Sizewell nuclear power stations
Encyclopedia
Sizewell nuclear power stations are two nuclear power stations located near the small fishing village of Sizewell
in Suffolk
, England
. Sizewell A, with two magnox
reactors, is now in the process of being decommissioned, while Sizewell B has a single pressurised water reactor and is the UK's newest nuclear power station. A third power station is planned.
.
'4-loop' plant known as SNUPPS
(Standard Nuclear Unit Power Plant System) initially designed in the 1970s and used at Wolf Creek
and Callaway
but with additional redundancy and diversity in the safety systems, and other modifications such as the addition of a passive Emergency Boration System. The containment design was not based on SNUPPS however, but was designed by NNC in conjunction with Bechtel.
The Wolf Creek and Callaway plants each have single half speed, 1,800 RPM (60 Hz), steam turbine-alternator sets which use the steam produced from the heat generated in the reactor to produce about 1,200 MW of electricity at the US grid frequency of 60 Hz. Such large turbo-alternator sets were not available in the UK at the time Sizewell B was designed. So that orders could be given to UK manufacturers, and to avoid project risk in dealing with what were at the time newly designed very large turbo-alternator sets, Sizewell B uses two full speed, 3,000 RPM (50 Hz), nominal 660 MW turbo-alternator sets similar to those used at Drax coal fired power station, and at the last of the AGRs Heysham 2, but adapted to cope with the wetter steam conditions produced by the PWR steam supply system. PWR steam supply systems produce saturated steam at lower temperature and pressure than the dry superheated steam produced by AGR reactors or coal fired power stations, and the high and intermediate pressure stages of the steam turbines have to be designed cope with this. Sizewell B can run at half power using one turbo-alternator.
The major components were supplied by:
A distinctive white hemisphere envelopes the outer shell of the twin-walled Containment building that protects the pressurised water reactor and its steam generators
.
(AGR) based power station, and then in 1974 as a steam-generating heavy water reactor
(SGHWR), Sizewell B was eventually announced as a PWR power station in 1980. The initial design submissions to the CEGB and NII were based on the design of the Trojan
plant at Portland, Oregon. Designed by Westinghouse, construction of Trojan began in 1970 and was completed in 1975. Westinghouse continued to develop the design they had used for the Trojan plant into the SNUPPS design, built first at Callaway, and SNUPPS was adopted as the basis for the design approved by the CEGB in October 1981.
Before construction commenced, the design of Sizewell B was subjected to a detailed safety review by the Nuclear Installations Inspectorate (NII)
, and a lengthy public inquiry. The Pre-Construction Safety Case was submitted to the NII in August 1981. The public inquiry was held between 1982 and 1985, and took over 16 million words of evidence, a record at the time. The chairman of the inquiry, Sir Frank Layfield, reported in early 1987 that, subject to a satisfactory safety case, there were no substantive reasons why the project should not proceed. The Nuclear Installations Inspectorate accepted the Pre-Construction Safety Case and issued a licence to proceed with construction in August 1987.
Sizewell B was calculated to be economically viable at a 5% discount rate and was approved financially on that basis. The project was managed by the CEGB Sizewell B Project Management Team, who declared that it was completed on time and to budget, the final out turn cost being £2,030 million. A 2000 post-startup evaluation estimated generating cost at around 6p/kWh (1.7p/MJ), excluding first of a kind costs but using an 8% discount rate for the cost of capital, or about 8p/kWh (2.2p/MJ) including first of kind costs.
Sizewell B was built and commissioned between 1987 and 1995, and first synchronised with the national grid on 14 Feb 1995.
The original rating was for a thermal power of 3,444 MW and gross electrical output of 1,250 MW, which after house load of 62 MW gave a net output to the grid of 1,188 MW, equivalent to 8.7 TWh in the year of 2005. It was uprated by 1% in 2005 with a thermal power of 3479 MWh (1,127,207,272.1 TJ) and an electrical output of 1,195 MW, though this is dependent on seawater temperature.
As with many other PWRs, Sizewell B operates on an 18-month operating cycle; i.e., at or near 100% output continuously for around 18 months, followed by a month's shutdown for maintenance and refuelling. Sizewell B was designed for a commercial life of 40 years (i.e., to around 2035) but similar stations elsewhere have been granted extensions to 60 years.
