In the civil nuclear industry, long-term storage and deep geological disposal of waste require safety assessments to demonstrate the durability of the materials used. Among these materials, concretes are complex and heterogeneous materials that trap large quantities of free interstitial water. The irradiation of these materials by the confined radionuclides can lead to the accumulation of oxidizing and explosive molecular species. The molecular hydrogen generated by the radiolysis of water presents risks if its concentration in the air exceeds 4% by volume. The air exchange must be continuous and sufficient in a waste containment storage, so that the atmosphere does not become explosive.