STUK made the decision last week to give the green light for the construction of an underground nuclear waste repository to be carried out by nuclear waste management firm Posiva.
Posiva received permit approval for the project already last year but was required to wait until STUK made sure that all safety issues were taken into consideration, the authority said.
Once complete, the new waste facility will reportedly be able to hold some 6,500 tonnes of depleted uranium.
The used fuel rods will be sealed in copper containers and moved through underground tunnels some 400 to 450 metres under the ground, where the waste will finally be placed in a bentonite-lined disposal pit.
Posiva's construction of the site will be closely monitored by STUK, the agency says, and the repository be put into use sometime during the 2020s.