The Nuclear Blog

For example, if I throw a ball at a glass window one square foot in area, there may be one chance in ten that the window will break, and nine chances in ten that the ball will just bounce. In the physicists’ language this particular window, for a ball thrown in this particular way, has a “disintegration cross-section” of 1/10’th square foot and an “elastic cross-section” of 9/10’ths square foot.                        - Rudolf Peierls explaining cross sections. In our story so far we have atoms, proven to exist with a known size, established by none other than Einstein himself. We have sub-atomic particles, electrons, orbiting at a considerable distance from the protons and neutrons that comprise a densely packed atomic nucleus. We also know that if we hurl neutrons at Uranium the Uranium may split or fission. We also have a good many European, Jewish, scientists who have reason not only to flee in terror but to fear that nowhere is truly safe for them if those who they flee develop

I know not with what weapons World War III will be fought but World War IV will be fought with sticks and stones.                      - Albert Einstein By the time Frank Delano Roosevelt said we have nothing to fear except fear itself at his first inaugural address the structure of the atom was well understood and just six months later the brilliant young Hungarian physicist Leo Szilard had conceived the idea of a nuclear chain reaction driven by a catalyst of neutrons. Outside the English speaking world alarming developments were occurring with a ferocity that accelerated as the decade elapsed. In Germany of 1938, and it’s important to remember NAZI controlled Germany, besides Kristallnacht (the only state sponsored pogrome of destruction of all things Jewish outside Czarist Russia) the Uranium atom, bombarded by neutrons, was first split by Otto Hahn and Fritz Strassmann. To understand why Hahn and Strassmann were shooting neutrons at Uranium we have to go back a little, in 193

Fear it is said “comes from the lack of knowledge and a state of ignorance.“                         -Debasish Mridha In 1897 J. J. Thomson discovered electrons and, in 1904, proposed a ‘plum pudding’ model, where electrons were negative charged particles (plumbs) embedded in a uniform sphere of positive charge (pudding). Now I would like to consider events that transpired just days later, a little more than a year after the Wright Brother’s flight at Kitty Hawk NC. In America Theodore ‘Teddy’ Roosevelt, was inaugurated for his second term, moving further west over one hundred thousand would die in the Russo-Japanese war and (further west still) this would lead to the Russian Revolution. And even further west a young German born, Swiss patent inspector, all of 26 years of age would write four papers on physics, these papers would be of such astounding brilliance and insight that more than a century later we call these four 1905 papers the 'annus mirabilis papers' (miracle y

I do hope this will be the last of this topic for a while, honestly, it's getting pretty dull for me even! I should start where I left off last time, here is a decay chain that happened all the time inside the Hanford nuclear reactors in Hanford Washington during World War II (it happens as well at other reactors but the historical significance of what happened at Hanford is too much to ignore). So what is going on here? Well we start with Uranium (red circle, I've colour coded by type of atom), now natural Uranium is more than 99% U-238, we bombard that Uranium with a neutron (the +n, no charge) that increases the weight by 1, to U-239 and still 92 protons. Then one neutron breaks apart into a proton and an electron (called a Beta particle) the beta is so energetic it zooms off into space, thus beta radiation. The proton sticks around and our atom has one extra proton, so 92+1 = 93, which is Neptunium. A second Beta decay occurs and our Neptunium becomes Plutonium.

There is a lot that I feel needs to be covered still but I really do not want to saddle my poor reader with too much in one sitting, I suspect this will only be the second of many parts on this topic. In the previous post I did allude to the fact that over time the amount of stuff decreases. What exactly is going on? The law of conservation of matter dictates the amount of stuff remains unchanged. Well if we look at say Plutonium 238 (that is the energy source for all of the space vehicles out beyond Mars orbit, and a few inside Mars orbit too) what is happening is the nucleus of the Plutonium atoms are breaking apart. Even in a gram of Plutonium there is going to be 2.53×10 21  plutonium atoms, that is 2.53 sextillion atoms (yes sextillion is a real number it's a thousand times more than a quintillion of course!). Well from here it's an application of the law of big numbers, that is plain old statistics, every so often at random an atom will decay. When exactly is rando

As I am an engineer by training and trade, I feel an important perspective can be gained by listening to a toxicologist. Therefore I am adding the following YouTube video , it's an 80 minute lecture given at the University of South Australia by Professor Geraldine "Gerry" Thomas. Any discussion of nuclear energy or nuclear technology, of any sort, probably should begin by explaining the concept of 'half-life'. Although this is probably well understood by many readers it is a concept that recurs so frequently that I feel if I don't explain this I am doing my readers a disservice. Wikipedia at the time of writing this defines half life as follows: Half-Life  (symbol  t 1⁄2 ) is the time required for a quantity to reduce to half of its initial value. The term is commonly used in  nuclear physics  to describe how quickly unstable atoms undergo, or how long stable atoms survive,  radioactive decay . I guess if you read that a few times it kind of, s