In an answer given to a question in Parliament, Treasury economic secretary Justine Greening said Budget proposals for a carbon floor tax would mean suppliers of low-carbon nuclear energy would be in line for a windfall.
Ministers had announced the changes in a bid to cut the amount of polluting fuel used to generate electricity.
Ms Greening said: “The existing nuclear sector is likely to benefit by an average of £50m per annum to 2030 due to higher wholesale electricity prices.”
She added: “The carbon price floor is intended to create economic incentives toward low-carbon electricity generation and away from high-carbon generation.
“All types of low-carbon technologies will be incentivised by the price floor.
“The impact on utility companies’ profitability will depend on the overall composition of their generation portfolios and future investment decisions.”
She said renewable energy firms would be up at least £25m a year better off.