These pathways will allow radionuclides to move from a repository into the environment, accessible to people, animals, and plants. How quickly this happens is important to public safety and health as defined by the regulatory standards set for Yucca Mountain. This test simulates how radioactive particles might move through the rock at Yucca Mountain. No radioactive materials are used in this test, only safe chemical tracers. Sprinklers atop a large block of rock distribute water and tracers.
Sensors monitor the water and tracer movement at the bottom of the block.
If a repository were located here, scientists expect minerals in the rock, called zeolites, to act as a natural barrier, limiting or slowing the movement of radioactive particles. Movement, cracking, and other changes could affect the rock's suitability for housing a repository. Excavation creates pressure on the rock. This test, conducted at several locations, measures how Yucca Mountain rock responds. Aluminum jacks set horizontally inside a test alcove apply force to rock walls.