Atmospheric input of 137Cs and 239,240Pu isotopes in Korea after the Fukushima nuclear power plant accident

• Atmospheric samples have been collected for the analysis of 137Cs and Pu isotopes.
• Current levels of 137Cs and 239,240Pu in Korean rainwater are reported.
• The monthly depositional fluxes of 239,240Pu and 137Cs are evaluated.
• The Fukushima Daiichi NPP accident caused no significant impact in Korea.

Caesium isotopes (134Cs and 137Cs) and 239,240Pu in rainwater and dry deposition have been analyzed by Korea Research Institute of Standards and Science (KRISS) since the Fukushima nuclear power plant (NPP) accident in March 2011. The concentrations of 239,240Pu and 137Cs in the rainwater are 2.6±1.0 to 15±3 µBq/kg and 0.01 to 0.36 mBq/kg, respectively. The concentrations are concordant to those observed before the Fukushima NPP accident, on the other hand, the monthly depositional flux of 239,240Pu and 137Cs are much lower than the amounts observed after Fukushima NPP accident and in Monaco in 1998–2001. This confirms that the Fukushima NPP accident caused no significant impact in Korea.