On 27 May 2008, the Sizewell B plant had its first unplanned shutdown for over three years, cutting off its supply to the National Grid. A British Energy spokesman said that the fault involved conventional equipment at the plant rather than any part of the nuclear reactor.
On 17 March 2010 Sizewell B was taken offline for an extended period because of high moisture levels in the containment building due to a pressuriser electrical heater fault, requiring difficult repairs. On 2 July 2010 just before 21:00, while still offline, a minor fire broke out on the second floor of the building housing the charcoal absorber at Sizewell B. Numerous emergency services were called to the scene and the fire was brought under control by 3:30 the following day when the charcoal absorber was flooded.
Since the Feb 2009 sale of British Energy to Électricité de France
(EDF), plans for a further twin-unit reactor to be built at Sizewell look increasingly positive and EDF are said to be beginning planning for new reactors in earnest. Sizewell already has a connection agreement in place for a new nuclear power plant to be built. The government revealed that the 1,600 MW projected units, to be called Sizewell C, would, together with the planned units at Hinkley Point
, contribute 13% of UK electricity in the early 2020s. EDF plans to use Areva
's EPR
design for any new build reactors in the UK; the design of reactors currently being built in Finland and France
.
On 18 October 2010 the British government announced that Sizewell was one of the eight sites it considered suitable for future nuclear power stations.
Sizewell
Sizewell is a small fishing village with a few holiday homes in the county of Suffolk, England. It is located on the East Anglian coast just north of the larger holiday villages of Thorpeness and Aldeburgh, and two miles from the town of Leiston. It is within the Suffolk Coast and Heaths AONB.The...
in Suffolk
Suffolk
Suffolk is a non-metropolitan county of historic origin in East Anglia, England. It has borders with Norfolk to the north, Cambridgeshire to the west and Essex to the south. The North Sea lies to the east...
, England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
. Sizewell A, with two 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...
reactors, is now in the process of being decommissioned, while Sizewell B has a single pressurised water reactor and is the UK's newest nuclear power station. A third power station is planned.
Sizewell A
Sizewell B is the UK's only commercial pressurised water reactor (PWR) power station, with a single reactor. It was built and commissioned between 1987 and 1995, first synchronised with the national grid on 14 Feb 1995. The main civil engineering contractor was John Laing plc. The power station is operated by EDF EnergyEDF Energy
EDF Energy is an integrated energy company in the United Kingdom, with operations spanning electricity generation and the sale of gas and electricity to homes and businesses throughout the United Kingdom...
.
Design
The 'nuclear island' at Sizewell B is based on a WestinghouseWestinghouse Electric Company
Westinghouse Electric Company LLC is a nuclear power company, offering a wide range of nuclear products and services to utilities throughout the world, including nuclear fuel, service and maintenance, instrumentation and control and advanced nuclear plant designs...
'4-loop' plant known as SNUPPS
SNUPPS
SNUPPS is an acronym standing for Standardized Nuclear Unit Power Plant System. It refers to a 4-loop PWR reactor design produced by Westinghouse in the 1970s. The design was developed for 4 USA utilities, and plants were built at Callaway and Wolf Creek. The UK plant at Sizewell B was also based...
(Standard Nuclear Unit Power Plant System) initially designed in the 1970s and used at Wolf Creek
Wolf Creek Nuclear Generating Station
Wolf Creek Generating Station, a nuclear power plant located near Burlington, Kansas, occupies 9,818 acres of the total 11,800 acres controlled by the owner...
and Callaway
Callaway Nuclear Generating Station
The Callaway Plant is a nuclear power plant located on a 5,228-acre site in Callaway County, Missouri, near Fulton, Missouri. It began operating on December 19, 1984. The plant, which is the state's only commercial nuclear unit, has one 1,190-megawatt Westinghouse four-loop pressurized water...
but with additional redundancy and diversity in the safety systems, and other modifications such as the addition of a passive Emergency Boration System. The containment design was not based on SNUPPS however, but was designed by NNC in conjunction with Bechtel.
