Darnley Arthur

Please consider the following contribution to the discussion.

Interminable public debate over the question of nuclear waste disposal has been going on for 25 years, seemingly with very little progress. The public at large remains apprehensive about anything to do with radioactivity despite the fact that this phenomenon surrounds us and has always been present in the natural environment since the world began. Unfortunately a large segment of the population seems to believe that radioactivity did not exist prior to the atom bomb and nuclear power. What percentae of the population is aware that potassium is an essential part of living cells and is naturally radioactive? Or realises that when they eat any food containing potassium, such as bananas, they are consuming radioactivity?

Nuclear waste disposal, compared with many other industrial activities that impinge upon the enivronment, is not a major problem from a scientific or engineering point of view. Nuclear waste disposal can be managed as a reverse deep-mining process. In cost or complexity or volume of effluent it does not compare with trying to withdraw excess carbon dioxide from the atmosphere!

There is solid evidence for the above statement. This is provided by the Athabasca basin in northern Sastkatchewan (centred 250 km NE of Fort McMurray). Beneath its surface it has several of the largest and highest grade natural uranium deposits known anywhere in the world containing hundreds of thousands of tons of highly radioactive ore, some deposits averaging more than 10% uranium. Too "hot" to mine by conventional methods - they can be thought of as nature's own waste disposal sites! These deposits contain enough ore to fuel hundreds of nuclear reactors. The uranium in these deposits has been there for more than 1 billion (repeat, 1 billion) years, long before life as we know it existed on the earth, during which time the continents have moved thousands of miles, repeated faulting has occurred (i.e. there have been many earthquakes), the land surface has been up and down relative to sea level many times, there have been several ice ages. The rocks have been saturated with water. Yet despite this long sequence of potentially disruptive events these uranium depoisits are extremely difficult to discover. Why? Because there has been no leakage of radioactivity beyond the immediate vicinity of the ore. This is depite the fact that, theoretically, because the mineralization is assoiated with rock fractures, the location of the mineralization is not ideal from a containment point of view. However, the deposits have been effectively sealed in place because they are surrounded by a clay envelope produced by the mineralizing process.

In order to confirm these observations, please refer to the Radioactivity Map of Canada published by the Geological Survey of Canada in 1986. This shows that the radioactivity of the Athabasca Basin's land surface is significantly below the Canadian average. A more recent North American digital map of surface radioactivity, is about to be published by the IAEA, and this emphasizes the unusually low radiation level of the Athabasca Basin in relation to the continent as a whole.

The conclusion to be drawn from these facts is that it would be quite feasible to insert radioactive wastes back into the same type of geological situation from which uranium ore has been extracted, with considerable confidence that the waste would be safely contained for at least a few hundred million years.

Radioactive waste disposal is not a major problem, not least because the volume of material involved is small compared with many other toxic products which are much more widely dispersed by industry and commerce. A disproportionate amount of time and energy has been devoted to discussing the manageable problems of nuclear waste disposal, meanwhile more intractable problems are being ignored.

I wish this information could be placed in front of the public as frequently as are the statements about the hazardous nature of radioactivity and nuclear energy. A more balanced public debate might then be forthcoming. Having had experience in many countries of the search for radioactive materials, and devices for measuring raioactivity, I am not unaware of the risks.

Arthur G. Darnley, Ph.D

(Geologist; retired Division Director, Geological Survey of Canada; Chair 1976/84 of Joint IAEA/NEA Research Group on Uranium Exploration Methods; Founder, currently Hon. Chair, International Working Group on Global Geotechnical Baselines)

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