U.S. Lab Develops Off-Gas Monitoring Tools

Researchers at the Pacific Northwest National Laboratories announced this week the development of a real-time off-gas monitoring system designed for nuclear plant operators that can inform them faster about when to task items like treating or scrubbing such by-products as iodine gas.

PNNL Chemist Amanda LinesSensing it is time for a faster monitoring system, given the push for next-generation nuclear technology, PNNL researchers said the process “combines remote, real-time testing and continuous monitoring of off-gas by-products … coupled with a software package geared towards plant operators.”

The new tool can speed up development of reactors, given the time current off-gas sample collections and lab analysis can take.

In liquid-fuel molten salt reactors the monitoring system today “is both slow and expensive – not to mention [dangerous],” PNNL said. However, real-time monitoring can lead to real-time scrubbing, a distinct advantage over the test and see approach used today. Complicating matters further, off-gas iodine has a tendency to morph, “creating new molecules with different properties,” PNNL noted. Monitoring a fast-morphing byproduct “would be like baking a spice cake and then asking someone to figure out each ingredient,” the lab said.

To make the complexities manageable, the research team focused its sights on targeting two common forms of iodine—iodine monochloride and elemental iodine—and dialing in methods to quantify each. The goal was to search for the chemical “fingerprints” for each type of iodine produced using two common chemical analysis techniques—Raman spectroscopy and Fourier-transform infrared spectroscopy, PNNL said.

After that, it was up to the software team to sort it all out. “We want an output that is easily understandable, especially for someone who hasn’t spent years of their life staring at spectrometry data,” said PNNL Chemist Amanda Lines.

Anonymous comments will be moderated. Join for free and post now!