¹⁴CH₄ Emissions from Nuclear Power Plants in Northwestern Europe

We measured the 14 C content of atmospheric methane at a 200-m-high sampling station in The Netherlands. Combined with trajectories and a transport model, it is possible to estimate the 14 CH 4 emissions from nuclear power plants in northwestern Europe. We demonstrate here two different methods of analyzing the data: forward modeling and an inverse method. Our data suggest that the emissions from pressurized water reactors are 260 ± 50 GBq per GW installed power per year, ca. 1.6 ± 0.4 times higher than generally assumed. We also find that, in addition to the known nuclear sources of 14 CH 4 (pressurized and boiling water reactors), there are two very strong sources of 14 CH 4 (520 ± 200 and 1850 ± 450 GBq yr −1 , respectively), probably two test reactors near the sampling station.