It actually depends on the NX-OS version running on the switch (and hence the switch model). Starting with version 6.0(2)N2(1), the
default interface command has been added to the nexus world. Compare the release notes of this version.
As far as I know, previous versions do not support this or any similar command.
However you won't be able to run NX-OS 6 or later on the 5010 or 5020 platform, it requires the 55xx platform.