World leaders will gather in South Korea in March for a summit that will seek to restore confidence in the nuclear industry after the Fukushima disaster in Japan, a spokesman said Monday.

The Nuclear Security Summit in Seoul will be the second since US President Barack Obama inaugurated the forum in Washington in 2010 as a way to strengthen international safeguards and prevent nuclear terrorism.

South Korean official Hahn Choong-hee said the Fukushima accident would loom large over the March 26-27 talks as he outlined the agenda at a news conference in Hong Kong.

The disaster triggered by a tsunami has damaged confidence in nuclear energy, leading to the shutdown of most of Japan's 54 commercial reactors and Germany's decision to phase out nuclear power by 2022.

But Hahn, the spokesman for the summit, said the worst atomic accident since Chernobyl had come amid a "nuclear renaissance" in the form of growing demand for the kind of reliable and renewable energy that nuclear reactors provide.

"There is quite strong demand for electricity and energy, and concern about climate change," he said, referring to the continued popularity of nuclear energy despite the safety fears.

The 50 world leaders who are expected to meet in Seoul will discuss "more reinforced measures ... to give confidence" to the nuclear industry, he said.

The Fukushima Daiichi nuclear power plant suffered explosions and fires after an earthquake and resulting tsunami crippled its cooling systems on March 11 last year, releasing radiation into the environment.

Tens of thousands of residents around the site in northeastern Japan were forced to evacuate their homes, and some parts of the exclusion zone are expected to be uninhabitable for decades.

Hahn said the accident highlighted the potential threat of a terrorist attack aimed at sabotaging a nuclear plant's essential systems, such as its power supplies, pumps and cooling processes.

"What if that situation, such as the malfunction of pumps ... could be done by intentional terrorists?" he asked.

Threats to the security of nuclear material posed by instability in the Middle East would also be on the summit's agenda, as well as ongoing efforts to stop terrorists building a "dirty bomb" with radioactive material.

Iran's alleged nuclear weapons programme and North Korea's atomic bombs are being handled through other diplomatic forums and representatives of those countries will not attend the summit, Hahn said.