Deep repositories

It is recognised worldwide that, for high-level and long-lived intermediate-level waste, disposal in stable geological formations is the only way to ensure safety over the necessary long time spans.

This principle is anchored in the Nuclear Energy Act of 2003 and also applies in Switzerland to low- and intermediate-level waste.

In facilities at the surface, the waste can be directly controlled and monitored and is easily retrievable. However, such facilities require ongoing supervision and maintenance. An absolute prerequisite for this is stable societal conditions over the necessary long timescales. In contrast to geological conditions and the evolution of the engineered safety barriers, social and climatic changes cannot be reliably predicted. Geological repositories are therefore preferable.

Illustration: W4

Everyone more or less agrees that toxic wastes have to be handled responsibly.

The generations producing the waste have to take responsibility for its safe management. The concerns of present and future generations have to be taken into consideration. The waste management strategy should not be based on the assumption that social structures will remain stable into the distant future, nor should it assume further technological advances in the field.  

In 1995, the International Atomic Energy Agency (IAEA) issued nine safety principles for handling radioactive waste; these are all based on fundamental ethical considerations. The following two principles in particular are linked directly with the ethical problem. 

Principle 4

Protection of future generations Radioactive waste shall be managed in such a way that predicted impacts on the health of future generations will not be greater than relevant levels of impact that are acceptable today.

Principle 5

Burdens on future generations Radioactive waste shall be managed in such a way that will not impose undue burdens on future generations.

There are only a few alternatives to deep geological disposal of radioactive waste.

For high-level waste (HLW), deep geological disposal is the only viable option. Even if transmutation technology were to function at some time in the future, a deep geological repository would still be required for the remaining waste. The idea continually surfaces that HLW could be shot into space, but the risk of an accident is too high; the waste would fall to the earth's surface with no possibility for control.

For low- and intermediate-level waste (L/ILW), the option of disposal at the surface exists and is already practised in France and Spain. In Switzerland, however, deep geological disposal is also legally prescribed for L/ILW. 

Partial view of the Spanish El Cabril surface disposal facility for low-level waste. Empty disposal compartments can be seen in the front foreground of the photograph. Image: Enresa

Compared to social structures

Rock formations can remain stable over millions of years and maintain their favourable properties. In a suitable underground environment, time effectively stands still, while conditions at the surface undergo repeated change.