Experts warn that a lack of specialists in the field of nuclear forensics may make it difficult in the future to trace the origin of dirty bombs.
In a world of rogue nuclear powers, a black market in atomic materials, and large-scale global terrorism, the ability to determine the sources of illicit nuclear materials and—in the event of an attack—to assign responsibility, is critical. But experts warn that U.S. nuclear forensic capabilities are not what they should be, and their sustainability into the future is at risk.
Nuclear materials, whether they are interdicted before they have been used in a weapon or collected after the detonation of a nuclear weapon or radiological dispersal device (a “dirty” bomb), do not bear straightforward “fingerprints” linking them to specific facilities or states. Different traits, however, can lead investigators to the source. Materials’ properties can indicate, for example, where the base elements were mined and what type of reactor they were manufactured in.
The chemical characteristics of debris from a detonation can lshow what fuels were used, the type of device, and its quality. Those factors can help determine the sources of devices or materials and, just as important, rule others out.
The science of nuclear forensics dates to the early years of the nuclear age. The Soviet Union’s first detonation of a nuclear bomb, for example, was detected through analysis of airborne debris captured by a U.S. military reconnaissance plane. And throughout the United States’ nuclear testing program, scientists studied materials left in the aftermath of detonations to assess devices’ effectiveness.
The U.S. nuclear testing program, however, ended in 1992. In the years since, fewer and fewer students have pursued study in subjects central to nuclear forensics, like radiochemistry. At the same time, more and more graduates have taken work in the private sector as opposed to working in research institutions like the Department of Energy’s (DOE) national laboratories.
Leaders in nuclear science and nonproliferation first sounded the alarm in a 2008 report by the Joint Working Group of the American Physical Society (APS) and the American Association for the Advancement of Science (AAAS). The authors reported then that only about 30 to 50 scientists worked in nuclear forensics at national laboratories, and of them, one third to one half were expected to retire within the next 10 to 15 years. The authors urged establishment of government recruitment and scholarship programs to reconstitute their ranks.
The report’s findings were substantiated by the U.S. Government Accountability Office (GAO) and the National Research Council. The result has been some movement to address concerns. The Department of Defense (DoD) is developing a five-year plan to ensure coordination, staffing, and adequate funding between the disparate government agencies responsible for nuclear counterproliferation and forensics, among them the FBI, the DOE’s National Nuclear Security Administration, the DoD’s Defense Threat Reduction Agency, and the Department of Homeland Security’s (DHS) National Technical Nuclear Forensics Center (NTNFC).
More recently, President Barack Obama signed legislation into law charging NTNFC with overseeing implementation of the multi-agency five-year plan. The law further established the National Nuclear Forensics Expertise Development Program under which DHS must recruit new nuclear forensic scientists and fund scholarships for undergraduate study, doctoral fellowships, internships at the national labs, and research awards for faculty researchers.
Scholarship recipients will in turn be obligated to work for two years after graduation in a forensics post, either at a national lab or federal agency. DHS expects to see the program generate three to four Ph.Ds annually.
The APS/AAAS report also notes that even with an adequate number of specialists, forensic analysis can take weeks or months. Nuclear forensics would benefit from establishment of an international database of the world’s nuclear materials containing data about their characteristics, accompanied by samples. Separate, limited collections are kept by the United States, Russia, the International Atomic Energy Agency, and the European Commission’s Institute for Transuranium Elements in Germany.
Samples and data from rogue states like Iran and North Korea, however, are hard to come by and hard to trust. International inspectors testing a plutonium sample secured from North Korea discovered the country had mixed two separate types to “spoof” foreign databases. While forensic scientists detected the ruse, future attempts “may or may not mislead analysts,” according to the APS/AAAS report.
Improving portable, rugged, and analytic technology can relieve some of the demand for human expertise. For example, Lawrence Livermore National Laboratory has developed technology that can test the chemical components in nuclear material without separating them. And its Pacific Northwest National Laboratory has introduced automation into analytic processes, while accelerating them, according to the GAO. But technology can by no means replace the need for human expertise entirely, practitioners caution.