Spatiotemporal distribution of the atmospheric 14C around Ningde NPP.

ABSTRACT

In this paper, the sampling and monitoring methods of atmospheric 14C around Ningde NPP were presented, and the variations and trends during 2013-2021 were statistically analyzed and comparatively studied with worldwide reported values around NPPs. Meanwhile, the correlation study with the gaseous effluent emission amount from Ningde NPP was analyzed, and the spatial distribution of the atmospheric 14C around Ningde NPP was simulated with the atmospheric release based on the long-term meteorological parameters with the plume diffusion model. It was shown that the average specific activity of atmospheric 14C at each sampling site ranged from 229 to 230 mBq/gC, and the weak evidence of influence on the nearest sampling site from the release of the NPP could be observed. Seasonal variations of 14C specific activity were analyzed, and it was shown that, except for the site 1.7 km from the NPP, the specific activity of the atmospheric 14C was higher in summer and autumn and lower in winter and spring. Besides, it was shown that the excess 14C for long-term monitoring results around the NPP was consistent with the simulated values on the order of magnitude.