It urged the department to assume that engineered barriers like concrete and steel would eventually fail, and that most of what was known about the behavior of contaminants in air, soil or water might " eventually be proven wrong ."
12.
Indeed, it is essential to understand this process to guarantee the total containment of HLW waste in an engineered barrier during the first centuries or millennia when the radiotoxicity of the waste is high and when it emits a significant quantity of heat.
13.
Experts are still not certain how fast water will migrate through the rock, what temperature is best for the storage tunnels, how well the storage casks will withstand corrosion, and how much protection would be provided by the geology of the site as opposed to the engineered barriers.
14.
In 1995, the EPA ordered the primary remedy of the burial ground should be : " Containment by capping with an engineered barrier constructed primarily of native materials . " The site is expected to produce no more than a 2 in 10, 000 increase in cancer risk for long term residential use after 320 years, with no significant decrease after that time.
