A panel in engineering on either the upper or lower deck that opens upon two command keycard authorization nearby. When opened, it becomes active, and opens a panel akin to the nuke's panel where the player can input a code, which would need to be sent in by command, IE headmins, much like the nuke. Once the right code has been entered, the player takes about 20 seconds to arm and activate it. (Could also consider having it create four nuclear bolts that the player "screws in" but that's not totally necessary.) When the self destruct has been activated all ship status will change to reflect this, and a ten minute timer will begin until the ships destruction.
Benefits (How this will benefit the server and game as a whole):
It offers an alternative final solution scenario, similar to the nuke but more relatable to Alien lore. Marines could be evacuating the Sulaco, the halls are overrun, and the final act of the remaining command staff is to activate the self destruct, overloading the SM core in ten minutes.
Details (Description of how you think this would work, the benefits, etc):
Above pretty much covers it.
Implementation (Optional, if you have an idea how to implement it):
Made a concept for the status displays. Kinda want to do more if wanted, it was a fun miniproject.
Side note, I wrote this at 3am, lacking in sleep. I'll probably end up revising this a little more tomorrow.