The story id (sid) field in the database is just a varchar(20). I'm not positive, but I think it may be possible to use any up to 20 character name in there.
Geeklog uses an integer timestamp like identifier, 'YYYYMMDDHHMMSSRRR'. However, I think any unique identifier could work. So if you're willing to experiement you could try 1, 2, 3, 4, etc. or turn the nuke story date into a timestamp similar to the above timestamp.
Good luck,
Vinny