A new report says the world still faces a serious risk that terrorists could obtain a nuclear bomb and urges President-elect Barack Obama to make reducing that risk a top priority of U.S. security policy and diplomacy.  VOA correspondent Meredith Buel has details from Washington.

The new report, called "Securing the Bomb 2008," says major progress has been made to reduce the danger of nuclear terrorism.

The report warns, however, there are still major gaps in these efforts and says the risk of terrorists acquiring a nuclear weapon remains unacceptably high.

The author of the report, Harvard professor Matthew Bunn, says the potential for a disastrous attack is very real.

"That would incinerate the heart of a major city," he said.  "It could turn the center of Washington, D.C. or the center of Manhattan into a smoking, radioactive ruin that would be unusable for decades to come.  That would have profound and catastrophic affects on our society, really reverberating around the world."

The study is the seventh annual report from Harvard University's Belfer Center for Science and International Affairs and was commissioned by the Nuclear Threat Initiative, a nonproliferation group based in Washington, D.C.  

The report details a series of events around the world in recent years it says highlights the risk of poor security at nuclear installations.

These include an armed break-in at a South African site with hundreds of kilograms of highly enriched uranium, the arrest of a Russian colonel for soliciting bribes to overlook violations of nuclear security rules and the increasing terrorist threats amid the ongoing strife in Pakistan.

The report says the materials for a nuclear bomb exist in hundreds of buildings in dozens of countries.

Professor Bunn says there are currently about 130 research reactors around the world that still use highly enriched uranium for fuel.

"I think they are a quite serious concern because many of these facilities have very minimal security measures," he said. "Some of them are on university campuses and other locations where it is really not plausible that you would ever have the kind of security that in my view is required when you are talking about potential nuclear bomb material."

The report says there has been progress in the former Soviet Union in recent years.  It says U.S.-sponsored security upgrades have been completed for 75 percent of the buildings that contain weapons-grade material and for about 65 percent of Russia's nuclear warhead sites.  

The study says major issues remain, however, ranging from insider theft and corruption to chronic underinvestment in nuclear security.

The report also recommends expanding efforts to secure nuclear materials in China, India, Pakistan and South Africa.

The study contains an agenda for the next U.S. president to prevent nuclear terrorism and Professor Bunn says President-elect Barack Obama needs to accelerate efforts to combat the threat.

"They really need a comprehensive strategy to prevent nuclear terrorism, starting with locking down nuclear stockpiles all over the world, making sure that every nuclear weapon, every kilogram of plutonium or highly enriched uranium, wherever it may be, is secure and accounted for," he said.

Professor Bunn says the Obama administration should appoint a senior White House official, with direct access to the President, to supervise all efforts focused on preventing nuclear terrorism.