For two days in May, ABC News had exclusive access as Bolshinsky and the U.S. team, along with Russian scientists and the International Atomic Energy Commission, painstakingly measured and recorded every ounce of fresh, weapons-grade, highly enriched uranium from the Latvia reactor.
"You can pick it up with your bare hands," Bolshinsky said. "I use gloves just to protect my hands, but yeah, it can be handled with just your bare hands. That's why it's so attractive to terrorists and other bad guys."
Each fuel rod was carefully wrapped in paper and cloth, labeled, then placed into two specially built metal casks supplied by Russia.
"After we remove this material, this country going be free of fresh HEU," Bolshinsky said, using the acronym for highly enriched uranium. "So we, we cleanse the country. We remove all fresh HEU which was stored here."
Ultimately, only about 6.5 pounds -- a fraction of what is needed to build a nuclear bomb -- was removed from Latvia. At a cost of $340,000 for the operation, that's about $51,500 a pound. In the next five years, the United States expects to spend more than $500 million to reduce the nuclear threat worldwide, including in the former Soviet Union.
But critics say that's nowhere near enough, and that hundreds of millions more are needed. Brooks disagrees.
"Our problems are not primarily money," he said. "Our problems are access in the Russian Federation. Our problems are convincing other countries that they need to take the threat as seriously as we are, and we keep working through that. The greatest incentive in the world is to understand that we're all in the cross hairs, and therefore we want to take away the bullets."
Brooks added that the process will not be quick, despite the urgency that is noted by critics. "It's a cooperative effort," he said. "It involves other countries. And so, if they think other countries should have greater urgency, don't tell me, tell them. And secondly, some of this just simply takes time."
But critics say we don't have time and point to 18 confirmed incidents of nuclear smuggling in the last decade.
Nuclear physicist Peter Zimmerman said not enough is being done to protect America. "All of our recovery efforts are fragmented," he said. "They're under-funded. The United States can afford to spend the money to recover this material ... a lot more than it can afford to replace a city."
He stressed that the threat is serious. "You seen the pictures of Hiroshima and Nagasaki lately?" Zimmerman said. "It's that serious."
It is in part the fear of failure that keeps Bolshinsky going. Before he left Latvia, he went to a former Nazi concentration camp not far from the reactor. Tens of thousands of Jews were murdered there during World War II, including 7,000 children.
"When we trying to prevent proliferation of nuclear weapons, we actually trying to prevent another nuclear war," he said. "And you see how many people was killed, how many people died, during the Second World War. And you realize that the third World War can be much bigger than that. Much more people will die. And it's what keeps you running."
ABC News' Cynthia McFadden reported this story for Nightline.