Molten salt reactors (MSRs) are a subset of Generation IV nuclear reactors which use molten salts (chloride salts, fluoride salts, etc.) as the coolant as well as the fuel mixture. MSRs feature homogenous fuel composition, lower operating pressure with higher operating temperatures than traditional nuclear reactors and can perform online refueling. During operation, MSRs produce off-gases that are vented from the reactor core and need to be treated in follow-on processes. One proposed treatment step of the process involves a molten hydroxide eutectic scrubber which scrubs iodine species. The composition of the scrubbing medium and speciation of the off-gas entering and exiting the scrubber are crucial pieces of information for the operation of the scrubber, as well as the ingrowth of process and environmental interferents. Online monitoring using optical spectroscopy can be used to provide this critical information in a way that operators can use in real time to make process adjustments. Raman and UV-Vis spectroscopy are excellent candidate techniques as they both provide composition and speciation information about the molten eutectic as well as the gas phase. Here, we show the use of a dual-liquid/gas phase Raman measurements to obtain iodate fingerprints in the molten NaOH-KOH eutectic as well as follow interferent carbonate species from the gas phase (CO<sub>2</sub> to the molten phase).

Iodine and carbonate species monitoring in molten NaOH-KOH eutectic scrubber via dual-phase <i>in situ</i> Raman spectroscopy

Fall 2022 abstracts, posters, and presentations will launch in mid-September.

ACS Fall 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Iodine and carbonate species monitoring in molten NaOH-KOH eutectic scrubber via dual-phase in situ Raman spectroscopy