The security of nuclear material has long been an issue of concern in Russia and other former Soviet republics. For 10 years the United States has funded a program dealing with the problem, and experts say progress is being made. Nonetheless the potential proliferation of some kinds of "loose nukes" remains a serious concern.
Earlier this year a man was arrested in central Russia after police found several canisters in his backyard that contained nuclear waste.
The man said he found the canisters at a local dump and decided to move them to his yard "for safekeeping." The case is still under investigation.
This was one recent example of what some call "loose nukes," material which is unlikely to be suitable in making a nuclear bomb. However if packed together with conventional explosives, it could be used in a so-called "dirty bomb" with potentially serious consequences.
Preventing such material from falling into the hands of terrorist groups or rogue states has been a concern since the end of the Cold War.
And much of the focus for this has been on Russia and other former Soviet republics, which have many nuclear installations ranging from power plants to laboratories.
In the northwestern Murmansk region near the border with Norway, dozens of Soviet-era nuclear submarines sit in a bay waiting to be dismantled.
An old ship serves as a waste dump, posing not just a nuclear threat but an environmental one as well.
Military officials themselves say that tons of nuclear material sit out in the open, and have called for more funding to deal with the problem.
While most installations have security guards and surveillance cameras, experts say this is no guarantee that radioactive material is secure.
Yevgeny Volk, an analyst with the Heritage Foundation in Moscow, says that low salaries and low morale in the Russian military add to the problem.
"Due to the increased level of corruption, the increased level of mismanagement and fraud in the armed forces and in general in defense-related industries, the risk of nuclear proliferation is surely high," he said.
Mr. Volk adds the threat is not limited to nuclear materials, but also to the scientists, bomb experts and others with nuclear know-how.
He says many Russian nuclear experts have gone abroad to places like Iran, where a Russian nuclear power plant has been under construction for many years.
Both Iran and Russia insist the project is exclusively for peaceful purposes.
But others are not so sure, and the issue has been a sore point in relations between Moscow and the United States for the past decade.
However cooperation with Russia has provided a genuine success story concerning "fissile" nuclear material, which is used to make bombs.
In 1993 Russia and the United States started the "Megatons to Megawatts" program to convert highly-enriched uranium from Soviet nuclear warheads into low-grade nuclear fuel for use in American power plants.
So far 225 metric tons of material, enough to make 9000 nuclear warheads, has been turned into fuel; the goal is to reach 500 tons within the next decade.
Charles Yurlish is a senior official with the global energy company USEC, which is carrying out the program.
He says nuclear material from what were once Soviet warheads now provides 10 percent of all electric power in the United States.
"There's an exquisite symmetry to the fact that Soviet missiles with nuclear warheads that were once aimed at American cities are now providing light and power to those very same cities," he said.
Mr. Yurlish adds that the "Megatons to Megawatts" program is the largest nuclear disarmament program in history, and can serve as a model for other programs in some of the world's other nuclear powers.