Nukes of hazard

WASHINGTON-The largest gathering of world leaders in Washington since 1945-47 of them altogether-locked up streets downtown and sent motorcades regularly zooming through city blocks. Washingtonians who live in the blocks within the downtown security perimeter of the Nuclear Security Summit had to show identification every time they entered and exited their homes while security searched their belongings. One of the city's central metro stops near the summit was closed, and federal workers were encouraged to work from home.

On Monday the Obama administration celebrated two announcements that indicate the buzz surrounding the summit isn't purely ceremonial. First, Ukraine agreed to dispense with its weapons-grade uranium, which is enough to build several nuclear weapons. The United States has been urging the former Soviet bloc country to abandon its highly enriched uranium for about a decade.

Ukraine had developed its nuclear program at a high cost: The 1986 nuclear meltdown in Chernobyl was the worst nuclear accident in history, inflicting heavy radiation on the nearby city of 50,000 and sending contaminated clouds over countries as far away as Poland and Germany. The meltdown released 400 times more radioactivity than what was released at Hiroshima, according to National Geographic. The surviving Chernobyl population is still paying the price for the heightened levels of radiation in higher rates of cancer.

The question remains where Ukraine will send its uranium for disposal. White House spokesman Robert Gibbs hinted that the United States would help take care of it.

"I think the American people feel wholly more confident that the material of which not a huge amount can destroy an entire city, I think they'd feel far more secure knowing that that material is under safe lock and key and guarded in this country, rather than potentially floating around somewhere else," he said Monday. "Some of it may be here, some of it may not be here."

The fear is that international caches of highly enriched uranium even in friendly countries could be leaked to countries with more sinister designs, like Iran. And Iran is the pressing concern, even if the summit hasn't been billed that way. The United States has been lobbying China, a UN Security Council member with veto power, to support sanctions against the country. On Monday President Obama met for an hour-and-a-half with Chinese President Hu Jintao.

After the meeting, Jeff Bader from the National Security Council announced that China was willing to work with the United States on a UN sanctions resolution against Iran, a major step in negotiations. The White House expects a resolution to move forward in a matter of weeks, though Chinese diplomats have sounded more cautious tones. China has supported three watered-down sanction resolutions against Iran in the past, but its support is capricious because it relies on Iran for about 12 percent of its oil.

Several leaders of the United States' closest allies did not attend the summit. British Prime Minister Gordon Brown was absent as he finds himself in the middle of a campaign for the country's May 6 elections. Israeli Prime Minister Benjamin Netanyahu initially planned to come to the summit but pulled out at the last minute over concerns that other Arab nations would censure the nation's very private nuclear program. Some Arab officials suggested that Netanyahu wanted to avoid another confrontation with President Obama over Jewish settlements, but Israeli leaders have avoided past meetings on nuclear weapons because of a desire to keep the country's program as hushed as possible.

Iran and North Korea, both under global scrutiny for their nuclear programs, were not invited.