Nuclear power is enjoying rapid growth as government energy policies and public demand shift toward low-carbon energy production. Pivotal to the global nuclear power renaissance is the development and deployment of robust safeguards instrumentation and new environmental sample collection and analysis methods for the detection of highly enriched uranium (HEU). Undeclared production of HEU remains a primary proliferation concern for modern enrichment plants. 

Environmental sample collection and ultrasensitive laboratory analysis has proven to be an effective deterrent to undeclared enriched uranium production within a gaseous centrifuge enrichment plant (GCEP). Current GCEP misuse monitoring has a very long timescale—often months—between environmental sample collection and reported laboratory analysis results. Researchers at Pacific Northwest National Laboratory are developing an unattended safeguards instrument, combining continuous aerosol particle collection with uranium isotope assay, to reduce the cost and timescale of GCEP misuse monitoring.

PNNL’s Laser Ablation, Absorbance Ratio Spectrometry-Environmental Sampling (LAARS-ES) method, is based on laser vaporization of aerosol particles, followed by laser spectroscopy to characterize the uranium enrichment level. LAARS aerosol collectors are contained within tamper-indicating enclosures and deployed near feed and withdraw station locations and elsewhere to continuously collect aerosol samples. This on-site safeguards approach features a pre-determined aerosol particle collection interval and time-stamped sampling for traceability back to facility declarations. The collector is removed during onsite inspections and inserted into the LAARS-ES instrument to conduct onsite uranium particulate sample assay. With this new method, the entire aerosol collector surface can be quickly scanned at high spatial resolution, collecting, evaluating, and interpreting millions of enrichment measurements per hour, providing on-site enrichment analysis that significantly improves the timeliness of enrichment facility misuse detection.