Nowadays, CO2 is the primary greenhouse gas pollutant and fossil fuel-fired electrical power plants are the major producer of CO2. In this regard, it is required to equip the electrical power plants with carbon capture and storage (CCS) systems. This paper addresses a multistage generation expansion planning (GEP) including nuclear units, renewable energy units, and different fossil fuel-fired units equipped with CCS. The proposed GEP minimizes the planning costs and CO2 at the same time, while it considers CCS cost and revenue. The problem is mathematically expressed as a constrained, mixed-integer, and nonlinear optimization problem and solved using particle swarm optimization (PSO) algorithm. The problem considers all practical constraints including security constraints of the network, and the generating units constraints of operation. Simulation results demonstrate that utilizing CCS significantly impacts on the planning output. Eventually, a comprehensive sensitivity analysis is carried out based on the CCS cost and revenue.