A three-phase power of \(4000 \mathrm{MW}\) is to be transmitted through four identical \(60-\mathrm{Hz}\) overhead transmission lines over a distance of \(300 \mathrm{~km}\). Based on a preliminary design, the phase constant and surge impedance of the line are \(\beta=9.46 \times 10^{-4} \mathrm{rad} / \mathrm{km}\) and \(Z_{c}=343 \Omega\), respectively. Assuming \(\mathrm{V}_{\mathrm{S}}=1.0\) per unit, \(\mathrm{V}_{\mathrm{R}}=0.9\) per unit, and a power angle \(\delta=36.87^{\circ}\), determine a suitable nominal voltage level in \(\mathrm{kV}\) based on the practical line-loadability criteria.