Been there you need to find the security keys one is located in a flooded area on a dead technician(feral) under a desk. The other is located in the other flooded area on a dead technician. You need to activate one of the computers, and start the pumps to clear the first flooded area out after that go back to the now not flooded area, and go into the security area, and unlock the security terminal with the other key, and unlock the overseers office. In the overseers office is a tough tough fight. You best be ready there is like 6 glowing ones, the overseer is a reaver and 2 turrets in his office. Take lots of radx radaway, and a radsuit. The key to the armory is on the overseer. What I did was used a stealth boy, and some spiked knuckles to take a big chunk of health off the overseer. Then i got up on the platform and hurled grenades, and dynamite from there. They can't seem to get you up there Goodluck

turns out, i had most of what i needed to do done, so i can't say for sure what i did, but someones earlier post sounds correct.
for who asked what was in there, a [censored]-ton of goodies including much ammo, multiple rocket launcers, 10mm's, 10mm submachine guns, sniper rifles, grenade launchers, combat and vault 34 armors, a minigun and (drum roll please) the all-american special marksman rifle with red mil-dot reticle sniper scope with a couple rifles to fix it