Rare earth barium copper oxides (REBCO) are a particular class of cuprate high temperature superconductor. The favourable properties of REBCO coated conductor tapes (CCTs) and the well-established production methods have brought these tapes to the forefront of tokamak fusion research, showing a lot of promise for the development of powerful, high field magnets. A current area of research is the effect of irradiation on the functional properties of CCTs. At the UKAEA Materials Research Facility (MRF), a Quantum Design Physical Properties Measurement System (PPMS)® Dynacool™ has recently been installed. The PPMS is a versatile piece of equipment capable of various physical property measurements as a function of magnetic field strength or temperature. The MRF is in the unique position of being able to characterise irradiated/radioactive materials in the PPMS. In this work, measurements in the AC Magnetic Susceptibility operational mode pre- and post-proton irradiation experiments were used to investigate how the functional properties of 2 different CCTs were affected by radiation. The CCT samples were very similar in their overall composition but had different flux-pinning landscapes, and it was this variable which led to differences in performance prior to irradiation and in radiation tolerance. A major conclusion was that future CCTs in fusion applications will need to find a balance between low temperature critical current density enhancement and performance under irradiation.