Hiv remain infectious outside the body? for how long? contact with the urine of a soropositive person in a wound it's a risk?

Wrong question: Nobody ever catches HIV by exposure to infected blood or body fluids in the environment. Whether or how long the survives, or other biological reasons, don't matter. No risk and so no worries. (And by the way, urine never transmits HIV.) If you only have safe sex and don't share drug injection equipment, you will never catch HIV. Don't worry about other possibilities.