Natural hazards are high-impact and low-probability (HILP) events, which cause catastrophic consequences on critical infrastructure of the power distribution systems. Reliability analysis has ignored the occurrence of these hazards, leaving power distribution system vulnerable to their deleterious effects. In this paper, a practical framework methodology for the optimal sizing and placement of VAR compensators is presented for voltage regulation enhancement in a power distribution system against the volcanic eruption occurrence. Monte Carlo simulation is used to estimate the unavailability of infrastructure, and by solving the resulting stochastic optimization problem, the optimal placement and sizing of VAR compensator in a power distribution system are achieved. The optimization problem includes a linearized AC optimal power flow model (AC-OPF), including the losses of power lines. The proposed methodology is evaluated in the IEEE 37-node test system, and the results show the efficiency of the proposed methodology.