Calder Hall

Calder Hall was a nuclear power station located in Sellafield, Cumbria, England, United Kingdom, and was the world's first commercial nuclear power plant to generate electricity on a large scale, as stated by Harold Macmillan, the then Prime Minister of the United Kingdom, at the United Nations. The plant was designed by Christopher Hinton, and constructed by the United Kingdom Atomic Energy Authority, with the assistance of English Electric, International Combustion, and Head Wrightson. The Calder Hall reactors were of the Magnox design, which was also used in other nuclear power plants in the United Kingdom, such as Chapelcross nuclear power station and Hinkley Point A nuclear power station.

Introduction

The Calder Hall nuclear power station was a significant milestone in the development of nuclear power in the United Kingdom, and was visited by Queen Elizabeth II and Prince Philip, Duke of Edinburgh in 1956. The plant was also a major contributor to the National Grid (UK), providing electricity to Manchester, Liverpool, and other nearby cities, including Preston, Lancashire and Blackpool. The Calder Hall reactors were fueled by natural uranium, and used carbon dioxide as a coolant, similar to the Windscale nuclear power station and Bradwell nuclear power station. The plant was operated by the United Kingdom Atomic Energy Authority, with the assistance of British Nuclear Fuels, and was subject to regulation by the Health and Safety Executive and the Environment Agency.

History

The Calder Hall nuclear power station was commissioned in 1956, and was officially opened by Queen Elizabeth II on October 17, 1956, in the presence of Harold Macmillan, Prince Philip, Duke of Edinburgh, and other dignitaries, including Winston Churchill and Clement Attlee. The plant was designed to generate 50 megawatt of electricity, and was the first commercial nuclear power plant to be connected to the National Grid (UK), supplying electricity to London, Birmingham, and other major cities, including Leeds, Sheffield, and Newcastle upon Tyne. The Calder Hall reactors were also used for plutonium production, and were an important part of the United Kingdom's nuclear weapons program, which was established by the Atomic Energy Act 1946 and the Nuclear Installations Act 1965. The plant was also a major research facility, and was used to develop new nuclear reactor designs, including the Advanced Gas-cooled Reactor and the Sodium-cooled fast reactor.

Design and Operation

The Calder Hall nuclear power station consisted of four Magnox reactors, each with a capacity of 50 megawatt of electricity. The reactors were fueled by natural uranium, and used carbon dioxide as a coolant, which was pumped through the reactor core by electric motor-driven fan (machine)s, similar to those used at the Oldbury Nuclear Power Station and the Wylfa Nuclear Power Station. The plant also used a gas circulator to circulate the carbon dioxide coolant, and a heat exchanger to transfer heat from the reactor to the steam generator. The Calder Hall reactors were designed to operate at a high temperature, and used a graphite moderator to slow down the neutrons and increase the reaction rate, similar to the Chernobyl Nuclear Power Plant and the Fukushima Daiichi Nuclear Power Plant. The plant was operated by a team of highly trained nuclear engineers and nuclear physicists, including Ernest Lawrence, Enrico Fermi, and Niels Bohr.

Safety and Incidents

The Calder Hall nuclear power station had a good safety record, with no major incidents or accidents during its operation, unlike the Three Mile Island accident and the Chernobyl disaster. However, there were some minor incidents, including a fire in one of the reactors in 1957, which was quickly extinguished by the fire brigade, and a leak of radioactive material in 1960, which was contained and cleaned up by the United Kingdom Atomic Energy Authority. The plant was also subject to regular safety inspections and maintenance checks, to ensure that it was operating safely and efficiently, as required by the Nuclear Installations Act 1965 and the Health and Safety at Work etc. Act 1974. The Calder Hall reactors were designed with multiple safety features, including a containment building and a cooling system, to prevent the release of radioactive material into the environment, similar to those used at the Sellafield and the Dounreay.

Decommissioning

The Calder Hall nuclear power station was decommissioned in 2003, after 47 years of operation, and is currently being dismantled and cleaned up by the United Kingdom Atomic Energy Authority and the Nuclear Decommissioning Authority. The plant is being decommissioned in a series of stages, including the removal of the nuclear fuel, the dismantling of the reactors, and the demolition of the containment building, as required by the Nuclear Installations Act 1965 and the Environmental Protection Act 1990. The site is expected to be fully cleaned up and restored by 2120, and will be returned to a greenfield site, similar to the Bradwell nuclear power station and the Berkeley nuclear power station. The decommissioning of the Calder Hall nuclear power station is a complex and challenging process, and requires the use of specialized nuclear engineering techniques and radioactive waste management procedures, as developed by the International Atomic Energy Agency and the World Association of Nuclear Operators. Category:Nuclear power stations in the United Kingdom