The Reactor Accident at Chernobyl': Identification of Radionuclides in Fallout in Niigata City

Abstract

The fallout caused by the accident of Chernobyl' nuclear reactor has been monitored in Niigata City (April 30-June 3, 1986) . Twelve nuclides (¹³¹I, ¹³²I, ¹²⁹Te, ^129mTe, ¹³²Te, ¹³⁴Cs, ¹³⁶Cs, ¹³⁷Cs, ¹⁰³Ru, ^99mTc, ¹⁴⁰La, ¹⁴⁰Ba) were identified in aerosol samples. The same nuclides plus ⁷Be were identified in rain-water. Gaseous and particle-bound ¹³¹I were separately trapped on a glass filter and a charcoal filter, respectively. Results indicate 50-60% of atmospheric ¹³¹I is gaseous and the rest is particlebound. Chloroform extraction of rain-water revealed that 40-60% of ¹³¹I in the rain-water sample exists in the form of IO₃^- and ¹³¹IO₃^- (¹³¹IO₄^-) /¹³¹I^- seemed to increase with the lapse of time after the accident.