Cape Town daily The Cape Times reported on Wednesday that the cost of decommissioning the proposed nuclear power stations will add several hundred billion rand to the bill, the study shows.
The study by Steve Thomas, of the UK's University of Greenwich was commissioned by the Legal Resources Centre.
The study claims that the massive expenditure would have no effect on the country's current power crisis as the plants were unlikely to make a massive contribution to the national grid before 2020.
And while taxpayers will foot the bill, they will not have a chance to have their say on the matter, according to the Cape Times report.
"The risk of such a large programme is that for the next 10 to 15 years, SA will be locked into a nuclear programme that will have absorbed many of the available resources but which will have come to nothing, or will have produced only one or two 'white elephants'", Thomas said.
The newspaper quoted Mineral and Energy Department spokesperson Sputnik Ratau, saying that the nuclear plan "had been in the pipeline for a long time. Not everything stops because the integrated energy plan has not gone through".
Burdened consumers already face a 18% spike in electricity tariffs this year. Eskom last month applied to the energy regulator to consider a 18% hike in tariffs to help fund its R150bn spending plan over the next five years.
Eskom chief executive Jacob Maroga told SABC television then that prices "have to go up".
"We are spending R150bn over the next five years to build new plants and to improve services and all this has to be paid for."
Public Enterprises Minister Alec Erwin confirmed last Friday that local electricity tariffs are likely to keep rising steeply as South Africa tries to fund its massive spending programme to upgrade its power network.
The country has suffered a series of blackouts over the past couple of years as it struggles to keep up with faster economic growth and rising demand for energy that officials say has outpaced supply.
Erwin said about half the funding for these projects would have to come from hiking electricity tariffs and the rest via the capital markets.