FirstEnergy has applied for Nuclear Regulatory Commission (NRC) approval for renewal of the Davis-Besse Nuclear Power Station operating licence.
The 908MW facility near Toledo, Spain, is licensed to operate until 2017 and the renewal will extend operations for another 20 years through to 2037.
In March 2010, inspectors found cracks in equipment and the plant had to temporarily close for refuelling and safety inspections.
The NRC required the utility to replace a major component by October 2011, three years earlier than the utility had planned to remedy the problem.
For the review, the commission will conduct several on-site audits of the plant's structures and components and carry out an environmental survey that would determine whether continuing operations would have any adverse impact on local surroundings.