Scientists and experts in nuclear detection gathered near Richland during the past two weeks to learn the latest methodologies in the fledgling field of nuclear forensics. That is the science of studying nuclear material to trace it to its source or gather other information in a criminal investigation.
The need for the first-of-a-kind training is more than theoretical.
The International Atomic Energy Agency, or IAEA, has confirmed 399 cases of smuggled, stolen and other criminal possession of nuclear materials since 1993. That includes 16 incidents involving weapons-usable enriched uranium or plutonium.
With the use of nuclear forensics, information can be developed to prosecute cases and also to discover the vulnerabilities in security that allowed material to fall into criminal hands.
Developing the field of nuclear forensics also can serve as a deterrent, discouraging criminal activity as it becomes known that seized nuclear material can be traced back to a place or a person, said David Smith, IAEA senior nuclear security officer.
The IAEA's Office of Nuclear Security organized the conference with Pacific Northwest National Laboratory in Richland and the National Nuclear Security Administration, with classes at the HAMMER training center at Hanford and demonstrations of sophisticated scientific instruments at PNNL.
The 24 participants in the conference built on their technical and scientific backgrounds to develop their skills to conduct a comprehensive nuclear forensics investigation in cooperation with law enforcement, Smith said. Argentina, Brazil, China, Georgia, Hungary, Japan, Russia, South Africa, South Korea, Spain, Turkey and Uzbekistan were represented.
"With the growth in nuclear energy, including in Asia ... there is a need to do it safely," Smith said. "It's in the state's interest to have nuclear forensics."
Scientists at PNNL and elsewhere recognized in the mid-'90s the potential value of nuclear forensics and how it could be applied. They built on knowledge developed at the Hanford nuclear reservation and other nuclear weapons sites through the Cold War about the nuclear production process that could be applied to law enforcement, Smith said.
"It's a new field built on 50 years experience," Smith said.
Each point in the nuclear fuel cycle that introduces a process that affects a change also introduces a "fingerprint" on the nuclear material, said Jon Schwantes, a PNNL senior scientist.
It can be physical, such as a tool mark or the different sizes and shapes of fuel pellets manufactured for nuclear reactors.
Or the tell-tale signs can be chemical, starting with differences that show where the ore that produced the nuclear material was mined, Schwantes said. The chemical signature of the radiological material also can allow it to be traced back to a specific type of reactor.
Schwantes, for instance, was able to determine in 2008 that plutonium in a safe unearthed during cleanup of a Hanford burial ground was the world's second oldest known man-made plutonium 239. It had the unique chemical fingerprint of the small X-10 reactor in Oak Ridge, Tenn., a 1940s prototype for Hanford's B Reactor, the world's first full-scale nuclear reactor.
It is that sort of research that has given the international community confidence in the ability of nuclear forensics to play a role in criminal investigations, Smith said.
As a result of information available from PNNL and other sources, questions about seized material may be answered. That includes where it came from, if there is more of it, if the material is a type that is a threat and if additional material is vulnerable to criminal activity, Smith said.
The workshop shared new developments and technical guidance needed to conduct a comprehensive nuclear forensic investigation, he said.
"The idea is that with common approaches and understanding, it is easier to compare data and come to a conclusion," Smith said.
At the HAMMER training center, international visitors received hands-on training, with demonstrations conducted with reactor-grade material, weapons-grade plutonium and enriched uranium.
They practiced searching for illicit materials, then identifying and collecting evidence while containing radioactive contamination and maintaining a chain of custody. They also practiced working with law enforcement to develop an analytical plan to serve law enforcement needs.
At PNNL, they watched demonstrations of radio-chemical separations and toured advanced microscopy labs where a variety of optical and scanning and transmission electron microscopes are used to probe radioactive materials at extremely small scales.
At the most basic level, every country needs the capability to determine whether nuclear materials are usable for weapons, Schwantes said. Then regional and international collaborations can be used to provide more advanced analysis.
Workshop speakers and instructors included experts from the FBI, the Australian Nuclear Science and Technology Organization, the European Commission Joint Research Center's Institute for Transuranium Elements, the United Kingdom's Atomic Weapons Establishment, the IAEA, NNSA and PNNL and other national labs.