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Showing results for tags 'enrichment'.
I raised an eyebrow at a comment Weaponsman made about the Iranian nuclear program: This isn't true. The vast majority of reactor designs require fuel with varying degrees of enrichment. Natural uranium is only .7% fissile material, and light water reactors typically need around 3% enriched material as fuel. The British CO2-cooled designs need about the same level of enrichment for their fuel. The Soviet RBMK used to be able to use natural uranium, but there was a hasty redesign to make them less explodey, so they cannot anymore and require fuel enriched to 2% or so. Only the CANDU reactor can use natural uranium, and even they often do not because fuel enriched to 2% makes their operation safer and more efficient. Generally speaking, designs that use natural uranium have problems with positive void reactivity coefficients. Some of the Iranian reactors are heavy water units which might be able to use natural uranium, but would be happier and safer using mildly enriched material. However, at least one of their reactors is a light water plant, which would definitely need material to function at all. Fast-neutron reactors require much more enriched fuel, usually upwards of 20% to 50%. That's still far shy of weapons' grade material, however, which is upwards of 85%. Now, I don't expect Weaponsman to know everything; although he knows an awful lot. Seriously; history, asymmetric warfare, weapons, and crypto; he knows a whole lot about those things. So I don't hold it against him at all that he doesn't have in-depth knowledge of nuclear reactor technology. In fact, Weaponsman is usually about the best, most-informed discourse on any matter it is he chooses to write about. In fact, after reading his piece I decided to do a little digging around on various public fora to see what people had to say about nuclear technology. The results were predictable, and I was filled with despair and rage. So-called policymakers clearly do not understand this shit, and it's really easy to understand. I understand it; ergo it cannot be that hard. They're all either lazy or stupid. Nothing that Obama has said about the Iranian nuclear deal gives any indication that he or his speechwriters know what enrichment is or what it does. As for the general public, I'm not convinced that the majority of them know what the word "nuclear" means. Public thinking on nuclear energy is constructed of bad, fuzzy analogies by people who lack familiarity with the most salient facts about it. Take for example this article on the international politics of uranium supply. It's obvious that the people that this article is about, and the people who wrote it are thinking of uranium as being analogous to oil; that in order to use it for power a continuous, large-volume supply of the stuff has got to be secured and guarded. But nuclear fuels are thousands of times more energy dense than chemical ones; with breeder cycles and fuel reprocessing it's hundreds of thousands of times denser, getting on a million times (theoretically it's 1.5 million times denser). That changes everything! Indeed, the technology is slowly approaching the point where it will be economically feasible to produce electrical power from uranium extracted from seawater. The logistics of supplying uranium for power are completely different than for fossil fuels, and they should not be thought of as analogous. Similar failure to comprehend energy density, you know, the thing that makes nuclear energy interesting in the first place, dominates public discourse on nuclear waste disposal, leading to vast overestimations of just how much waste is produced per unit energy. No, you're wrong, that's how fossil fuels work. Anyway, nobody knows what the fuck about anything and everything is fucked.