The concentrations and activity ratios of the radionuclides aroundthe nuclear facilities located in Taejon were determined. The concentrationsand activity ratios of uranium isotopes in the downstream decreased with increasingdistances from the point of discharge and reached the reference value after4 km. The concentrations of uranium isotopes in the brook around LWR fuelfabrication facilities were lower than those in the downstream around HWRand LWR fuel fabrication facilities, while the activity ratios of 234U/238U in the brook were higher than those in the downstream.The concentrations of uranium isotopes in the ground water measured quarterlywere variable depending on the sampling time. The concentrations of the grossalpha of airborne particulates collected around the nuclear facilities werefound to be in the narrow range of 0.02 to 0.10 mBq/m3 with a meanvalue of 0.05 mBq/m 3 . Both the concentrations and activity ratios of 137Cs, 239,240Pu and 90 Sr around the nuclearfacilities were not very different from the worldwide fallout. The concentrationsof uranium isotopes in the soil samples around the nuclear facilities werevery close to natural background levels.