South Africa intends to select this year an international partner to build a series of nuclear power reactors that would end the regular electricity blackouts that have hobbled economic growth, the energy minister told parliament Tuesday.

Five nations -- Russia, France, China, the United States and South Korea -- have been chosen to compete for the controversial contract to build eight nuclear reactors worth up to $50 billion (45 billion euros).

"We will commence with the actual nuclear procurement process in the second quarter of this financial year to select a strategic partner or partners in a competitive, fair, transparent and cost effective manner," Energy Minister Tina Joemat-Pettersson said.

"We expect to present the outcome of this procurement process to cabinet by year end."

South Africa has one nuclear power station but relies heavily on coal for electricity generation by the state-owned power firm Eskom.

The company has been struggling to meet electricity demand, and rolling blackouts have become a feature of daily life, crimping economic growth.

The reactors are expected to add 9,600 megawatts of generating capacity in Africa's most industrialised economy, with the first unit to be ready 2023.

They would add nearly a third to the country's current capacity of 30,000 megawatts.

The project has been attacked by critics for a range of reasons -- from environmental concerns to fears that the cost could cripple the economy and that the procurement process could be open to corruption.

"South Africa has signed various inter-governmental agreements or IGAs, laying the foundation for cooperation, trade and exchange for nuclear technology as well as procurement," Joemat-Pettersson said.

"These agreements describe broad areas of nuclear cooperation and they differ on emphasis, based on the unique needs of each country."

South Africa has started a skills development programme and has already sent 50 nuclear trainees to China with plans for another 250 in the future, she said.

Russia has offered five new scholarships at master's degree level in nuclear physics this year, while South Korea has a standing programme to train South African students in masters programmes in nuclear engineering.

A row erupted in September last year when Russia's atomic energy agency appeared to announce that it had won the nuclear power contract, prompting allegations that President Jacob Zuma's government had dodged procurement rules.

But Pretoria insisted at the time that the Russia deal "initiates" the "procurement" phase of the project and that other countries would be given a chance to bid.