Nuclear Power: Decommissioning Risks
After a cooling-off period that could be as long as 50 or more years, nuclear reactors and uranium enrichment facilities must be decommissioned. All waste must be reprocessed or stored, structures decontaminated, and the land, air and water around the site remediated. The period while the plant is being decommissioned may be twice as long as the reactor's operating life.
Nuclear power plants typically have a design life of 40-60 years, whereas it might be more than 100 years after plant closure before decommissioning is completed.