The Wolf Creek and Callaway plants each have single half speed, 1,800 RPM (60 Hz), steam turbine-alternator sets which use the steam produced from the heat generated in the reactor to produce about 1,200 MW of electricity at the US grid frequency of 60 Hz. Such large turbo-alternator sets were not available in the UK at the time Sizewell B was designed. So that orders could be given to UK manufacturers, and to avoid project risk in dealing with what were at the time newly designed very large turbo-alternator sets, Sizewell B uses two full speed, 3,000 RPM (50 Hz), nominal 660 MW turbo-alternator sets similar to those used at Drax coal fired power station, and at the last of the AGRs Heysham 2, but adapted to cope with the wetter steam conditions produced by the PWR steam supply system. PWR steam supply systems produce saturated steam at lower temperature and pressure than the dry superheated steam produced by AGR reactors or coal fired power stations, and the high and intermediate pressure stages of the steam turbines have to be designed cope with this. Sizewell B can run at half power using one turbo-alternator.
The major components were supplied by:
- Reactor System: WestinghouseWestinghouse Electric CompanyWestinghouse Electric Company LLC is a nuclear power company, offering a wide range of nuclear products and services to utilities throughout the world, including nuclear fuel, service and maintenance, instrumentation and control and advanced nuclear plant designs...
- Reactor Vessel: Framatome
- Core Internals: Westinghouse
- Steam Raising: Babcock EnergyDoosan BabcockDoosan Babcock, is part of Doosan Power Systems Ltd a UK-based subsidiary of Doosan Heavy Industries & Construction. DPS is a power sector utility boiler OEM and after market services company, offering specialist services and technologies to clients in the nuclear power generation, fossil-fired...
- Turbines: GEC Alsthom
- Civil works: Laing
- Fuel: BNFLBNFLBritish Nuclear Fuels Limited was a nuclear energy and fuels company owned by the UK Government. It was a former manufacturer and transporter of nuclear fuel , ran reactors, generated and sold electricity, reprocessed and managed spent fuel , and decommissioned nuclear plants and other similar...
A distinctive white hemisphere envelopes the outer shell of the twin-walled Containment building that protects the pressurised water reactor and its steam generators
Steam generator (nuclear power)
Steam generators are heat exchangers used to convert water into steam from heat produced in a nuclear reactor core. They are used in pressurized water reactors between the primary and secondary coolant loops....
.
History
First announced in 1969 as an advanced gas-cooled reactorAdvanced gas-cooled reactor
An advanced gas-cooled reactor is a type of nuclear reactor. These are the second generation of British gas-cooled reactors, using graphite as the neutron moderator and carbon dioxide as coolant...
(AGR) based power station, and then in 1974 as a steam-generating heavy water reactor
SGHWR
Steam Generating Heavy Water Reactor is a pressure tube type, heavy water moderated, light water cooled nuclear reactor. The steam generating heavy water reactor is in principle the same as a BWR but relies on a special heavy water material as the moderator whilst using conventional water as the...
(SGHWR), Sizewell B was eventually announced as a PWR power station in 1980. The initial design submissions to the CEGB and NII were based on the design of the Trojan
Trojan Nuclear Power Plant
Trojan Nuclear Power Plant was a pressurized water reactor nuclear power plant located southeast of Rainier, Oregon, United States, and the only commercial nuclear power plant to be built in Oregon. After sixteen years of service it was closed by its operator, Portland General Electric , almost...
plant at Portland, Oregon. Designed by Westinghouse, construction of Trojan began in 1970 and was completed in 1975. Westinghouse continued to develop the design they had used for the Trojan plant into the SNUPPS design, built first at Callaway, and SNUPPS was adopted as the basis for the design approved by the CEGB in October 1981.
Before construction commenced, the design of Sizewell B was subjected to a detailed safety review by the Nuclear Installations Inspectorate (NII)
NII
NII may refer to one of the following.*National Information Infrastructure, a telecommunications policy buzzword, coined under the Clinton Administration in the United States*Necessary International Initiative...
, and a lengthy public inquiry. The Pre-Construction Safety Case was submitted to the NII in August 1981. The public inquiry was held between 1982 and 1985, and took over 16 million words of evidence, a record at the time. The chairman of the inquiry, Sir Frank Layfield, reported in early 1987 that, subject to a satisfactory safety case, there were no substantive reasons why the project should not proceed. The Nuclear Installations Inspectorate accepted the Pre-Construction Safety Case and issued a licence to proceed with construction in August 1987.
