High Resolving Power, Broadband Spectroscopy for Nuclear Materials Control

The monitoring of spent nuclear fuel is not only critical to the operational safety of power plants, but also for nuclear materials control and accountability. Furthermore, up to 30% of energy may be recovered from reprocessed spent nuclear fuel, reducing high level radioactive waste. While radiation sensors may provide measurements of radioactivity, they often lack material selectivity to fully characterize nuclear fuels. New non-radiation sensors are needed, and specifically, sensors that can provide accurate elemental composition of the nuclear materials in a safe manner. Our proposed technology uses a high resolution, broadband spectrograph for laser-induced breakdown spectroscopy to detect small isotopic shifts in the emission lines of nuclear materials. Characterizing the isotopic shifts allows the content of the nuclear material to be measured without any sample preparation. Measurements can be carried out remotely, reducing any nuclear radiation risks to personnel. Our proposed instrument will measure small isotopic shifts across a broad spectrum, allowing the detection of isotopic shifts where they do not have interferences from the complex spectra associated with radioactive elements. In Phase I, we have demonstrated – through optical modeling – the capability of our broadband, high resolution spectrometer to characterize spent nuclear fuels. In Phase II, we will develop the hardware for the construction of the proposed spectrograph to achieve a resolving power of over 200,000 for isotopic analysis of nuclear materials. We will verify the spectrograph’s capabilities using stable isotopes before testing it with spent nuclear fuels at a national research laboratory. In addition to monitoring spent nuclear fuel, this technology may also be used for national security concerning nuclear safeguards and non-proliferation due to the high resolving power and broad spectral bandwidth of the new instrument. Commercial applications include geological exploration and mining, materials processing, laser spectroscopy, forensics/provenance, and biomedical and pharmaceutical analyses, such as drug testing. Our high-resolution detector will be capable of capturing optical signatures of nuclear materials. The proposed technology provides a safe technique to accurately measure and monitor spent nuclear fuel in nuclear power plants, and can also be used for nuclear safeguards and non-proliferation.