Gilbert Lewis, a renowned chemist at U. Berkeley, isolated the first sample of essentially pure heavy water from ordinary water in Heavy water is naturally present in ordinary water, so it's more accurate to speak of "isolating" rather than "making" it. Separating out significant quantities, though, is no easy trick because heavy water constitutes only one part in 4, Gilbert Lewis isolated the first samples in using electrolysis—sending an electric current through water to separate it into its elements.
His technique relied on the fact that H 2 0 breaks apart more readily than D 2 0, and the residual water left after electrolysis is relatively rich in D 2 0. By reprocessing the residual water over and over again, he could eventually purify heavy water.
With his lab equipment, however, Lewis's process was time-consuming and expensive. Norsk Hydro, which already used electrolytic cells in the early s to make fertilizer, seized the chance to make heavy water on an industrial scale. By , the Norwegian company was shipping heavy water to scientists throughout Europe who wanted it for physics, chemistry, and biomedical research.
Today, heavy water is isolated in a variety of ways, including a distillation method akin to making brandy from wine. Other methods exploit the different affinities that deuterium and hydrogen have for various compounds. After the Nazis took control of the Norsk Hydro plant in , they expanded the number of electrolytic cells from nine to 18, doubling the plant's production of heavy water.
Dangerous Water. Hitler's Sunken Secret homepage. What is it? How is it Used in Nuclear Power Plants? Why is it Dangerous? What Countries Make It?
Heavy Water D 2 O or deuterium oxide is made up of two atoms of deuterium and one atom of oxygen. Deuterium is a stable isotope of hydrogen with double the mass of hydrogen due to presence of an extra neutron in its nucleus. Deuterium is present in hydrogen and hydrogen bearing compounds like water, hydrocarbons, etc. Heavy Water displays similar physical and chemical properties but differs in nuclear properties when compared to ordinary water which makes it an extremely efficient material for use as moderator and coolant in Pressurized Heavy Water Reactor PHWRs.
Moderator is required in a Nuclear reactor to slow down the neutrons produced during the fission reaction so that the chain reaction can be sustained. Heavy Water is an excellent moderator due to its high moderating ratio and low absorption cross section for neutrons.
Heat energy produced in the core of reactor due to fission reaction is required to be carried away by a coolant. Heavy Water is used as a primary coolant to transport heat generated by the fission reaction to secondary coolant, light water. The light water takes the heat energy from Heavy Water and generates steam at an appropriate pressure for running steam turbines. The most common isotope of hydrogen is called protium, or hydrogen The 1 refers to the total number of protons and neutrons together in a particular isotope.
Hydrogen-1 atoms are made up of a just a single proton and no neutrons. A much rarer isotope of hydrogen is hydrogen-2, or deuterium. Hydrogen-2 atoms are made up of one proton and one neutron. Water is made up of two hydrogen atoms and one oxygen atom, bonded together. In light water — by far the most abundant type of water in nature — the two hydrogen atoms are both of the hydrogen-1 isotope.
In heavy water , the hydrogen atoms are both of the hydrogen-2 isotope. The reason heavy water is important in some types of nuclear reactors also has to do with different isotopes. Uranium has two main naturally occurring isotopes — uranium, with 92 protons and neutrons, and uranium, with 92 protons and neutrons.
Those three neutrons make a huge difference. Uranium cannot sustain a nuclear chain reaction, but uranium can. In naturally occurring uranium, there is vastly more of the uranium isotope than of the uranium isotope. The latter makes up only a fraction of a percent of the overall mass of the ore.
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