Zero-Emission Nuclear Power Production Credit Act of 2021 This bill allows a new business-related tax credit through 2030 for the production of electricity from zero-emission nuclear power. It also allows taxpayers to elect direct payments of such credit and requires a recapture of credit amounts for contractors who fail to pay their employees the prevailing wage rate. The bill requires the Government Accountability Office to report on the effectiveness of the credit in ensuring grid reliability and on ratepayer savings. Contractors must ensure that at least 15% of their workforce is composed of qualified apprentices unless there is a lack of availability of qualified apprentices in the applicable geographic area.