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     On average, there are many miles of pipes in a conventional water-cooled nuclear power plant. Maintaining that piping and fining any leaks are very important for the continued safe operation of a plant. Failing pipes can be difficult to identify. There may be a puddle under the pipe, some other evidence of deterioration or a pipe could just burst without any warning. Many nuclear power plants have been in operation for decades and worries about failing pipes is increasing.
    Vanderbilt University researchers are working on the development of an early warning system for problems in the pipes of nuclear power plants. They are coating the inside of pipes with polymer coatings. They have also developed 3D-printed polymer devices that permeated with nanoparticles that function as sensors. These devices can signal changes to the outsides of the pipes.
     Detecting changes to the polymer coating inside a pipe is very challenging.  Kane Jennings is a professor of chemical and biomolecular engineering at Vanderbilt. He said, “The films can chelate metal ions in solution and from a corroding surface. The chelated metals change the properties of the polymer films to effectively cross-link the polymer chains.” Early results of the Vanderbilt team look promising
     A vibrometer is generally a two-beam laser interferometer that measures the frequency (or phase) difference between an internal reference beam and a test beam. The most common type of laser in an LDV is the helium–neon laser, although laser diodes, fiber lasers, and Nd:YAG lasers are also used.
    Virbrometry shows tiny changes when the metals of the pipes are bound to the polymer coatings. Ongoing research is testing the reliability of polymer coatings with different thicknesses. The nanosensors on the outside of the pipes changes color from green to blue. This could signal the beginning of the corrosion process. Jennings said, “Ultimately the sensor would need to interface with the vibrometry to provide a stop/go color signal on the health inside of the pipe.”
     The Electric Power Research Institute carried out a review of the pipe safety at U.S. nuclear power stations. The thirty-six year period covered in the review found one thousand eight hundred and sixteen pipe failures identified by testing and inspection. Another two thousand two hundred and forty-seven pipe failures were discovered after pipes had leaked. Some of these leaks caused the death of workers.
    Pipes in conventional nuclear power plants carry very hot water to the reactor and the spent nuclear fuel pool. Pipes also supply hydrogen gas to generators and transport steam to the turbines that generate electricity. Adding the new detection technology to an operating nuclear power plant would begin with applying polymer coatings to cooling pipe junctions and connections.
    The Vanderbilt research involved both graduate students and faculty in chemical, mechanical and civil engineering. One report on the work was published in the Journal of Materials Chemistry in May 2019. Another report was published in Journal of Physical Chemistry in September 2019. The Vanderbilt project was funded by the U.S. Department of Energy’s Nuclear Energy Enabling Technologies program.