Abstract: The results of radioactivity monitoring of environmental media such as air, water, representative biomaterial, and soil during 2006 to 2010 were presented. The average concentrations of total α, total β in the air aerosol were 0.1, 0.6 Bq/m³. Total α, total β and ¹³⁷Cs in surface water averaged 101.4, 249.8, 2.4 mBq/L, while corresponding values in underground water and biomaterial were 46.7, 90.4, 2.1 mBq/L, and 0.6, 58.2, 2.2×10^-2 Bq/kg(wet), respectively. In soil, the average levels of total α, total β, ¹³⁷Cs, ²²⁶Ra, ²³²Th and ⁴⁰K were 386, 793, 3.0, 36, 48, 548 Bq/kg(dry), respectively.

Key words: Reactor, Radioactivity monitoring, Environmental media