This paper presents a radial collection grid optimization approach to support investment decisions into offshore wind power plants (OWPPs). The proposed methodology opportunely combines different optimization criteria and enables trading off cost with power capacity risk (PCR), which is defined as a cumulative power flow summation that reflects the consequences of cable failures. The method strives for a straightforward formulation and solving approach. We define the optimization problem as a mixed-integer linear programming formulation. To construct a relevant case-study, we consider an OWPP from the literature, and validate results via quasirandom Monte Carlo simulations. The numerical results reveal a strong correlation between the proposed PCR and the expected energy not supplied reliability index.