Tunnel Boring Machine daylights at Yucca Mountain
Back 02002 Peter Schwartz wrote a great piece about our visit to the Yucca Mountain Nuclear Waste site. We often refer to it as “the other 10,000 year project”. However 10,000 years is just the legally binding time congress set forth. They actually have a design problem that spans millions of years. This week several people have sent me this excellent write up in BLDG BLOG that features a Q&A with one of the technical architects of the project. Most interesting to me were all the geeky technical details about material choices, climate, and engineering… an excerpt:
At Yucca Mountain we took the attitude that, since we basically have a dry mountain in a dry area with very little rainfall, we would use a material that can stand up to oxygen being present. The material we selected was a metal alloy called Alloy 22. Our design involves basically wrapping the stainless steel packages, in which we would receive the spent fuel, in Alloy 22 and sticking them inside this mountain with a layer of air over the top. What we know is that when water moves through rock or fractured materials, it tends to stay in the rock rather than fall—unless that rock is saturated. Yucca Mountain is unsaturated, so water ought not be a major issue for us at Yucca Mountain—yet it is.
We have to worry about future climates, because, right now in Nevada, we are in a nine year drought—and, basically since the last Ice Age, we have been in a 10,000-year drought. 80% of the time, if we look a million years into the past, we have, on average, twice the precipitation we have now. Most of the past is—and the future will be—wetter and cooler. Which is nice for Nevada! [laughs]
