Calculation Automates the Decision: Contested Imaginaries of Real-time Radiological Simulation and Probabilistic Risk Assessment for Nuclear Emergency

• In Event: Risks and Standards in the Knowledge Circulation of Science and Technology for Development

Abstract

It is a widespread notion that quantitative calculation of technological risk should help better our decisions concerning risk management and emergency response for nuclear utilization. Both risk assessment techniques and computer simulation systems are believed to be essential for this purpose. After the Fukushima nuclear accident in 2011, the Japanese nuclear community was criticized for failing to digest and implement such "international standards."

After the Fukushima accident, although efforts have been made to fix such insufficiencies, the authors have witnessed highly polarized and stereotyped disputes: probabilistic risk assessments (PRA), or the System for Prediction of Environmental Emergency Dose Information (SPEEDI) are deemed either totally useful, or utterly useless. The imaginaries held by relevant stakeholders on methods of risk quantification and its consequences are contested, but at the same time partly unanimous.

Based on recent publications on the SPEEDI case, which points out the social dysfunction of the "certainty zigzag" situation, a variant of Donald MacKenzie's 'certainty trough' concept, the authors will discuss the negative implications of this situation, such as the obstruction of practical, effective implementation of such technologies. It is suggested that relevant actors with less expertise tend to hold a stronger belief that "calculation should automate decisions and thus prevent regrettable consequences." They deny any flexibility in the interpretation of the outputs of those methods. Taking the disputes concerning PRA together into consideration, the authors will critically discuss a kind of scientism which allowed the failure trajectory of public policy for nuclear emergency preparedness.

Authors

• Kohta Juraku, Tokyo Denki University

• Shin-etsu SUGAWARA, Central Research Institute of Electric Power Industry