Story of uranium

Story of uranium
K.S. Parthasarathy
AT the tender age of 15 years, Martin Klaproth dropped out of school. He could not pay his fees. He learnt chemistry from the work benches as an apprentice under an apothecary. He struggled for long hours "in the cramped and unhealthy conditions and the tedium of preparing the raw materials and maintaining the hardware for the crushing, grinding, mixing, boiling and distilling that made up his daily routine".
Later, Martin opened his own business. He could spend more time to do research in analytical chemistry. He analysed all types of materials from various countries. He extracted a new element from a piece of rock, some mine-owner gave him. He called it uranium. He announced the discovery at a meeting of the Royal Prussian Academy of Sciences, Berlin, on September 24, 1789.
Uranium remained virtually useless for several decades; small amounts of uranium added to glass before melting gave the glass a pale-yellowish green hue. Some glass specimens contained up to 25 per cent uranium! Geiger counters screamed when it faced the glass surface.
In 1896, Henri Becquerel discovered that uranium is radioactive .In 1934, Enrico Fermi and his coworkers demonstrated beta activity when they bombarded uranium with neutrons. In 1938, Otto Hahn and Leise Meitner discovered nuclear fission and release of fission neutrons.
On December 2, 1942, Fermi and his team achieved the first self-sustaining nuclear chain reaction in a pile of 400 tons of graphite, six tons of uranium metal and 58 tons of uranium oxide, at the University of Chicago. It produced 0.5 watt of thermal power!
Scientists realised the full potential of uranium when they could design, construct and operate nuclear power reactors 168 years after Klaproth discovered it.
India's tryst with uranium started in 1937 when an English man discovered its presence with copper mineral at Mosabani area. There was apparently no followup on this till late 40s.
Dr Homi Bhabha, the architect of nuclear India, knew the value of uranium. "It must be clearly understood that the possession of sufficient quantities of uranium is a sine qua non for the generation of atomic energy….. So far, no large and concentrated deposits of uranium-bearing minerals have been found in India,……It is essential, therefore, that our immediate programme should include an extensive and intense search for sources of uranium. These geological surveys would take at least two years if carried out in any careful and exhaustive way, and it is possible that their result may be negative. In that case India would either have to depend on an agreement with a foreign power for the purchase of her uranium or go in for the much more costly process of extracting uranium from monazite", Dr Bhabha wrote to Pandit Nehru on April 26, 1948.
Dr Bhabha informed Nehru that the Geological Survey of India under Dr. M.S.Krishnan was organizing surveys for thorium and uranium. He insisted that to ensure secrecy, these surveys should be organised directly under the Atomic Energy Commission and Dr. Krishnan "should be allocated full time to this work"
According to Dr K.S. Koppiker, formerly Head, Uranium and Rare Earth Division, BARC, Indian scientists set up in 1949, the first uranium laboratory in Pedder road, Mumbai, at the residence of Dr Bhabha, where Kenilworth building stands today.
Their neighbours complained that they could not suffer the unbearable releases of acid fumes from the laboratory. In July 1954, scientists shifted the lab to an abandoned godown owned by the Bombay Dyeing Company near Siddhi Vinayak Temple.
Uranium is present in trace quantities in soil, rock, water etc. Typical concentration in soil is about 3 ppm (milligramme per kilo gramme).
(K.S. Parthasarathy is Raja Ramanna Fellow, Department of Atomic Energy)