Sizewell B was calculated to be economically viable at a 5% discount rate and was approved financially on that basis. The project was managed by the CEGB Sizewell B Project Management Team, who declared that it was completed on time and to budget, the final out turn cost being £2,030 million. A 2000 post-startup evaluation estimated generating cost at around 6p/kWh (1.7p/MJ), excluding first of a kind costs but using an 8% discount rate for the cost of capital, or about 8p/kWh (2.2p/MJ) including first of kind costs.
Sizewell B was built and commissioned between 1987 and 1995, and first synchronised with the national grid on 14 Feb 1995.
The original rating was for a thermal power of 3,444 MW and gross electrical output of 1,250 MW, which after house load of 62 MW gave a net output to the grid of 1,188 MW, equivalent to 8.7 TWh in the year of 2005. It was uprated by 1% in 2005 with a thermal power of 3479 MWh (1,127,207,272.1 TJ) and an electrical output of 1,195 MW, though this is dependent on seawater temperature.
As with many other PWRs, Sizewell B operates on an 18-month operating cycle; i.e., at or near 100% output continuously for around 18 months, followed by a month's shutdown for maintenance and refuelling. Sizewell B was designed for a commercial life of 40 years (i.e., to around 2035) but similar stations elsewhere have been granted extensions to 60 years.
On 27 May 2008, the Sizewell B plant had its first unplanned shutdown for over three years, cutting off its supply to the National Grid. A British Energy spokesman said that the fault involved conventional equipment at the plant rather than any part of the nuclear reactor.
On 17 March 2010 Sizewell B was taken offline for an extended period because of high moisture levels in the containment building due to a pressuriser electrical heater fault, requiring difficult repairs. On 2 July 2010 just before 21:00, while still offline, a minor fire broke out on the second floor of the building housing the charcoal absorber at Sizewell B. Numerous emergency services were called to the scene and the fire was brought under control by 3:30 the following day when the charcoal absorber was flooded.
Sizewell C
Électricité de France
Électricité de France S.A. is the second largest French utility company. Headquartered in Paris, France, with €65.2 billion in revenues in 2010, EDF operates a diverse portfolio of 120,000+ megawatts of generation capacity in Europe, Latin America, Asia, the Middle East and Africa.EDF is one of...
(EDF), plans for a further twin-unit reactor to be built at Sizewell look increasingly positive and EDF are said to be beginning planning for new reactors in earnest. Sizewell already has a connection agreement in place for a new nuclear power plant to be built. The government revealed that the 1,600 MW projected units, to be called Sizewell C, would, together with the planned units at Hinkley Point
Hinkley Point
Hinkley Point is a headland on the Bristol Channel coast of Somerset, England, five miles north of Bridgwater and five miles west of Burnham-on-Sea, close to the mouth of the River Parrett....
, contribute 13% of UK electricity in the early 2020s. EDF plans to use Areva
Areva
AREVA is a French public multinational industrial conglomerate headquartered in the Tour Areva in Courbevoie, Paris. AREVA is mainly known for nuclear power; it also has interests in other energy projects. It was created on 3 September 2001, by the merger of Framatome , Cogema and...
's 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...
design for any new build reactors in the UK; the design of reactors currently being built in Finland and France
Flamanville Nuclear Power Plant
The Flamanville Nuclear Power Plant is located at Flamanville, Manche, France on the Cotentin Peninsula.It houses two pressurized water reactors that produce 1300 MWe each and came into service in 1986 and 1987, respectively. It produced 18.9 TWh in 2005, which amounted to 4% of the electricity...
.
On 18 October 2010 the British government announced that Sizewell was one of the eight sites it considered suitable for future nuclear power stations.
See also
- 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...
- List of nuclear reactors
External links
- Magnox Limited, Sizewell A
- EDF Energy — Sizewell B
- International Atomic Energy AgencyInternational Atomic Energy AgencyThe International Atomic Energy Agency is an international organization that seeks to promote the peaceful use of nuclear energy, and to inhibit its use for any military purpose, including nuclear weapons. The IAEA was established as an autonomous organization on 29 July 1957...
power station performance data: Sizewell A1, Sizewell A2, Sizewell B - Gallery: Sizewell B from the BBCBBCThe British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...
- Living with Sizewell B and Sizewell B given 10 more years from BBC NewsBBC NewsBBC News is the department of the British Broadcasting Corporation responsible for the gathering and broadcasting of news and current affairs. The department is the world's largest broadcast news organisation and generates about 120 hours of radio and television output each day, as well as online...