Calder Hall Nuclear Power Station
Sellafield site, north of Seascale, Cumbria, UK
Lord Christopher Hinton
date 1953 - 17th October 1956
era Modern |
category Power Generation |
Calder Hall, now undergoing decommissioning, was not just Britain's but also the world's first commercial civil nuclear power station. Reactor No.1 was opened officially by HM Queen Elizabeth II at 12.16GMT on 17th October 1956.
Workington, 24km away, was the first town in the world to receive electricity produced using nuclear power. The power station also produced plutonium for Britain's nuclear weapons. It ceased power generation on 31st March 2003, by which time it was the oldest Magnox station in the world.
The power station was designed by Christopher Hinton, later Lord Hinton, at the behest of Prime Minister Winston Churchill in 1952. The design team was established by the Industrial Group of the Atomic Energy Authority. Work began in 1953 and nuclear power was first transmitted to the UK's National Grid in August 1956 — an astonishingly short construction and commissioning time.
Calder Hall is classified as a quad Magnox station, meaning that it had four Magnox reactors. Magnox (magnesium no oxidation) refers to the metal composition of the nuclear fuel containers, where a magnesium alloy is wrapped around each uranium fuel rod. Fuel rods were supplied by Springfields.
The first two reactors began operating in 1956, the third in 1958 and the fourth in 1959. The original site arrangement was as follows (from south to north) — two cooling towers, Reactor No.1, turbine house and workshops, Reactor No.2.
The reactors were of the gas-cooled graphite-moderated type, and the gas used was carbon dioxide.
Each reactor was housed in a cyclindrical casing made from mild steel, measuring 215m high and 11.3m in diameter. The reactors weighed 33,000 tonnes each and housed 1,696 nuclear fuel channels, all containing five or six fuel elements stacked vertically. Each reactor also had four heat exchangers, generating high and low pressure steam simultaneously.
To generate electricity, the reactors ran eight 3,000 rpm turbines, four located in each of two turbine halls. The turbines were 75m long, 25m high and 20m wide. The site included four hyperbolic concrete cooling towers, 90m high, which were demolished using explosives on 29th September 2007.
Decommissioning is a lengthy procedure and even though consent was granted in June 2005, the process is far from finished. The site covers some 167,000 square metres and included 62 buildings.
At its peak, the station generated 196MW — four times as much power as it did when it opened. According to the British Nuclear Group, in its 47 years of operation, Calder Hall generated enough power to run a three-bar radiator for 2.85 million years!
Civil engineering: Taylor Woodrow Construction Ltd
Pressure vessel design: Whessoe Ltd
Steam turbines and gas circulators: C.A. Parsons Ltd
Steelwork: Alexander Findlay & Co
Machinery: Mathew Hall Ltd
Fuel rods: Springfields
Research: PD, ECPK
"Calder Hall — the story of Britain's first atomic power station" by Kenneth Jay
Methuen & Co. Ltd, London, 1956
Obituary — Sir John Hill (Chairman of UKAEA 1967-81)
The Times, Wednesday 30 January 2008
"The Development of Nuclear Power" by Sir John Cockcroft
Proceedings of the Institution of Civil Engineers, Part 1, Volume 5
November 1955, Number 6, 791-805