CAESAR II stress computations are based on 3d Beam Element theory using nominal pipe dimensions. (If corrosion is being considered, then the corroded section modulus is used).

The pipe cross section used for the stress computation is not adjusted for the presence of a reinforcing pad. If this is what you're after you will have to perform a true FEA evaluation of the tee (using the forces and moments from the CAESAR II local element report).