Glossary of nuclear power plant ageing Plant life management is becoming an increasingly important topic both in nuclear power plant operations and in international discussions on the role of nuclear energy. As in many other aspects of nuclear power plant operations there is much to be learned by international comparisons of practices. This five language glossary of terminology (English French German Russian Spanish) is intended to assist utility operators and regulators in OECD countries and more generally to help readers benefit as much as possible from international experience.