Exploring the nature of the atom
• Uranium was discovered in 1789 by Martin Klaproth, a German chemist, and named after the planet Uranus.
• Ionising radiation was discovered by Wilhelm Rontgen in 1895, by passing an electric current through an evacuated glass tube and producing continuous X-rays.
• In 1896 Henri Becquerel found that pitchblende (an ore containing radium and uranium) caused a photographic plate to darken. He went on to demonstrate that this was due to beta radiation (electrons) and alpha particles (helium nuclei) being emitted.
• Villard found a third type of radiation from pitchblende: gamma rays, which were much the same as X-rays.
• Then in 1896 Pierre and Marie Curie gave the name ‘radioactivity’ to this phenomenon, and in 1898 isolated polonium and radium from the pitchblende. Radium was later used in medical treatment.
• In 1898 Samuel Prescott showed that radiation destroyed bacteria in food.
• In 1902 Ernest Rutherford showed that radioactivity as a spontaneous event emitting an alpha or beta particle from the nucleus created a different element. He went on to develop a fuller understanding of atoms and in 1919 he fired alpha particles from a radium source into nitrogen and found that nuclear rearrangement was occurring, with formation of oxygen.
• In 1911, George de Hevesy showed that such radionuclides were invaluable as tracers, because minute amounts could readily be detected with simple instruments.
• At the end of 1938 Otto Hahn and Fritz Strassmann in Berlin showed that the new lighter elements were barium and others which were about half the mass of uranium, thereby demonstrating that atomic fission had occurred.
• Lise Meitner and her nephew Otto Frisch, working under Niels Bohr, then explained this by suggesting that the neutron was captured by the nucleus, causing severe vibration leading to the nucleus splitting into two not quite equal parts. They calculated the energy release from this fission as about 200 million electron volts. Frisch then confirmed this figure experimentally in January 1939.
Utilising Nuclear Energy
The Manhattan Project
• June 1942 – The American Army take over the process development, engineering, procurement and site selection for plants to make fissionable materials for an atomic bomb.
• August 1943 – UK government hands over all it’s research on the atomic bomb. The cost of the bomb is estimated at $1,000 million alone.
• Mid-1945 – With assistance from the British team sufficient amounts of Polonium and Uranium are produced at Oak Ridge in the US.
• 16th July 1945 – First atomic device tested successfully at Alamagordo in New Mexico.
• 6th August 1945 – First atomic bomb, which contained U-235, was dropped on Hiroshima.
• 9th August 1945 – second bomb, containing Pu-239, was dropped on Nagasaki. That same day, the USSR declared war on Japan.
• On 10 August 1945 the Japanese Government surrendered.
The Soviet bomb
• Stalin not interested initially in diverting resources to develop an atomic bomb, until intelligence reports suggested that such research was under way in Germany, Britain and the USA.
• 1942 – Stalin initiated a modest research program, with Igor Kuchatov eventually becoming its director in 1943 (basically because most of the other scientists had been sent to the Gulags by a paranoid Stalin!).
• Nov 1945 – The bombing of Hiroshima and Nagasaki gave a higher profile to the Soviet bomb programme and Stalin set up ten secret nuclear cities, the first five of which came online in 1948.
• April 1946 – Additional specialists were brought in to push the programme forward and by August 1947 Soviet scientists had established a test site in Kazakhstan.
• August 1949 – The first test detonation. Work was already being carried out on a hydrogen bomb.
Revival of the ‘nuclear boiler’
• Post WWII – Government focused shifted towards harnessing nuclear energy to make steam and electricity.
• December 1951 – First Nuclear Reactor started at Argonne National Lab in Idaho, USA.
• 1953 – Eisenhower promotes his “Atoms for Peace” program to focus
nuclear research towards energy generation.
• June 1954 – The worlds first plutonium reactor used to produce electrical energy began operating in Obninsk in the Soviet Union.
• 1954 – The US launched their first nuclear powered submarine.
• 1959 – Both the US and the Soviet Union launched their first nuclear-
powered surface vessels.
Nuclear energy goes commercial
• 1960 – Westinghouse and then General Electric start up the first fully operational commercial reactors.
• 1964 – First 2 Soviet nuclear power plants commissioned, which were both started in 1973.
The nuclear power brown-out
• From the late 1970s to about 2002 the nuclear power industry suffered some decline and stagnation. Few new reactors were ordered, the number coming on line from mid 1980s little more than matched retirements
• This was in part due to a number of nuclear accidents, the first at Three Mile Island in New York (1979) and the second at Chernobyl in the Soviet Union (1986).