  In this talk I review the issues of supersymmetry breaking and radion
stabilization in a five dimensional theory compactified on the Z_2 orbifold.
Supersymmetry breaking by Scherk-Schwarz boundary conditions is interpreted as
spontaneous breaking of local supersymmetry by the Hosotani mechanism. The
auxiliary field responsible for spontaneous supersymmetry breaking is inside
the five-dimensional off-shell minimal supergravity multiplet. Different ways
of fixing the supersymmetry breaking order parameter are analyzed. In the
presence of supersymmetry breaking the one-loop effective potential for the
radion has a minimum that fixes its vacuum expectation value. The radion is
stabilized in a metastable Minkowski_4 minimum (versus the AdS_4 vacuum) with a
mass in the meV range making it interesting for future deviations from the
gravitational inverse-square law.
