How clean is clean? Does something have to be spotless to be considered “clean” or is it good enough to be “clean enough?” And, if the latter, how good is clean enough? Bringing the matter home – should I insist that my sons’ room be spotless continually, or can I tolerate a little bit of [...]
Radioactive waste disposal is not cheap. When I was a radiation safety officer we spent $10,000 each year to dispose of a fairly small amount of waste, and a few years our disposal bill was closer to $50,000. At another university I worked at we spent over a half million dollars to get rid of [...]
As I discussed in a past posting on uranium enrichment, the uranium we dig out of the ground is unable to sustain a nuclear chain reaction without a lot of coaxing – it has to be immersed in heavy water or surrounded by graphite as opposed to natural (light) water. This is why we enrich [...]
As I mentioned in my first posting on thorium reactors, this is a huge topic that deserves a careful discussion – even four postings isn’t enough to do justice to the topic, but it’s a good start. So this will be my last posting on thorium reactors for now, but I might come back to [...]
Last week I wrote a little bit about how fertile thorium can be turned into reactor fuel. A discussion of how a thorium reactor might differ from a uranium reactor seems a reasonable follow-up topic. The reactors I worked with in the Navy were light-water pressurized water reactors. Like virtually every reactor we have on [...]
Nearly two decades ago I took a short class on nuclear criticality safety – basically a class on how to work safely with things like enriched uranium. When we were reviewing the nuclear properties of U-235 (the isotope of uranium that fissions) I happened to notice that U-233 seemed to have a lot of advantages [...]
Growing up intermittently Catholic, I was taught about Limbo – a sort of antechamber to heaven that holds the souls of those who were never baptized by who had not committed a sin of their own. Those souls in Limbo aren’t admitted to Heaven, but neither are they sent to Hell – they are simply [...]
The unknown frightens us a whole lot more than the known – we can plan on how to deal with hazards we know about while the unknown leaves us unprepared. When my son was young, for example, he was afraid of the dark. Or, rather, he was frightened of the things he could not see [...]
Two billion or so years ago there was a brief moment of time (geologically speaking) when nature managed to make something that would not be seen again until the middle of the last century – a natural nuclear reactor. Earlier and there wasn’t enough oxygen in the atmosphere to mobilize uranium (uranium is only soluble [...]