I guess that includes a "dirty bomb" - and there's no time-table, so yah, sure; 30% chance of a dirty bomb device in the next 100 years sounds feasible.

There's a free DVD movie dedicated to raising political awareness on the subject. "Last Best Chance" is an educational DVD that dramatizes the modern nuclear threat of international terrorist organizations, produced by the Nuclear Threat Initiative. The DVD is freely available through the NTI-supported website. The film stars Fred Thompson as President of the United States.: http://www.lastbestchance.org/

C-SPAN has aired a few intersting broadcasts on the subject that are available for online viewing:
On 07/18/2006 Undersecretary Joseph talked about the threat of nuclear terrorism - Topics included record of accomplishment, national strategy, network of partner nations, and transforming our diplomacy. He responded to questions from members of the audience: http://www.c-spanarchives.org/library/in...ighlight=threat

Joseph Cirincione is another good source who has been featured on CSPAN and has a few good books on the subject: http://video.google.com/videoplay?docid=-http://video.google.com/videoplay?docid=-3756009759863502593&q=Joseph+Cirincione+cspan&total=2&start=0&num=10&so=0&type=search&plindex=0

There are many other "experts" on WMD avialable by books/online video like Hans Blicks, Graham Allison, etc... the threats real but very difficult to assess by the average Humphrey Chimpden Earwicker...