Simultaneous temperature and strain measurements using embedded Fiber Bragg Gratings for real time measurement of surrogate nuclear fuel pellet

Interest has increased in performing real-time measurements of nuclear fuel properties during reactor operation to build the safety case for small modular reactors (SMR). Sensors capable of recording data during reactor operation are expected to expedite the licensing process with nuclear regulators. The Advanced Fuels and Reactor Physics Branch at Canadian Nuclear Laboratories (CNL) has been developing the means of vat polymerization 3D printing of alumina surrogate fuel pellets that contain voids to allow sensors to be embedded within the pellets. Fiber Bragg Gratings inscribed on optical fibers have been chosen as sensors to be tested as they allow for the simultaneous measurement of pellet strain and temperature and are able to operate under high radiation fields. This paper details the simultaneous measurement of temperature and strain of an alumina pellet during bench top, out-of-reactor tests. (author)