Seprom is a special secondary prime ore that is very difficult to obtain but is used to make your ship incredibly powerful. Its' main use is, like mentioned before, to make your ship more powerful, but it can also be used in Skill Tree and Assembly.
Seprom generates 4536 per day (or 189 per hour) with a level 20 Seprom module.
Seprom has a total cargo of 9,079 with a level 20 Seprom module.
After its release, the option to boost Speed generators with seprom existed. This would result in the ship going much faster than originally expected so they just replaced the concept entirely.