There are roughly 1.7 million used nuclear fuel rods in Canada, enough to fill five hockey rinks to the top of the boards. The Nuclear Waste Management Organization is considering long term management plans for these rods. At least three management methods will be considered. The first is on-site storage, which has the advantage of avoiding transportation of the fuel bundles. However most of Canada’s reactors are near population centres, and this method would require securing several sites instead of just one. The second option is to store the rods at a central site either above or below ground. One advantage is the rods could be located away from population centres. However transport of nuclear waste poses additional hazards. The third option involves deep geological storage or disposal, likely in the rock of the Canadian shield. An advantage to deep storage or disposal is that the material might pose less of a risk to future generations, but as a disadvantage it would be difficult to remove the fuel if a better disposal method was developed. Also, there is a risk that the waste could over thousands of years leak into the water table and into local ecosystems.

When considering long term management of nuclear waste there are certain uncertainties that cannot be quantified or eliminated. We cannot be sure of the actions of future societies or the effects that occur geologically over long time scales. One method of managing risk and uncertainty is to apply a precautionary principle to decision making processes. There are several different kinds of precautionary principle; in some, one takes no action unless one is sure it will do no harm, or one can follow a precautionary principle allowing one to proceed with a course of action even if the outcome is not certain. Some argue that when a catastrophic risk is involved, the first kind should be used. However in some cases an action must be taken, and so one must determine the course of least harm. Various definitions of the precautionary principle have been suggested. In the Rio Declaration, principle 15 states that where there are threats of serious or irreversible damage, lack of full scientific certainty shouldn’t be used as a reason for postponing cost-effective measures to prevent environmental degradation”. Another definition known as the “Wingspread definition” states that when an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause-and-effect relationships are not fully established scientifically. The exact form of the precautionary principle we use can effect the course of action we choose to follow.

Decision making is made difficult when there is uncertainty as to potential outcomes of the decision. Two sources of uncertainty whose effects cannot be predicted in advance come into play when we are dealing with human systems and natural ecosystems. The first of these, inherent uncertainty due to positive feedback, is a result of the complexity of the systems involved. This effect is best visualized through the metaphor of the butterfly flapping its wings and causing a hurricane. Most of the billions of butterfly flaps will do nothing, but some can cause huge effects, and we cannot in advance know which ones are important. Among other things, such effects limit our ability to predict the weather for a few days in advance. As with the weather, the only way to see which positive feedback cycles will develop in the system we are investigating is to wait and see what develops. Our decisions must be made accordingly.

The other source of uncertainty that clouds our decisions is the unpredictable effect of human technological and social innovation. We cannot know in advance what we will develop in the future and the role these developments will play. Not only can we not know what innovations will appear at what time, but we also can’t know whether they will prove beneficial or prove to have unforeseen consequences. As an example the development of CFCs was seen as a huge breakthrough as they were a safe substitute for the dangerous refrigerant ammonia. However decades later we learned they were destroying the Earth’s fragile and vital ozone layer. Predicting this effect in advance was not possible.

There are a variety of ways we can try to make meaningful decisions in the face of all of this uncertainty. One thing we can do is to set into place mechanisms for ongoing monitoring and to review our decisions as time passes. We must blend proactive behaviour with adaptive behaviour; that is, we mustn’t let uncertainty paralyze us, but we must be willing to adjust decisions as new information becomes available. In an age of complexity, there are no clear-cut solutions, only ongoing processes.

Royal Roads University
Science, Technology & Environment Division
edialogues@royalroads.ca