"The Pacific Ocean is a major repository of plutonium released from atmospheric tests of nuclear weapons. Both global fallout from plutonium released to the stratosphere as well as close-in fallout from the troposphere contributed to the present levels of plutonium in seawater and sediment of the Pacific Ocean." [2001: https://www.sciencedirect.com/science/article/pii/S156948600...]

Now that is fresh. NPR's article fails to tell us how we can tell 'space' Pu from 'test' Pu. It further confounds the issue by calling it 'freshly Made Plutonium From Outer Space' then stating that fresh means 'arrived on Earth within the last 10 million years'. Bad science article.