Environmental conflicts are a familiar phenomenon in all industrial societies, and social scientists have produced a great number of studies of different environmental conflicts. One conventional way to conceptualize them is known as NIMBY ("not in my backyard"). Although the recent NIMBY literature has revealed the complexity of the issue, the approach continues to be beset by a number of problems. It has been difficult to conceptualize the dynamic character of a conflict from this perspective. This paper suggests that the theory of environmental conflicts should shift in an epistemological and social interactionist direction, toward social constructionist theory. This paper offers a constructionist analysis of three environmental conflicts in Finland. The disputes over the siting of a nuclear waste facility are viewed as processes of perceiving radioactive waste in the different municipalities. The conflicts are examined as struggles over scientific‐technical, economic, and political definitions of the radioactive objects and of the conflicts themselves.