I have an intel 240 GB 520 series and its activity light remains on constantly. Is this indicative of the drive being accessed constantly and will it in fact reduce the drives life?
This a warranty replacement - the original drive which had failed also had its light on constantly.
That does not mean that the drive is failing. You can check the SSD health by usining this tool: https://downloadcenter.intel.com/download/18455/Intel-Solid-State-Drive-Toolbox Download Intel® Solid-State Drive Toolbox