In 2008 Ontario Power Generation (OPG) sought environmental assessment (EA) approval to build up to four new nuclear reactors at the Darlington site. A Joint Review Panel (with members from the Canadian Environmental Assessment Agency and the Canadian Nuclear Safety Commission – CNSC) held public hearings in 2011. CELA and many other public interest organizations participated in the Joint Review and raised many concerns about:

• the need for, and alternatives to the proposal,
• storage and fate of high level radioactive waste from the new reactors, and
• emergency planning for accidents at the plant to protect the public.

The Joint Review Panel reported to the Federal Environment Minister in 2011 recommending acceptance of the EA. The federal government subsequently accepted the EA in May of 2012. The CNSC license issued in 2012 and valid until 2022, allows only for site preparation. In the meantime, the Ontario government has stated that it will not proceed with building new reactors in Ontario. In June of 2020, OPG applied to renew the site preparation licence beyond 2022.