More advanced technology helps ensure the peaceful use of nuclear materials

The tool allows for quick, accurate analysis of nuclear materials at virtually any nuclear facility

March 31, 2022

Eric Feissle of NPI-9 placing a nuclear material item for measurement with SOFIA.

Providing faster, more accurate and more cost-effective analysis of nuclear materials such as uranium and plutonium is important for helping to better safeguard against their misuse. Los Alamos National Laboratory developed a tool called SOFIA (Spectrometer Optimized for Facility Integrated Applications) to do just this by capitalizing on key advances in ultra-high-resolution microcalorimeter technology. Its reduced infrastructure requirements and high analysis precision make it optimal for operation in any nuclear facility or analytical laboratory.

SOFIA is essentially a better, high-resolution “camera” to determine the isotopic composition of nuclear materials, which is critical for ensuring the peaceful use of these materials.

“Nuclear technologies, such as carbon-free nuclear power generation and nuclear medicine, are an essential part of modern life and used widely around the world,” said Mark Croce, SOFIA’s principal investigator. “Correspondingly, the nuclear material used in these technologies must be continually verified to ensure that it is not diverted to nuclear weapon pathways. Instruments are needed that more rapidly and accurately assess the composition of nuclear materials. SOFIA can do this because of its exceptionally high-energy resolution.”

SOFIA provides approximately 10 times better resolution than standard high-purity germanium detectors in a relatively small instrument. The smaller size means that it can be operated in nearly any facility, such as nuclear fuel-cycle facilities, medical-isotope production facilities, environmental monitoring laboratories and other locations that require analysis of nuclear and radioactive materials to verify that they are being used for peaceful purposes and not diverted to fabricate nuclear weapons.

The need for improved instruments such as these is great. The International Atomic Energy Agency is responsible for verifying nuclear material at more than 1,300 facilities around the world that, that if misused, could aid in the construction of more than 200,000 nuclear weapons. SOFIA provides a path to complete nondestructive analysis—which means the container holding the material does not need to even be opened—with precision and accuracy approaching what is possible in more costly sampling and destructive laboratory analysis.

Conventional gamma-ray spectroscopy is widely used to determine the isotopic composition of special nuclear materials such uranium and plutonium. However, with 1% to 3% uncertainty, the precision of conventional methods is insufficient to meet today’s increasing nuclear safeguards goals and responsibilities. The bulk of the analyses must be performed on samples that are collected and sent to analytical laboratories for destructive analysis, which is costly and time consuming.  Rapid, cost-effective, and nondestructive tools, such as SOFIA, could alleviate this situation. Furthermore, availability of improved, practical safeguards tools would boost adoption of safer and more economical advanced nuclear reactors.

LA-UR-22-23048, version 3