South Korean prosecutors said Tuesday they had charged 32 people with corruption involving the state nuclear power agency and its contracts with suppliers.

Among those charged are 23 Korea Hydro and Nuclear Power officials and engineers accused of taking bribes, said the prosecutors' office in the southeastern city of Ulsan.

They allegedly pocketed a total of 2.22 billion won ($1.94 million) for helping suppliers clinch lucrative deals with the agency.

A 52-year-old senior engineer at the country's oldest nuclear plant at Gori alone received 450 million won, prosecutors said.

Seven employees of supply firms and two brokers were also arrested and charged with providing bribes or arranging them.

"The case confirmed structural corruption such as bribery, bid-rigging and favours at one of the country's major state firms," prosecutor Koo Bon-Jin told reporters.

The probe came amid concern over the safety of 21 nuclear reactors that meet about 35 percent of South Korea's electricity needs, following last year's nuclear disaster in Japan.

In February the Gori reactor, built in 1978 near the southern city of Busan, briefly lost mains power and the emergency generator failed to kick in. The incident resulted in no radioactive leaks but sparked an uproar over safety.

In May, five engineers at Gori were charged with trying to cover up the potentially dangerous power failure.

Earlier in May a businessman was jailed for three years for supplying potentially defective parts to the Gori plant.