Wylfa
Encyclopedia
The Wylfa Nuclear Power Station is situated just west of Cemaes Bay on the island of Anglesey
, North Wales
. Its location on the coast provides an excellent cooling source for its operation. It is named Wylfa as a local resident David Hughes, who went on to become a prominent builder in Liverpool
and build Cemaes Town Hall, had his cottage named Wylfa on the site in the late 19th century.
, Babcock International Group
and Taylor Woodrow Construction, began in 1963. The reactors were supplied by The Nuclear Power Group (TNPG) and the turbines by English Electric
.
It was the second nuclear power station to be built in Wales
, after Trawsfynydd
. Following the closure of Trawsfynydd in 1991, Wylfa is the only nuclear power station in Wales.
Wylfa houses two 490 MW Magnox
nuclear reactor
s, "Wylfa-1" and "Wylfa-2", which were built from 1963 and became operational in 1971.
They have a combined capacity of 980 MW and Wylfa typically supplies 23 GW h
of electricity daily. It is the largest and last reactor of its type to be built in the UK. It was the second British nuclear power station, following Oldbury
, to have a pre-stressed concrete pressure vessel instead of steel for easier construction and enhanced safety.
The original design output was 1,190 MW but unexpected accelerated ("breakaway") corrosion of mild steel components of the gas circuit in hot CO2
was detected even before the first reactor began operating. The channel gas outlet temperature, the temperature at which the CO2 leaves the fuel channels in the reactor core, had to be reduced, initially dropping the power output to 840 MW, which was later raised to 980 MW as more experience accumulated.
The graphite cores each weigh 3800 tonne; 6,156 vertical fuel channels contain over 49,248 natural uranium magnox
-clad fuel elements, hence the name magnox reactor. A further 200 channels allow boron
control rods to enter the reactor and control the nuclear reaction. The primary coolant in the reactors is carbon dioxide
gas.
The power station is operated by Magnox Ltd, formerly Magnox North. The site is owned by the Nuclear Decommissioning Authority
(NDA). Its purpose is to oversee and manage the decommissioning and clean-up of the UK's civil nuclear legacy.
On 20 July 2006 the NDA announced that the station would be shut down in 2010 because operation beyond then would be uneconomic given plans to shut down the Magnox spent fuel reprocessing plant at Sellafield
. However, in 2010 the NDA announced an extension to 2012, beyond Wylfa's 40th anniversary as a generating power station in January 2011.
smelter located in Holyhead
. But the Anglesey Aluminium plant was shut down on 30 September 2009. The company has announced plans for a biomass plant on the site by 2016 for which planning permission has been approved. Wylfa B's proposal has been the subject of much local opposition, led by the group People Against Wylfa B (PAWB – "pawb" is Welsh for "everyone"). Substantial works were needed to strengthen the reactors against deteriorating welds discovered in the safety review in April 2000. Amid public controversy, Greenpeace issued an independent safety appraisal by the nuclear engineering consultancy Large Associates, but the permit to restart operation was given in August 2001. In addition to welding weaknesses, radiolytic depletion of the graphite moderator blocks was still of concern and PAWB continue to campaign for early shut-down of the plant as well as against any nuclear replacement.
Nevertheless, Wylfa continues to provide vital employment to the local area and electricity to the north of Wales, and in March 2006 the local council voted to extend the life of Wylfa A and to support the construction of Wylfa B, citing the potential loss of employment in the smelter works and nuclear station.
Horizon Nuclear Power
, an E.ON
and RWE
joint venture, announced in 2009 intentions to install about 3,000 MWe of new nuclear plant at Wylfa. Horizon is considering building either Areva EPR
or Westinghouse AP1000 reactors at a site to the south of the existing Wylfa station.
On 18 October 2010 the British government announced that Wylfa was one of the eight sites it considered suitable for future nuclear power stations.
Anglesey
Anglesey , also known by its Welsh name Ynys Môn , is an island and, as Isle of Anglesey, a county off the north west coast of Wales...
, North Wales
North Wales
North Wales is the northernmost unofficial region of Wales. It is bordered to the south by the counties of Ceredigion and Powys in Mid Wales and to the east by the counties of Shropshire in the West Midlands and Cheshire in North West England...
