O gofio'r safle y daeth y deunydd ohono, sef Hinkley Point C, cynhaliodd Canolfan Gwyddorau'r Amgylchedd, Pysgodfeydd a Dyframaethu (CEFAS) asesiad ymbelydrol fel rhan o broses cloriannu'r ceisiadau, ac ar ôl ymgynghori ag arbenigwyr (gan gynnwys y prif reoleiddiwr niwclear yn Asiantaeth yr Amgylchedd), ni fynegwyd unrhyw ofidiau ynghylch y lefel radiolegol.
Given the location of the source site, at Hinkley Point C, a radiological assessment was undertaken by the Centre for Environment, Fisheries and Aquaculture Science (Cefas) as part of the determination process for the marine licence, and following consultation with experts (including the lead nuclear regulator at the Environment Agency), no concerns were raised regarding the level of radiological contamination.