A positionism epitomology applied to small group decision-making in radioactive waste management. Doctoral thesis prepared at SCK-CEN and defended in 2004

The article refers to an abstract of a doctoral thesis. Assuring the safety of technological developments is becoming one of the most important tasks in society. For nuclear waste repositories, it is important to know what will remain valuable of current performance and safety assessments within a few hundred years. The core of the PhD concerns the meaning that can be attributed to safety assessments. This study develops a new philosophical theory to explain how small group decision-making on technoscientific problems takes place. It is applied to the specific problem of decision-making on radioactive waste disposal and its related risk assessment. The new philosophical theory is based on Latour's interactionism theory, which in its essence states that facts are only facts if they are accepted by the network. The theory adds that fact-building or decision-making happens in a certain context by interaction of different context elements. The word context has a very specific meaning. It refers to a problem solving situations in which individuals work out a problem framing and use attitudes, personalities, group cultures, and objects. Decisions or fact-building within the group will happen by interaction between these context elements that will get different hierarchical positions and lead to contextual dissonance reduction. This is called positionism. An international questionnaire has been carried out asking for estimations by technologists and scientists of the risks and uncertainties of a high level waste repository on the one hand and their personality, group culture and background characteristics on the other hand. Two important indicators occur. High neuroticism -a personality measure indicating the general tendency to experience affects such as fear, sadness, or distrust- correlates with high assessments of the waste repository risks. Scientists with high confidence in science give significant lower estimations of the repository risks. These results illustrate in a qualitative way the contextual point of view of the philosophical theory. Observations of the Belgian low level waste decision-making process have been made over a period of four years. These observations do not give an historical construction of the process but are used as an illustration of positionism mechanisms. They show that certain argumentations on technology are positioned above others because of contextual aspects. These results illustrate in a qualitative way the positionism theory and its actual applications