https://www.cyfoethnaturiol.cymru/permits-and-permissions/non-nuclear-radioactive-substance-sites/apply-to-vary-change-a-permit-for-a-radioactive-substances-site/?lang=cy
Cyfoeth Naturiol Cymru / Cais i amrywio (newid) trwydded ar gyfer safle sylweddau ymbelydrol
Apply to vary (change) a permit for a radioactive substances site. How to apply to vary your radioactive substances permit.