Dr. Heather Felmy is a chemist focused on developing online monitoring tools for nuclear applications. She is involved in several projects designing and testing sensors used to measure target analytes in aqueous systems, gas phases, and molten salts for nuclear material processing applications.

Felmy’s work involves developing chemometric models, built from optical spectroscopy data, to allow for real-time monitoring of processes. These online monitoring capabilities can allow researchers, engineers, and operators to monitor systems in real time and make changes that allow for safe and effective operations. These tools are applicable to molten salt reactor technologies, used nuclear fuel recycling, and the cleanup of legacy waste.

Research Interest

  • Online monitoring
  • Optical spectroscopy
  • Electrochemistry
  • Spectroelectrochemistry
  • Chemometric analysis


  • PhD in Chemistry, Washington State University
  • BS in Chemistry, University of Washington

Affiliations and Professional Service

  • American Chemical Society, Member
  • Go Team Therapy, Crisis, and Airport Dogs, Member



  • Felmy, H.M., H.E. Lackey, A. Schafer Medina, M.J. Minette, S.A. Bryan, and A.M. Lines. 2022. “Leveraging multiple Raman excitation wavelength systems for process monitoring of nuclear waste streams.” ACS ES&T Water 2(3):465-473. PNNL-SA-166535. doi:10.1021/acsestwater.1c00408


  • Felmy, H.M., A.J. Clifford, A. Schafer Medina, R.M. Cox, J.M. Wilson, A.M. Lines, and S.A. Bryan. 2021. “On-Line Monitoring of Gas-Phase Molecular Iodine Using Raman and Fluorescence Spectroscopy Paired with Chemometric Analysis.” Environmental Science & Technology 55 (6):38983908. doi: 10.1021/acs.est.0c06137
  • Lackey, H.E., H.A. Colburn, M.V. Olarte, T. Lemmon, H.M. Felmy, S.A. Bryan, and A.M. Lines. 2021. “On-Line Raman Measurement of the Radiation-Enhanced Reaction of Cellobiose with Hydrogen Peroxide.” ACS omega. 6(51):35457–35466. doi: 10.1021/acsomega.1c04852
  • Andrews, H., J. Mcfarlane, S. Chapel, D.D. Bull Ezell, D.E. Holcomb, D. de Wet, M.S. Greenwood, K.G. Myhre, S.A. Bryan, A. Lines, B.J. Riley, H.M. Felmy, and P.W. Humrickhouse. 2021. "Review of Molten Salt Reactor Off-Gas Management Considerations." Nuclear Engineering and Design 385(December 2021):111529. doi:10.1016/j.nucengdes.2021.111529


  • Nelson, G.L., H.E. Lackey, J.M. Bello, H.M. Felmy, H.B. Bryan, F. Lamadie, S.A. Bryan, and A.M. Lines. 2020. “Enabling Microscale Processing: Combined Raman and Absorbance Spectroscopy for Microfluidic On-Line Monitoring.” Analytical Chemistry, 93(3):1643-1651. doi: 10.1021/acs.analchem.0c04225
  • Hughey, K.D., A.M. Bradley, R.G. Tonkyn, H.M. Felmy, T.A. Blake, S.A. Bryan, T.J. Johnson, and A.M. Lines. 2020. “Absolute Band Intensity of the Iodine Monochloride Fundamental Mode for Infrared Sensing and Quantitative Analysis.” The journal of physical chemistry. 124(46):9578–9588. doi: 10.1021/acs.jpca.0c07353


  • Lines, A.M., P. Tse, H.M. Felmy, J.M. Wilson, J.C. Shafer, K.M. Denslow, and A.N. Still, et al. 2019. "Online, real-time analysis of highly complex processing streams: Quantification of analytes in Hanford tank sample." Industrial and Engineering Chemistry Research 58(47):21194-21200. doi:10.1021/acs.iecr.9b03636


  • Felmy, H.M., K.T. Bennett, and S.B. Clark. 2017. “The impact of mixed solvents on the complexation thermodynamics of Eu(III) by simple carboxylate and amino carboxylate ligands” The Journal of Chemical Thermodynamics, 114:83-92.