Machine learning-assisted laser-induced breakdown spectroscopy for monitoring molten salt compositions of small modular reactor fuel under varying laser focus positions

Lee, Yunu; Foster, Richard I.; Kim, Hyeongbin; Choi, Sungyeol

doi:10.1016/j.aca.2023.340804

Cited by 8 publications

(16 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…325 Relatively few studies have attempted to measure salts in their molten state. 298,[326][327][328][329] Hanson et al 327 investigated the response of the LIBS signal to the temperature of the salt sample. The temperature was varied such that the sample was tested as a solid salt, in a transition state, and ultimately, in molten form.…”

Section: Online Monitoring and Pyroprocessingmentioning

confidence: 99%

“…They were able to monitor Sr and Mo in LiCl-KCl at concentrations ranging from 500 to 7000 ppm using a machine learning algorithm trained on purposefully defocused LIBS spectra to account for fluctuations in salt surface level height variations. 328 Lastly, an aerosol system was developed by Williams and Phongikaroon 330,100 for online monitoring of pyroprocessing salts. The aerosol system used a Collison nebulizer to mitigate clogging issues due to the presence of a high concentration of salts, where LIBS was performed directly on the aerosol stream.…”

Section: Online Monitoring and Pyroprocessingmentioning

confidence: 99%

“…Multiple separate PLS models have been developed to perform in situ online monitoring of elemental concentrations in molten salts, and aim to determine either the uranium content in the salt during the reprocessing of spent nuclear fuel 297,330 or the amount of fission products (Sr and Mo) in the salt during reactor operations. 328 Additional applications of regression algorithms in the nuclear LIBS community involve the development of multivariate spectral fitting algorithms to determine the isotopic composition of uranium. Current models require the manual selection of emission lines and are limited to narrow wavelength windows (<1 nm).…”

Section: Machine Learning As An Analysis Approach To Libs Measurementsmentioning

confidence: 99%

See 2 more Smart Citations

Laser Ablation Plasmas and Spectroscopy for Nuclear Applications

Kwapis,

Borrero,

Latty

et al. 2023

Appl Spectrosc

View full text Add to dashboard Cite

The development of measurement methodologies to detect and monitor nuclear-relevant materials remains a consistent and significant interest across the nuclear energy, nonproliferation, safeguards, and forensics communities. Optical spectroscopy of laser-produced plasmas is becoming an increasingly popular diagnostic technique to measure radiological and nuclear materials in the field without sample preparation, where current capabilities encompass the standoff, isotopically resolved and phase-identifiable (e.g., UO and UO[Formula: see text]) detection of elements across the periodic table. These methods rely on the process of laser ablation (LA), where a high-powered pulsed laser is used to excite a sample (solid, liquid, or gas) into a luminous microplasma that rapidly undergoes de-excitation through the emission of electromagnetic radiation, which serves as a spectroscopic fingerprint for that sample. This review focuses on LA plasmas and spectroscopy for nuclear applications, covering topics from the wide-area environmental sampling and atmospheric sensing of radionuclides to recent implementations of multivariate machine learning methods that work to enable the real-time analysis of spectrochemical measurements with an emphasis on fundamental research and development activities over the past two decades. Background on the physical breakdown mechanisms and interactions of matter with nanosecond and ultrafast laser pulses that lead to the generation of laser-produced microplasmas is provided, followed by a description of the transient spatiotemporal plasma conditions that control the behavior of spectroscopic signatures recorded by analytical methods in atomic and molecular spectroscopy. High-temperature chemical and thermodynamic processes governing reactive LA plasmas are also examined alongside investigations into the condensation pathways of the plasma, which are believed to serve as chemical surrogates for fallout particles formed in nuclear fireballs. Laser-supported absorption waves and laser-induced shockwaves that accompany LA plasmas are also discussed, which could provide insights into atmospheric ionization phenomena from strong shocks following nuclear detonations. Furthermore, the standoff detection of trace radioactive aerosols and fission gases is reviewed in the context of monitoring atmospheric radiation plumes and off-gas streams of molten salt reactors. Finally, concluding remarks will present future outlooks on the role of LA plasma spectroscopy in the nuclear community.

show abstract

Section: Online Monitoring and Pyroprocessingmentioning

confidence: 99%

Section: Online Monitoring and Pyroprocessingmentioning

confidence: 99%

Section: Machine Learning As An Analysis Approach To Libs Measurementsmentioning

confidence: 99%

See 1 more Smart Citation

Laser Ablation Plasmas and Spectroscopy for Nuclear Applications

Kwapis,

Borrero,

Latty

et al. 2023

Appl Spectrosc

View full text Add to dashboard Cite

show abstract

“…In MSR-related research, LIBS has been used for the analysis of solid samples, [15][16][17][19][20][21][22]24,33 actual molten salts in the liquid state through surface sampling, 14,[25][26][27] aerosols produced from surrogate salts and/or analytes, 18,28,30,34 aerosolized particles from actual molten salts, 32,36 and off-gassed products from actual molten salts. 17,29 The analysis of solid surfaces, typically as compressed pellets or after melting and solidification, has been performed to identify analyte emission lines and evaluation of LIBS performance.…”

Section: Introductionmentioning

confidence: 99%

“…Laser-induced breakdown spectroscopy (LIBS) 10–12 is an atomic emission spectroscopy technique that has been proposed for application and used for off-line and online analysis of several types of nuclear- and MSR-related analytes, molten salt surrogates, and actual molten salts in solid, liquid, and aerosol states. 8,9,13–36 In LIBS, a laser beam is used to simultaneously sample, atomize, and excite the target material, and create a unique chemical fingerprint (i.e., LIBS spectrum). The use of LIBS for online monitoring of MSR environments arises from its capability of analyzing any type of sample (e.g., solid, liquid, gas, or aerosol) in situ, noninvasively, and without sample preparation; only optical access to the target is required.…”

Section: Introductionmentioning

confidence: 99%

Detection of Off-Gassed Products From Molten Salts Using Laser-Induced Breakdown Spectroscopy

Díaz

Hahn

2023

Appl Spectrosc

View full text Add to dashboard Cite

The detection of off-gassed sodium from molten sodium nitrate (NaNO3) at temperatures between 330 °C and 505 °C and off-gassed calcium from molten lithium chloride–potassium chloride eutectic (LKE) mixtures at 510 °C with laser-induced breakdown spectroscopy (LIBS) was demonstrated. NaNO3 and LKE samples were melted in a custom-built crucible that promoted the generation of off-gassed products from the molten sample. The off-gassed products were analyzed with a LIBS system designed to probe the high-temperature environment. Na D emission lines, Na(I)588.99 nm and Na(I) 589.59 nm, were detected from the NaNO3 samples after reaching a temperature threshold, which indicated the occurrence of phase change. In LKE mixtures, the detection of Ca impurities at a concentration of 78 mg/kg was possible using the emission lines Ca(II) 393.66 nm and Ca(II) 395.85 nm. This work demonstrates the real-time monitoring capabilities of LIBS in high-temperature environments that simulate the conditions of molten salt reactors.

show abstract