Zero-Emission Nuclear Power Production Credit Act of 2021 This bill allows a new business-related tax credit through 2031 for the production of electricity from zero-emission nuclear power. It also allows an election for direct payments of such credit and requires a recapture of the credit for contractors who pay their laborers or mechanics less than the prevailing wage rate. Contractors must ensure that at least 15% of their work force is composed of qualified apprentices. The bill requires the Government Accountability Office to report on the effectiveness the tax credit.