Wastes, radioactive geological considerations

Reducing the effects of radioactivity takes considerable time. For instance, if the aim is to reduce the radioactivity of nuclear waste to the same level as that of the natural uranium ores within a millennium, a typical time length for civilization, it is necessary to consider this issue in conjunction with geological storage of waste. 

The toxicity indices are not measures of hazards, in part because they take no account of the barriers that isolate these wastes from the biosphere or of the behavior of different radioactive elements with respect to these barriers. However, the long-term toxicities of the high-level reprocessing wastes are due to radium, which is the same element that controls the ore toxicity. The long-term radium toxicity of the reprocessing wastes is considerably less than the radium toxicity of the ore. It seems reasonable that high-level wastes can be geologically... 

In analyzing the safety of a waste repository, it is crucial to know the time period under consideration. A number of geologic processes and events are relevant for the safety analysis only if the time frame exceeds a certain range. As it is obvious that the hazard of a waste repository due to the decrease of its radioactive inventory will eventually approach a level that is no longer significant, it will be feasible to estimate a time frame for the safety analysis. This time frame will be called the significant period of the waste repository hazard. The estimation of... 

This experiment provides considerable confidence in the concept of waste immobilization in glass as one step toward isolating the long-lived radioactive by-products of nuclear power from man s environment. Of course, the immobilized material would not be placed deliberately in shallow ground water for permanent disposal. The consensus today is for deep underground disposal in a stable geological formation (21). 

---