The CNSC laboratory: An innovator in nuclear forensics

Since 1999, the Nuclear Forensics International Technical Working Group (ITWG) has organized collaborative material exercises (CMXs) in an effort to advance best practices and improve international understanding of nuclear forensic analysis and interpretation. Nuclear forensics is the scientific analysis of nuclear or other radioactive materials, or evidence contaminated with radioactive materials, which contributes to the broader investigation of a nuclear security event. In the unlikely event that radioactive materials are found out of regulatory control, nuclear forensic science can provide insight into their history and origins.

In 2016, the CNSC laboratory staff represented Canada in the CMX-5 and put their skills to the test, working in this exercise with other nuclear forensic analysis practitioners. The fictitious CMX-5 exercise had elements reminiscent of a riveting episode of crime drama! In this exercise scenario, law enforcement intercepted two nuclear fuel pellets smuggled by a pair of courier driver brothers. The participants, comprising 20 laboratories from around the world, were tasked with analyzing the materials to find clues for law enforcement in order to identify and build a criminal case against the perpetrators.

The CNSC laboratory staff decided to take a unique approach to this challenge. They used laser ablation coupled to an inductively coupled plasma mass spectrometer (LA-ICP-MS) to study the surfaces of the fuel pellets. This allowed them to determine their isotopic homogeneity and purification date. The results of these analyses provided important clues on processes and materials used to manufacture the pellets, which, paired with other results and information, enabled identification of the manufacturing facility.

The LA-ICP-MS equipment housed at the CNSC laboratory

The CNSC was the only lab to use LA-ICP-MS, which provided results consistent with much more expensive and specialized techniques. The CNSC’s laboratory staff presented their LA-ICP-MS work at the CMX’s data review meeting in April 2017 and at the 22nd annual ITWG meeting in June 2017. Their work was very well received, and the CNSC was subsequently asked to write a technical guideline on the use of LA-ICP-MS in nuclear forensic analysis. Moreover, the CNSC has been tasked to lead the publication of a journal article that will compare LA-ICP-MS with other techniques used in the spatial analysis of fuel pellets in CMX-5.

The CNSC laboratory has studied the LA-ICP-MS technique extensively as part of two Canadian Safety and Security Program projects: the Nuclear Material Signature & Provenance Assessment Capability Development Project and the National Nuclear Forensics Capability Advancement Project. These studies led to a new analysis method using LA-ICP-MS, applicable for "fingerprinting" nuclear materials from the uranium fuel cycle, such as yellowcake and fuel grade uranium oxides. The CNSC laboratory now also uses LA-ICP-MS to determine purification dates of uranium fuel pellets, which helps to identify their manufacturing facility.

The CNSC is proud of this development and continues to strive for innovative ways to share our best practices on the national and international stage.