Despite what Bear Grylls claims, your urine is loaded with salts, more concentrated than your body fluids. It requires more water intake to dispose of it. Nobody who knows anything about physiology recommends drinking it in survival situations. That said, it PROBABLY won't kill you, provided that you have access to sufficient potable water. That is, if the urine does not come from a person with hepatitis, UTI, schistosomiasis . . . .