. Its location on the coast provides an excellent cooling source for its operation. It is named Wylfa as a local resident David Hughes, who went on to become a prominent builder in Liverpool
Liverpool
Liverpool is a city and metropolitan borough of Merseyside, England, along the eastern side of the Mersey Estuary. It was founded as a borough in 1207 and was granted city status in 1880...
and build Cemaes Town Hall, had his cottage named Wylfa on the site in the late 19th century.
History
The construction of the power station, which was undertaken by British Nuclear Design & Construction (BNDC), a consortium backed by English ElectricEnglish Electric
English Electric was a British industrial manufacturer. Founded in 1918, it initially specialised in industrial electric motors and transformers...
, Babcock International Group
Babcock International Group
Babcock International Group plc is a British-based support services company specialising in managing complex assets and infrastructure in safety-critical and mission-critical environments. Although the company has civil contracts, its main business is with public bodies, particularly the UK...
and Taylor Woodrow Construction, began in 1963. The reactors were supplied by The Nuclear Power Group (TNPG) and the turbines by English Electric
English Electric
English Electric was a British industrial manufacturer. Founded in 1918, it initially specialised in industrial electric motors and transformers...
.
It was the second nuclear power station to be built in Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
, after Trawsfynydd
Trawsfynydd nuclear power station
Trawsfyndd nuclear power station is a disused Magnox power station situated at Trawsfynydd in Gwynedd, Wales.-History:Construction of the power station, which was undertaken by a consortium involving Crompton Parkinson, International Combustion, Fairey Engineering and Richardsons Westgarth, and...
. Following the closure of Trawsfynydd in 1991, Wylfa is the only nuclear power station in Wales.
Wylfa houses two 490 MW Magnox
Magnox
Magnox is a now obsolete type of nuclear power reactor which was designed and is still in use in the United Kingdom, and was exported to other countries, both as a power plant, and, when operated accordingly, as a producer of plutonium for nuclear weapons...
nuclear reactor
Nuclear reactor
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...
s, "Wylfa-1" and "Wylfa-2", which were built from 1963 and became operational in 1971.
They have a combined capacity of 980 MW and Wylfa typically supplies 23 GW h
Hour
The hour is a unit of measurement of time. In modern usage, an hour comprises 60 minutes, or 3,600 seconds...
of electricity daily. It is the largest and last reactor of its type to be built in the UK. It was the second British nuclear power station, following Oldbury
Oldbury nuclear power station
Oldbury nuclear power station is a nuclear power station located on the south bank of the River Severn close to the village of Oldbury-on-Severn in South Gloucestershire, England. It is operated by Magnox North Limited, on behalf of the Nuclear Decommissioning Authority...
, to have a pre-stressed concrete pressure vessel instead of steel for easier construction and enhanced safety.
The original design output was 1,190 MW but unexpected accelerated ("breakaway") corrosion of mild steel components of the gas circuit in hot CO2
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
was detected even before the first reactor began operating. The channel gas outlet temperature, the temperature at which the CO2 leaves the fuel channels in the reactor core, had to be reduced, initially dropping the power output to 840 MW, which was later raised to 980 MW as more experience accumulated.
The graphite cores each weigh 3800 tonne; 6,156 vertical fuel channels contain over 49,248 natural uranium magnox
Magnox (alloy)
Magnox is an alloy—mainly of magnesium with small amounts of aluminium and other metals—used in cladding unenriched uranium metal fuel with a non-oxidising covering to contain fission products in nuclear reactors....
-clad fuel elements, hence the name magnox reactor. A further 200 channels allow boron
Boron
Boron is the chemical element with atomic number 5 and the chemical symbol B. Boron is a metalloid. Because boron is not produced by stellar nucleosynthesis, it is a low-abundance element in both the solar system and the Earth's crust. However, boron is concentrated on Earth by the...
control rods to enter the reactor and control the nuclear reaction. The primary coolant in the reactors is carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
gas.
The power station is operated by Magnox Ltd, formerly Magnox North. The site is owned by the Nuclear Decommissioning Authority
Nuclear Decommissioning Authority
The Nuclear Decommissioning Authority is a non-departmental public body of the United Kingdom formed by the Energy Act 2004. It came into existence in late 2004, and took on its main functions on 1 April 2005...
(NDA). Its purpose is to oversee and manage the decommissioning and clean-up of the UK's civil nuclear legacy.
