The axial flow loop reactor pump installed in a polymer unit facilitates slurry circulation in the reactor. The seal cartridge contains a radial bearing for shaft support to ensure stability on the cantilevered pump design. There have been multiple failures in the past with low seal MTBF. The failure analyses conducted indicate similar failure mechanism- seal support bearing failure leading to primary seal leak and subsequent shutdown. To address these vulnerabilities, a Polycrystalline Diamond (PCD) bearing is installed to replace existing spherical roller bearing for the rotor support system inside the mechanical seal cartridge.