With mountains of waste sitting in bags in simple stores that will inevitably degrade, planning and developing centralized disposal facilities has become a critical issue.
A serious problem is that no debate about how clean is clean enough occurred before the regional cleanup was initiated. The JAEA demonstration projects can be used to develop estimates of cost and other resource requirements — and resulting waste volumes — for defined levels of contaminant reduction, but they cannot be used to specify or justify the numerical goals of the regional cleanup. While we have the tools and knowledge base to develop a more holistic approach to recovery of the evacuated zone, political constraints and public acceptance are as important as technical issues in formulating policy.
Closely associated with the challenge of optimizing remediation is that of understanding how contaminants will behave as a result of natural processes. Will these processes decontaminate affected areas, or recontaminate cleaned ones?
The JAEA has initiated a project to model the future distribution of radioactivity on a regional scale, beginning with field investigations to acquire the data needed to develop conceptual and mathematical migration models of cesium’s environmental behavior. The project includes interdisciplinary Japanese teams, as well as international expertise, which is important for ensuring that the project builds on models that have been used in other contaminated environments, and that it benefits from long-term databases from older incidents that can be used to test models’ predictive power.
Two years after the disaster, Japan still faces many challenges in terms of regional remediation. Not the least of these challenges is to extrapolate future cesium distributions reliably, which is essential to the development of effective monitoring procedures and the formulation of optimal cleanup plans.
Shinichi Nakayama, a researcher in radioactive waste management at the Japan Atomic Energy Agency, has been working on the environmental remediation of Fukushima since the nuclear accident. Ian McKinley, a partner at MCM Consulting, Switzerland, has supported Japanese waste-management projects for more than two decades, most recently as visiting professor at Nagoya and Okayama universities.
Copyright: Project Syndicate