The studies you cite were all conducted by the government or by people working under government contracts. Those are the same people who would benefit from selling the casks and waste management services to the government, so they all have an interest in making it look like Yucca Mountain is a safe and effective place to store high-level waste. Maybe it is, but they spent so much time and energy trying to convince us that their credibility is nil. After all, if they're so good at managing the transportation and storage of high-level waste, surely there's no reason they couldn't just fill a few empty warehouses in Detroit or Omaha or Baltimore with the casks, right? Because it's all so safe, right?
You even hint at another reason for skepticism. At best, Yucca Mountain might have a few hundred years of safe and effective storage before there's an accident in transport, a geological event, a leak, or some other event that we've all been told is simply impossible or has a 0.00001% chance of happening in 10,000 years. By that time, all the people responsible for designing and implementing the storage and transport system will be long gone. So there is zero accountability in the process: the people involved could know the waste will be in the groundwater in 100 years and no one responsible would live long enough to stand trial for it. Similarly, they could provide even wholly independent testing labs with cask "samples" that are engineered and manufactured to far higher standards than the production casks would be. By the time anyone discovers this, they're all dead and there are thousands of tonnes of extremely hazardous toxic waste in transport or underground with containment less than called for in the design. Of course, we're told that the government has ways of detecting and preventing these kinds of things from happening, which is why every few years you read about that same government giving its soldiers and sailors defective weapons and armour made by those same government contractors and tested using those same government protocols.
Maybe none of these things is true. Maybe Yucca Mountain really is a great choice, and maybe the casks really will last thousands of years and really can survive being smashed by a train or tossed off the Empire State Building by King Kong. It's a stretch, but it's not impossible. But I don't really believe the people who told us all that, I don't trust them, and no one else who would have had to bear the consequences of failure did, either. Hopefully somewhere there is a town full of people who, like you, have more trust in the government and their contractors and would welcome the opportunity to show the world how a skilled labour force can partner with the federal government and its major contracting corporations to deliver a safe and reliable system for transporting waste to their storage facility and keeping it there without leaks for at least 10,000 years (it really needs to be 100,000, but I'll give you credit for a length of time no greater than that of human history to this point). And after 10,000 years of that skilled labour force and those honest government employees -- I should say governmentS employees, since no government has ever lasted longer than a thousand years or so -- and contracting corporations providing a flawless safety record, your town's water supply, genetic health, and agricultural output will all be every bit as good as they are today. Then our descendents can all agree that the people of Nevada way back in the day sure were a bunch of Nervous Nellies who turned away a golden opportunity to employ a few people for no good reason (and that would really be the only benefit, since the state would get no tax revenue from the facility or its construction as it would all be on government land with government labour and contractors domiciled out of state). That's assuming that anyone 10,000 years from now even knows what Nevada or Yucca Mountain or the United States of America were, or for that matter that there's thousands of tonnes of toxic radioactive waste buried under your town. But hey, all of that might happen, and my long-since-decomposed bones sure will look silly then! THAT's a chance I'm very willing to take, and that was and presumably still is the prevailing attitude in Nevada. The potential cost of being too cautious is nil, especially since the state has no nuclear power facilities and would have gained almost no economic benefit from hosting the dump. What did they have to gain? The potential cost of being too trusting is thousands or even millions of people (your constituents, if you're Harry Reid) dying a horrible death and the long-term contamination of YET MORE of your state's territory. Does it make sense now?
Again, this is not about whether nuclear power is safe or necessary or a good idea. Nor is it even about whether the technically best solution to the problem of existing high-level waste is to bury it under Yucca Mountain as opposed to burying it somewhere else, reprocessing it in fast reactors, glassifying it, shooting it into space, or whatever. It's about whether the people of the State of Nevada acted reasonably and correctly in opposing that solution. I believe very strongly that they did. If you disagree, the government is now giving you an opportunity to put your life and those of your neighbours on the line to prove it. Good!