In the case of radioactive elements brought to the surface along with the core samples, the first effect to be considered would be the irradiation of the workers through direct contact with the ‘waste’ samples brought up. Other scenarios impacting a larger group of population can be devised. Direct ingestion of the samples is obviously not to be considered. Direct ingestion through water contamination, however, is conceivable. The drinking water would then have to wash through the sample. Such a scenario is hard to imagine, the more so as the probability that drilling would run precisely through a fuel component is very small. In contrast, the external irradiation hazard must be evaluated, especially for the workers. Safety analyses must include a set of hypotheses concerning the society, in particular the fact that such a scenario implies that knowledge and technologies equivalent to those we have today (deep drilling capability) are available. The discovery of an atypical object should then trigger measurements whose results would naturally lead to limiting the risk solely to the workers on that parti­cular site. In any case the number of potential victims of a serious irradiation will remain small as well as the volume of extracted radioactive material (at most 10~7 of the total deposit).