dose certification received by radioactive workers and has the legal effect. Therefore, the accuracy and reliability of personal dose monitoring and measurement data for external irradiation is particularly important. Personal Dose Monitoring Centre in CNNP Nuclear Power Operation and Management Co.Ltd., obtained CMA (China Inspection Body and Laboratory Mandatory Approval) and the qualification of radiological health technical service institution in 2017. In addition to the center’s internal quality control measures, Centre also attends the annual inspection detection capacity assessment of the national radiological technology agency. This paper analysis the measurement data and uncertainty evaluation based on the 2019 capacity assessment experimental results (qualified) of CNNP. The relative extended uncertainty of the measurement results of each experimental group is about 10%, which proves that the external radiation monitoring and measurement system has a good performance, and ensures the accuracy and reliability of the monitoring data of the individual dose monitoring center.

Key words: external radiation monitoring system, data analysis, measurement uncertainty evaluation