On 20 July 2006 the NDA announced that the station would be shut down in 2010 because operation beyond then would be uneconomic given plans to shut down the Magnox spent fuel reprocessing plant at Sellafield
Sellafield
Sellafield is a nuclear reprocessing site, close to the village of Seascale on the coast of the Irish Sea in Cumbria, England. The site is served by Sellafield railway station. Sellafield is an off-shoot from the original nuclear reactor site at Windscale which is currently undergoing...
. However, in 2010 the NDA announced an extension to 2012, beyond Wylfa's 40th anniversary as a generating power station in January 2011.
Future nuclear plant plans
A second plant (generally referred to as Wylfa B) has been proposed, in part to provide for the needs of the Anglesey AluminiumAnglesey Aluminium
Anglesey Aluminium Metal Ltd, shut down on 30 September 2009, was a joint venture between Rio Tinto Group and Kaiser Aluminium.Its aluminium smelter, located on the outskirts of Holyhead, was one of the largest employers in North Wales, with 540 staff members, and began to produce aluminium in 1971...
smelter located in Holyhead
Holyhead
Holyhead is the largest town in the county of Anglesey in the North Wales. It is also a major port adjacent to the Irish Sea serving Ireland....
. But the Anglesey Aluminium plant was shut down on 30 September 2009. The company has announced plans for a biomass plant on the site by 2016 for which planning permission has been approved. Wylfa B's proposal has been the subject of much local opposition, led by the group People Against Wylfa B (PAWB – "pawb" is Welsh for "everyone"). Substantial works were needed to strengthen the reactors against deteriorating welds discovered in the safety review in April 2000. Amid public controversy, Greenpeace issued an independent safety appraisal by the nuclear engineering consultancy Large Associates, but the permit to restart operation was given in August 2001. In addition to welding weaknesses, radiolytic depletion of the graphite moderator blocks was still of concern and PAWB continue to campaign for early shut-down of the plant as well as against any nuclear replacement.
Nevertheless, Wylfa continues to provide vital employment to the local area and electricity to the north of Wales, and in March 2006 the local council voted to extend the life of Wylfa A and to support the construction of Wylfa B, citing the potential loss of employment in the smelter works and nuclear station.
Horizon Nuclear Power
Horizon Nuclear Power
Horizon Nuclear Power is a British energy company expecting to build new nuclear power stations in the United Kingdom. It is an E.ON UK and RWE npower joint venture, established in 2009, with its head office in Gloucester....
, an E.ON
E.ON UK
E.ON UK is an energy company in the United Kingdom and a subsidiary of E.ON, the world's largest investor-owned power and gas company. As Powergen, it was listed on the London Stock Exchange and was once a constituent of the FTSE 100 Index but since 1 July 2002 has been owned by E.ON AG of...
and RWE
RWE
RWE AG , is a German electric power and natural gas public utility company based in Essen. Through its various subsidiaries, the energy company contributes electricity and gas to more than 20 million electricity customers and 10 million gas customers, principally in Europe...
joint venture, announced in 2009 intentions to install about 3,000 MWe of new nuclear plant at Wylfa. Horizon is considering building either Areva EPR
European Pressurized Reactor
The EPR is a third generation pressurized water reactor design. It has been designed and developed mainly by Framatome , Electricité de France in France, and Siemens AG in Germany...
or Westinghouse AP1000 reactors at a site to the south of the existing Wylfa station.
On 18 October 2010 the British government announced that Wylfa was one of the eight sites it considered suitable for future nuclear power stations.
See also
- List of nuclear reactors
- Nuclear power in the United KingdomNuclear power in the United KingdomNuclear power currently generates around a sixth of the United Kingdom's electricity. As of 2011, the United Kingdom operates 19 nuclear reactors at nine locations...
- Energy policy of the United KingdomEnergy policy of the United KingdomThe current energy policy of the United Kingdom is set out in the Energy White Paper of May 2007 and Low Carbon Transition Plan of July 2009, building on previous work including the 2003 Energy White Paper and the Energy Review Report in 2006...
- Energy use and conservation in the United KingdomEnergy use and conservation in the United KingdomEnergy use in the United Kingdom stood at 3,894.6 kilogrammes of oil equivalent per capita in 2005 compared to a world average of 1,778.0. In 2008, total energy consumed was 9.85 exajoules - around 2% of the estimated 474 EJ worldwide total...