I’ve been quiet lately on this blog. Why? Because I’ve been wrestling with all the various inventive reactor design strands over the two-plus decades from the first reactor in 1942, and during that time it was never clear how much should live onward in my book and how much I should spit out here. But now I’m gaining clarity (and let me tell you, reactor design is one interesting field … bewilderingly complex but fascinating) and can return to telling you all the bits and pieces that tickle my fancy.
Take a look at the front cover of this book, which came out in 1946 as an immediate reaction to Hiroshima and Nagasaki. I have the 2007 edition reissued by the Federation of American Scientists. What a flotilla of worthies, from Einstein to Oppenheimer! I certainly encourage you to read it but, honestly, I got little out of it for my book.
But I did like the fifteen-page essay titled “The new power” about the possibilities of fission for electricity generation. It’s written by Gale Young, one of the young physicists who worked under Alvin Weinberg during the Manhattan Project and then at postwar Oak Ridge. Apparently he remained active in nuclear reactor work for years but he disappears from my radar soon after penning this introductory essay. I enjoy his light touch as he describes the challenge for the pioneers in devising reactor shielding (don’t you just love the word “romp”?):
Since both neutrons and gamma rays are dangerous to living tissue, both must be shielded against in operating a fission power source. In this respect a fission source is even worse than a radium source; each give out several percent of its energy in the form of dangerous penetrating radiation, but the mixed nature of the fission radiation makes it harder to cope with and requires greater shield thicknesses. For example, lead is effective against gamma rays, but neutrons romp through it with ease; water is good against neutrons since it slows them down and renders them easily absorbable, but it has little stopping power for gamma rays. A thin lightweight shield would be one of the most valuable inventions in the atomic-power field; unfortunately this does not seem to be on the cards.