Despite significant progress having been achieved in recent years, much remains to be done in terms of addressing the legacies from the early development of nuclear energy, including the dismantling of redundant research and fuel cycle facilities, research reactors and power plants, and the remediation of sites affected by past uranium mining and processing operations. Some countries are moving forward with dealing with these legacies, and accordingly have built up appropriate technical resources and expertise, but many national programmes still face very significant challenges. This publication discusses the barriers that prevent the implementation of decommissioning and environmental remediation (D&ER) projects and provides potential solutions to overcome the identified barriers and thereby facilitates a better implementation of D&ER programmes.