The Fukushima nuclear disaster drove the world to reflect on the nuclear energy industry, but the negative impact won't last long, experts said ahead of the 2012 Seoul Nuclear Security Summit.

Officials from 53 countries and international organizations are scheduled to attend the summit, which will be held on Monday and Tuesday in the capital of South Korea.

Nuclear generation itself is not on the formal agenda, but it will feature heavily at the summit because a great deal of trust in atomic energy was lost as a result of the Fukushima nuclear disaster in Japan last March.

The impact of Fukushima has been far-reaching globally, but it varies from country to country, said Matthew Bunn, an associate professor at Harvard University's John F. Kennedy School of Government.

"The countries that are the largest markets for new nuclear reactors - China, India, Russia, South Korea - are moving ahead. Some countries, such as Germany and Switzerland, have decided to phase out nuclear energy," he said.

The nuclear energy industry would continue to expand, especially in China, said Jasper Pandza, a researcher in the Non-Proliferation and Disarmament Program at the International Institute for Strategic Studies, a think tank headquartered in London.

China, which is not a major user of nuclear energy, suspended work on nuclear plants, including some under construction, after the Japan disaster.

"The Chinese government reevaluated the nation's nuclear safety arrangements after Fukushima, which is really good," said Pandza.

It is not clear when China will restart construction of nuclear plants, but the nation will definitely continue developing nuclear energy because it is clean and can efficiently meet growing domestic energy demand, said Xia Yishan, a senior expert on energy strategy at the China Institute of International Studies.

"However, considering the nation's limited uranium reserves ... I am not sure whether nuclear would be the pillar energy in China," he said.

Almost all countries using nuclear energy have undertaken in-depth reviews of their nuclear safety rules and practices, and many introduced substantial new measures to ensure that reactors are better protected against events such as flooding and loss of power, Bunn said.

"Unfortunately, few countries are drawing similar lessons about improving security - despite the possibility of terrorist attacks, for example, that might destroy both off-site power and back-up power for a reactor," he added.

Preventing nuclear terrorism and discussing radiological terrorism are the main issues at the summit, experts noted.

"The No 1 topic on the agenda of the nuclear security summit in Seoul is how to protect nuclear material that can be used in a nuclear weapon - highly enriched uranium and plutonium - from falling into the hands of terrorists," said Togzhan Kassenova, an associate in the Nuclear Policy Program at the Carnegie Endowment for International Peace, a Washington-based think tank.

Terrorists have also considered sabotage of reactors to cause a Fukushima-scale disaster, or spreading radioactive materials over an area in a so-called "dirty bomb", Bunn said.

If terrorists want to try such radiological attacks, the technical hurdles that they would need to overcome are much lower compared with a nuclear attack, Pandza said.

This is the first time that radiological terrorism is being addressed at the level of heads of governments, according to Pandza.

The Seoul summit, the second of its kind, is the largest in the security field that discusses international cooperative measures to protect nuclear materials and facilities from terrorist groups.

Zhao Shengnan in Beijing contributed to this story.