An Optical Analysis of Radiation-Induced Damage in Nuclear Reactor Optical Fibres

There is growing interest in using optical fibres for discrete and distributed measurement of nuclear reactor state parameters such as temperature, water level sensing, neutron flux, etc. online and in real-time. This study looks at optical fibre damage caused by a nuclear reactor’s radiation field. After being exposed to a mixed radiation field from a fission nuclear reactor, we measured the radiation sensitivity of three different fibre options: naked, acrylate coated, ormocer coated fibres.Optical fibres offer numerous advantages, including immunity to electromagnetic interference, high bandwidth, and intrinsic power, making them ideal for use in high radiation environments. However, ionizing radiation can physically damage optical fibres. Optical active defects can be introduced through ionization or atom displacement mechanisms, or via action of pre-existing defects, and can significantly modify the material and device properties. Optical Time Domain Reflectometers (OTDR) can be used to detect dose levels in radiation fields by measuring backscattered light from radiation-generated at the damage centres in the fibre.