Hundreds of nuclear security experts stressed the dangers of nuclear threats in Seoul and discussed a variety of solutions for overcoming challenges in securing fissile materials two days before South Korea kicked off the 2012 Seoul Nuclear Security Summit.

The nine-hour Seoul Nuclear Security Symposium began with a keynote speech by Graham Allison, director of the Belfer Center for Science and International Affairs at Harvard University, who wrote “Nuclear Terrorism: The Ultimate Preventable Catastrophe.”

He put a map of Seoul onto the screen, raising the question of “what if” the densely populated city comes under attack by nuclear terrorists.

Allison stressed that the scenario was “plausible” and it could be a direct threat to South Koreans.

If terrorists smuggle a small amount of fissile materials into South Korea, assemble them to make so-called “dirty bombs” and detonate them in an important financial district, it will have a “huge” impact on the global financial system, he warned.

In the first round of the session on the current nuclear security status, Frank von Hippel, professor at Princeton University and co-chair of the non-governmental International Panel on Fissile Materials, said a major concern involves the use of nuclear-weapon materials for non-weapon purposes. He said they could be diverted or stolen and used for weapons purposes.

Miles Pomper, senior research associate of James Martin Center for Nonproliferation Studies, said there had been some progress in the last two years in securing, eliminating and consolidating vulnerable nuclear materials.

“States completed 80 percent of their individual commitments,” Pomper said.

However, he added that such progress was not enough, and the Washington Communiqu, which seeks to secure all vulnerable materials by 2014, was not likely to be implemented on schedule.

He called on countries at the Seoul summit to set more ambitious goals in minimizing highly enriched uranium and ratifying the Convention on the Physical Protection of Nuclear Material.

He also urged the states to develop a system that can “bundle together the disparate pieces of nuclear security conventions, rules and standards.”

In the second sessions on nuclear security challenges and solutions, Maurizio Martellini, secretary general of Landau Network-Centro Volta in Italy, said the Seoul summit should also be aware of cyber threats to nuclear reactors and facilities.

“The summit should define the specific human skills required to protect against nuclear cyber terrorism and create internationally recognized standards and certifications,” Martellini said.

Hwang Soon-il, a professor at Seoul National University, proposed that states place all nuclear facilities in a multinational territory with security assurance provided by all member states, citing the Fukushima disaster.

“Fukushima accidents have resulted in a global consensus that spent nuclear fuel is better stored in naturally-cooled dry casks rather than keeping them in water-cooled pools,” Hwang said.

“However, dry casks are vulnerable to terrorist attacks. Therefore, it is proposed to place all nuclear facilities in those areas in a multinational territory,” he said.

Kaoru Naito, president of Nuclear Material Control Center in Japan, said the final version of the Advisory Committee on Nuclear Security’s report, “The Responses to Nuclear Security Issues in view of Fukushima Daiichi Nuclear Power Plant Accident,” came out Wednesday.

He said Japan had a duty to share the lessons learned from the Fukushima accident with the international community to reflect them in global efforts to enhance nuclear security.

By Kim Yoon-mi (yoonmi@heraldcorp.com)