heavy water

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heavy water

n.
Either of two isotopic forms of water, especially deuterium oxide, consisting chiefly of molecules that contain deuterium instead of protium. Heavy water is used as a moderator in certain nuclear reactors.

heavy water

n
(Elements & Compounds) water that has been electrolytically decomposed to enrich it in the deuterium isotope in the form HDO or D2O

heav′y wa′ter


n.
water in which hydrogen atoms have been replaced by deuterium, used as a nuclear reactor coolant.
[1930–35]

heavy water

Water formed of oxygen and deuterium. Heavy water is much like ordinary water but has higher freezing and boiling points. It is used in certain nuclear reactors for cooling.
Did You Know? How can one drop of water be heavier than another? The answer lies at the atomic level. Normal hydrogen has a nucleus consisting entirely of one proton, around which whirls one electron. However, in a variety of hydrogen called heavy hydrogen or deuterium, a neutron accompanies the proton in the nucleus. Deuterium thus weighs about twice as much as standard hydrogen. The substance we call heavy water is H2O in which many of the hydrogen atoms are replaced by deuterium. Heavy water played a part in the development of the atomic bomb during World War II. It is an excellent absorber of the neutrons that are produced in large quantities in a nuclear chain reaction. It therefore provided a means of regulating the reactions so that they could be studied safely. Once it was shown that a controlled chain reaction was possible, making a device that could create a powerful uncontrolled chain reaction—an atomic bomb—seemed within reach. Heavy water is still found today in nuclear power plants that use natural uranium fuel.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.heavy water - water containing a substantial proportion of deuterium atoms, used in nuclear reactors
moderator - any substance used to slow down neutrons in nuclear reactors
Translations
eau lourde
tungtvann
References in periodicals archive ?
First, I must say that the commandos and partisans who carried out raids on the heavy-water production facility in Norway were heroes of the first order.
The US desire to constrain Iran's heavy-water reactor in the city of Arak was one of the major issues in nearly two years of negotiations between the Big Six and Tehran.
com/article/us-iran-nuclear-araq-idUSKCN0UP1Y120160111) Arak heavy-water nuclear reactor so that it was rendered incapable of producing plutonium.
Asked about Arak heavy-water reactor, Salehi said that Iran is waiting for the endorsement of the fourth document on Arak reactor by the world powers in a bid to ensure that the western countries would fulfill their undertakings.
The Islamic Republic has said that the 40-megawatt, heavy-water plant is aimed at producing isotopes for cancer and other medical treatments, and has denied that any of its nuclear activity is geared to developing weapons.
According to the Telegraph, the images showed that Iran has activated the Arak heavy-water production plant.
The leakage at the Karachi Nuclear Power Plant, commonly known as KANUPP, began around midnight on Tuesday during a routine shut-down for minor repair of a heavy-water channel.
However, heavy-water reactors are facing extinction, said Toronto-based energy consultant Tom Adams.
The new facility will produce uranium fuel for a planned heavy-water nuclear reactor but western powers fear the reactor could eventually be used for producing a nuclear weapon.
Deuterium nuclei's more classical nature makes them stick closer to the oxygen nuclei they're bound to within a heavy-water molecule, Soper says.
In choosing to inaugurate a heavy-water production plant just days before the threat of censure from world powers, President Mahmoud Ahmadinejad signaled that the Islamic republic will not be cowed.