“…The 14 C concentrations in the 2010 ring from Namie and the 2009–2010 rings from Shimotsushima and Yamakiya are consistent with the SIL values, again indicating the exponential decline in the global atmospheric 14 CO 2 activity. On the other hand, like the enhancement in 14 C prior to the accident, observed in Okuma tree rings9, the elevated 14 C in the 2009 rings from Futaba, Takase, Ogaki and Namie, and in the 2010 rings from Futaba, Takase and Ogaki, confirm the existence of 14 C discharges during routine reactor operations, which is consistent with observations at other nuclear sites using similar technologies3. It should be pointed out that the 14 C activities in 2009 and 2010 in the Futaba sample are higher than those observed in the Okuma sample by 8% and 6%, respectively.…”