|Fig. 1: Calder Hall. The No. 1 reactor control room showing the control desk and the instrumentation. (Source: Wikimedia Commons)|
Britain's nuclear program started in 1946 under the control of the Atomic Energy Research Establishment (incorporated into the United Kingdom Atomic Energy Authority (UKAEA) in 1954), that was civilian in character, but was also tasked with the job of producing the fissile material, initially only plutonium-239, that was expected to be required for a military program.  Development in a large part was driven by a desire to catch up to US and Soviet nuclear capabilities. Though British Scientists contributed to early parts of the Manhattan Project, the McMahon Act of 1946 prevented American technical aid. 
In 1947 the UK's first nuclear reactor was built at Atomic Energy Research Establishment (AERE) Harwell to demonstrate the viability of commercial power reactors. In 1952, with the successful test of UK's first atomic device, known as Operation Hurricane, the UK became the third nuclear power in the world. 
Calder Hall, in Cumbria, England was the world's first nuclear power station to generate electrical power on an industrial scale. It was opened by Queen Elizabeth II on 17 October 1956 and featured four 60 MW reactors. A picture of the control room can be seen in Fig. 1. The Calder Hall design was codenamed PIPPA (Pressurized Pile Producing Power and Plutonium) by the UKAEA to denote the plant's dual commercial and military role.  This is because the facility used Magnox reactors, named as such because the fuel cans were made of magnesium alloy. Their primary purpose was to produce plutonium for Britain's nuclear weapons manufacturing. The production of plutonium from uranium by irradiation in a pile generates large quantities of heat which must be disposed of. Generating steam from this heat, which then runs an electricity generation turbine, is a seen as a free by-product. In total, eleven Magnox power stations were built for this multi-purpose role, although as time passed, electricity generation became the primary purpose for their construction. 
From 1964, Calder Hall was primarily used for commercial electricity generation, and in April 1995 the UK Government announced that all production of plutonium for weapons purposes had ceased. The magnox design was replaced by new advanced gas-cooled reactors, whose sole purpose was electricity production. Calder Hall was shut down in 2003, 47 years after it first opened. At its unveiling, it was seen to represent the start of a "new atomic age" of cheap and plentiful electricity.  At its peak in 1997 a quarter of the UK's electricity came from nuclear power. Since then, however, this share has fallen to a sixth, as ageing reactors have had to shut down.  Environmental, political and economic concerns mean that the future of nuclear energy in Britain is unclear and at risk of further decline. On a brighter note, today the UKAEA researches fusion energy and related technologies, with the aim of positioning the UK as a leader in sustainable nuclear energy. Its flagship project - the Joint European Torus (JET) is home to the world's largest and most advanced nuclear fusion reactor (at least until the Iter reactor in France begins operation in 2020) and has led global efforts to develop a clean, safe energy source for the last 20 years. 
© Aarush Selvan. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
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