SEOUL (Reuters) - South Korea said on Friday it will start to construct two new nuclear power plants in 2017 at the earliest and another two by 2022, making a total of 11 new nuclear plants planned by 2024.

The new plants come as public trust in nuclear power in South Korea, the world's fifth-largest user of the energy source, has been undermined by a 2012 safety scandal over the supply of reactor parts with fake security certificates, along with the 2011 Fukushima crisis in neighbouring Japan.

In January, Seoul formally adopted a lower target for nuclear power as a proportion of its energy mix, but still plans to add 11 more nuclear reactors by 2024 to the 23 that currently supply a third of the country's power. Last week the nuclear watchdog approved a new reactor.

The Office for Prime Minister's Secretariat and energy ministry said the government agreed with the county of Uljin to add Shin Hanul No.3 and No.4 nuclear plants by 2022.

"Nuclear power is an unavoidable choice if we consider poor natural resources, economic structure centring manufacturing and duty to reduce greenhouse gas emission," Prime Minister Chung Hong Won said in the statement.

Another statement from the government offices said the county of Yeongdeok had agreed to have two plants by 2012.

As compensation for the nuclear power plants, the government via reactor operator Korea Hydro and Nuclear Power Co Ltd will provide a total of 1.5 trillion Korean won (S$1.75 billion) to Yeongdeok for 60 years, and 280 billion won to Uljin to improve the services like roads, schools and hospitals in the remote communities, the statements noted.

Korea Hydro and Nuclear Power, is fully owned by state-run Korea Electric Power Corp.

S.Korea's nuclear reactor status: http://link.reuters.com/qyx92w