Technical Nuclear Forensics

Investigating Nuclear Samples

Following the dissolution of the Soviet Union in 1991, the fear of a nuclear exchange between the U.S. and the Soviets was largely reduced. However, concerns grew over the nuclear ambitions of subnational terrorist groups and rogue states. U.S. officials worried that such groups could acquire special nuclear material (SNM) or other radiological substances and use them in either an improvised nuclear device (IND) or a radiological dispersal device (RDD).

Fortunately, neither scenario has occurred, although weapons-usable uranium and plutonium have been seized on the black market during illicit trafficking attempts.

Keeping the Nation Secure

The science of analyzing seized materials plays a critical role in keeping the nation secure by providing essential information regarding the origin, process history and suspected use of the nuclear material. Nuclear forensic analysis involves the measurement of the physical, chemical, elemental and isotopic properties of nuclear material to answer questions from law enforcement and nuclear security organizations. Employed alongside conventional forensic science (e.g., fingerprints, DNA, crime scene analysis, etc.), nuclear forensics can be used to discover gaps in the nuclear material security regime and can deter the illicit trafficking of nuclear material by state or non-state actors.

LLNL has been a leader in nuclear forensic science since the early 1990s. In addition to pre-detonation forensics, which focuses on nuclear or other radioactive materials of both known and unknown origin, we also prepare for the analysis of materials used in an IND or RDD explosion, were one to occur (post-detonation nuclear forensics). Our multidisciplinary nuclear forensic team is responsible for generating reliable, high-quality analytical results that are legally defensible in a court of law, and that can be used to reveal the origin and history of nuclear materials.

Pre-Detonation Materials

Our expertise in nuclear materials has enabled LLNL to become the premier laboratory for nuclear forensic analysis of SNM. Our scientists support local, state, federal and international partners by delivering highly accurate measurements of nuclear materials with both unknown or known provenance.

These measurements can be used to assess the intended use of the material, the date and method of production, the enrichment technology used and even steps in the reprocessing of nuclear fuel. Many of these techniques can be utilized even with very small samples, which may be all that is available in an illicit trafficking investigation.

We also support the analysis of representative nuclear samples that are maintained in the national archive.

Investigation Support

When nuclear and radiological materials are encountered out of regulatory control, the incident must be investigated to determine several factors:

Where the material came from
Where and when legitimate control was lost
Who may have been involved
Whether additional material may be missing
What the appropriate law enforcement or national security response should be

LLNL supports the federal government in analyzing forensic evidence and providing a technical assessment of the incident. For interdicted threat devices, we prepare field-deployable teams with specialized equipment and expertise in weapons engineering, explosives handling, arming and firing, detonators, device design and other specialties.

Post-Detonation Materials and Device Assessment

LLNL specialists maintain readiness to collect detonation debris in the event of an unattributed nuclear detonation on U.S. soil, process evidence in the field and deliver high-quality samples to the Federal Bureau of Investigation in the event of a successful attack using radiological or nuclear materials on U.S. soil or partner countries. Our nuclear weapons expertise is also used in performing assessments of the design and materials associated with the detonated device. To assure readiness for such a scenario, LLNL performs R&D to improve measurement techniques and to decrease timelines in delivering an actionable response following collections. LLNL also supports the assessment of national post-detonation analytical capabilities through production of high-fidelity surrogate debris materials.

Nuclear Threat Reduction