DVD burned through Nero has only .nrd file A DVD was given with a .nrd file alone on it (Nero was used to burn videos from a camcorder to the DVD).

Is it possible to recover the video and convert to a mpeg format? Assume acquiring software is not a problem.

I have tried using Nero Burning ROM 2014, but cannot see an option to convert to mpeg format.
I believe NRD is Nero's version of ISO.  Someone likely created the NRD file when authoring the DVD and rather than burning the NRD file to the disk, they burned the file itself on to a disk.  Try doing a burn image with Nero Burning Rom and select the NRD file as the image.