How the £10bn Wylfa Newydd power station will manage and dispose of nuclear waste is the subject of a consultation.
It will look at how the station on Anglesey will discharge, transfer and dispose of radioactive material.
Natural Resources Wales (NRW) is asking for views on Horizon’s application for an environmental permit.
This only deals with radioactivity and will only be granted if NRW is “wholly satisfied” with the arrangements.
He said it would only issue a permit if it was wholly satisfied the plans prove they will operate safely, without harming the environment or communities.
The old Wylfa plant stopped generating electricity after 50 years at the end of 2015. Its replacement, next door, would operate for 60 years and generate electricity for around five million homes.
But there is opposition to nuclear power and the waste it creates, while there are also planning and cost hurdles – the “strike price” for the electricity generate – to overcome before Wylfa Newydd can get the go ahead.
Read more at Wylfa Newydd nuclear waste permit consultation starts