Some factions in the wasteland (like the ghouls at the Reservation or the Brotherhood) would love to get their hands on some weapons-grade uranium. The player can find out what the Ciphers have by speaking with the Nemonik and deducing that his ancestors were carrying uranium around, fixing the computer and accessing the old records, or by being thiefy and snooping around the uranium chamber.
Stealth Boy - Steal the box of enriched uranium from the Storage Cave. A skilled thief would have to disarm the alarm on the uranium chamber door (Traps/Hard) and pick the lock on the door (Lockpick/Hard) or use the key he stole from the Nemonik (Steal/Hard).
Combat Boy - Butcher any Cipher who gets in the way and just take the uranium.
Charisma Boy - Purchase the uranium from the Ciphers (Barter). The Ciphers have no use for the uranium, but because it is within the cave, they know that it is valuable. The price for the uranium will be adjusted depending on how much the PC has helped the Ciphers out in the past, but they won't give it away for free for any reason.
There were two proposed journal entries. One would be the regular entry, and the other would be a "Dumb Journal Entry", presumably the one that would appear for a character with low Intelligence. The entry also shows the different ways of finishing the quest.