A radiation detection system was inaugurated Wednesday in Shanghai, China's biggest port, as part of joint US-China efforts to prevent smuggling of nuclear materials for weapons or terrorism. The system is meant to provide comprehensive screening as part of the Megaports Initiative, a US Energy Department effort to provide such scanning systems at 100 of the world's biggest ports. Shanghai marks the 40th such port, and the first in China. The need for greater vigilance against illicit transport of nuclear materials became evident after the Sept. 11 attacks on New York and Washington. The US Energy Department's National Nuclear Security Administration faced criticism for delays in installing detectors. Some countries have resisted their installation, saying they may slow traffic at ports. The installation of the system in Yangshan, Shanghai's deepwater port, reflects “the commitment of the Chinese government to interdicting nuclear material and in combating nuclear terrorism,” said Thomas D'Agostino, who heads the National Nuclear Security Administration. Although Washington and Beijing have clashed over issues such as Iran's nuclear program, China won praise from US officials for its role in seeking to help defuse tensions over NKorea's nuclear activities.