A High Temperature Fiber Optic Raman Probe for Corrosion and Process Monitoring

The ability to monitor the progress of chemical reactions and to detect the presence of corrosive constituents is a challenge in the emerging field of hydrothermal oxidation (HTO) reactors. Likewise, there is also a need to monitor crevice corrosion in commercial steam-generation boilers because corrosion undermines the integrity of steam generators and therefore impacts the operating cost and reliability of a nuclear power plant. In this project, we propose to develop a fiber optic Raman probe that can be used for in situ monitoring of HTO reactors and steam generators. The technical objectives of Phase I program are to identify the optical components needed for a high temperature Raman probe capable of surviving the harsh reactor conditions; propose a Raman probe design with optimum collection efficiency, good silica Raman background rejection, and small enough to fit into the small opening of a pressure vessel; and to investigate window coating materials that will survive the hostile environment of a reactor. The results of Phase I will serve as a foundation for a Phase II program with the objective of the construction of a functioning Raman probe and instrument.