According to UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) the three Hinkley Point reactors released 3.6GigaBecquerels of radioactive particulates in airborne effluents between 1990 - 1996. Assuming they're all made of Uranium Oxide and are all 1 micron diameter, that's 7118millionmillion particles per year.
The three reactors have been running for a total of 119 years (the A station 35 years; the two B reactors 42 years each). If they have been emitting particles at the same rate that's 282thousandmillionmillion particles small enough to inhale into the deepest parts of your lungs.
Natural Resources Wales has given EdF a licence to dredge 300,000 tonnes of sediment at Hinkley Point and dump it at Cardiff. CEFAS tested the sediment. Guess how many particles they told NRW about. None. But they didn't use a technique that would have revealed them, and when they found evidence of the Uranium daughters (isotopes of Thorium that are the decay product of Uranium) they didn't tell NRW about those either.