Local and global trace plutonium contributions in fast breeder legacy soils.

Trace-level plutonium in the environment often comprises local and global contributions, and is usually anthropogenic in origin. Here, we report estimates of local and global contributions to trace-level plutonium in soil from a former, fast-breeder reactor site. The measured Pu/Pu ratio is anomalously low, as per the reduced Pu yield expected in plutonium bred with fast neutrons.