Uranium

More information on uranium mining and its impacts you find on an extra page.

Uranium as a chemical element was discovered in 1789 bei Martin Heinrich Klaproth. 1840 the French chemist Péligot succeeded in producing uranium in metal form. 1896 Henry Becquerel discovered the natural radiation in uranium ore from Joachimsthal. Marie and Pierre Curie 1898 found in the same uranium ore the irradiant elements radium and polonium and formed the term "radioactivity". 1927 for the first time the genetic impact of radioactive rays was detected on Drosophilidae. 1934 Maria Curie dies the aftermath of the radioactive radiation (leukemia). 1938 Otto Hahn discovered together with Fritz Straßmann the uranium's fission and so the theoretic basis of a new energy source enormous extent. With the Manhattan Project in the USA the development of the atomic bomb was forced. 1942 under management of Robert Oppenheimer the first nuclear chain reaction succeeded. In July 1945 the first nuclear explosion took place at the experimental site of Alamogordo in New Mexico (USA). In August 1945 the USA released an atomic bomb on each of the Japanese cities Hiroshima and Nagasaki. In Hiroshima about 100,000 people died immediately, in Nagasaki about 70,000. 1946 the Soviet Union started uranium mining in the Ore Mountains (D). In September 1949 the Soviet Union tested their first atomic bomb. The atomic arms race started. 1952 the United Kingdom detonated their first atomic bomb. 1954 the first atomic power station worldwide was taken into operation in Obninsk near Moscow (SU). The so-called "peaceful" utilization of atomic power started. 1963 the USA and USSR signed a treaty on a partial stop of atomic weapons tests. 526 atomic explosions had taken place on surface by then polluting the environment all-around earth with radioactive fission products of uranium. 1980 more than 17,000 atomic warheads existed on earth. 1985 there are 374 atomic power stations in 26 countries. 1986 in Chernobyl the so far biggest accident in an atomic power station took place. 1986 Mikhail Gorbachev submitted the Soviet proposal to abolish all atomic weapons until the year 2000.

Uranium-238

Natural decay chain of uranium-238

Uranium-238 is not only radiating itself but also produced a series of radioactive daughter elements which all are existing in the ore. The main problems for the surroundings of the ore are radium and radon, because radium binds easily to soluble substances and will be washed out by rain and goes to ground water. Radon is gaseous und leaves the mineral at open surfaces and is in the air to be inhaled. Its half-life is only short, 3.8 days, but it is continuously produced again by radium.

Table 1 Natural decay chain of uranium-238

Nuclide	Half-life	Radiation	Relative activity
Uranium 238	4,5 x 109 y	α γ	100
Th 234	24 d	β γ	100
Pa 234m	1,2 m	β γ	100
U 234	2,5 x 105 y	α γ	100
Th 230	8,0 x 104 y	α γ	100
Radium 226	1622 y	α γ	100
Radon 222	3,8 d	α	100
Po 218	3,05 m	α	100
Pb 214	26,8 m	β γ	100
Bi 214	19,7 m	β	100
Po 214	1,6 x 10-4 s	α γ	100
Tl 210	1,3 m	β γ	100
Pb 210	22 y	β γ	100
Bi 210	5,0 d	β	100
Po 210	138 d	α	100
Tl 206	4,2 m	β	100
Pb 206	stable

The radiations of the nuclides in Table 1 are alpha-, beta- and gamma-rays. Gamma-rays are penetrating matter, they are very similar to x-rays. Beta- and alpha-rays are high energetic particles with electrical charge. All these rays produce mutations in tissues.

Alpha-rays are of high biological effectiveness if they can get into the body via the lungs or into the stomach. Fig.1 shows tracks of single alpha particles sent out by radium. The path length in air is some centimeters, in tissue it would be only 1/1000 of that: some 10 micrometers. They are only dangerous if incorporated.

Finde more articles about Uranium on the Nuclear Heritage Network webpage.

Legal limits for uranium in drinking water

• new regulations in Germany German