Irradiation testing of an asphalt-based grout vault sealant

In general, Nokorode 705M (a) showed only minimal effects from irradiation at the levels calculated for a 300-year lifetime, while in contact with the basic fluids expected in actual use. In no instance was loss of adhesion on concrete or loss of water tightness encountered in this testing. In contrast to simpler materials tested over 30 years ago, the Nokorode showed only small changes in density and virtually no changes in the mechanical properties examined. The much higher dose rate used to perform these tests within a reasonable time presumably amplified all irradiation effects, and nevertheless produced no changes which would make the material obviously unsuitable for its intended use. Although the effects observed were not examined in enough detail to determine the dominant degradation mechanism(s), the material is qualified from an engineering point of view