Abstract: Based on monitoring data of ⁷Be, ⁴⁰K, ⁶⁰Co, ¹³¹I and ¹³⁷Cs in the ambient air around the China Nuclear Power Institute from 2015 to 2017, the effective doses of residents near the monitoring points of comprehensive building, Nanba Trade Union and Mucheng water plant were roughly estimated. The results showed that the average annual intake of ⁶⁰Co, ¹³¹I and ¹³⁷Cs as well as the induced annual effective doses decreased with the increase of the distance from the nuclear facilities; the average annual intakes of adults, teenagers, children, infants and newborns of residents near the comprehensive building by inhalation of ⁷Be, ⁴⁰K, ⁶⁰Co, ¹³¹I and ¹³⁷Cs are 29.25, 26.48, 20.16, 11.49 and 6.79 Bq/a, respectively; the annual effective doses of teenagers, children, adults, infants and newborns of residents near the comprehensive building caused by inhalation, immersion in the air and ground deposition of ⁶⁰Co, ¹³¹I and ¹³⁷Cs are 133.58, 130.98, 128.61, 120.20 and 118.61 nSv/a, respectively; the dose fraction caused by ⁶⁰Co reached 95.6%, followed by ¹³⁷Cs; the dose fraction caused by surface deposition reached 54%, followed by inhalation; the maximum effective dose caused by ⁶⁰Co, ¹³¹I and ¹³⁷Cs in the youth group of residents near the comprehensive building is 133.58 nSv/a, but this effective dose is only less than 1‰ of the target value of the evaluation dose (0.25 mSv).It can be concluded that ⁶⁰Co, ¹³¹I and ¹³⁷Cs have little influence on the ambient air of the nuclear base under normal operating conditions.

Key words: ⁶⁰Co, ¹³¹I, ¹³⁷Cs, nuclear base, dose evaluation