To unlock the following, you must beat the respective tour of duty (US, Canada and Britan).
Unlimited Ammo: Beat the game on the Green Difficulty
Unlimited Grenades: Beat the game on the Veteran Diffculty
Unlimited Health: Beat the game on the Hardened Difficulty
How to unlock Survival! Mode
Play and beat the game on Hardened Mode, then it will ask if you want to switch to survival mode. Select yes and it will switch to Survival Mode.