Sizewell nuclear power stations#Sizewell B

{{Infobox power station

| name = Sizewell A nuclear power station

| image = Sizewell A.jpg

| image_caption = Sizewell A

| coordinates = {{coord|52.2150|1.6197|region:GB_type:landmark}}

| status = Decommissioning in progress

| country = United Kingdom

| location = Suffolk, East of England

| operator = Magnox

| construction_began = {{start date|1961|04|01}}{{cite web|url=https://pris.iaea.org/PRIS/CountryStatistics/ReactorDetails.aspx?current=235|title=Sizewell A-1|work=Publish Reactor Information System|publisher=IAEA|date=2022-08-29|access-date=2022-08-30}}{{cite web|url=https://pris.iaea.org/PRIS/CountryStatistics/ReactorDetails.aspx?current=236|title=Sizewell A-2|work=Publish Reactor Information System|publisher=IAEA|date=2022-08-29|access-date=2022-08-30}}

| np_reactor_type = GCR - Magnox

| np_reactor_supplier =

| ps_cooling_source = North Sea

| ps_cooling_towers =

| ps_electrical_capacity = {{plainlist|

• 420 MW_e (Net)
• 490 MW_e (Gross)
• 580 MW_e (Design)

}}

| ps_thermal_capacity = 2 × 1010 MW_t

| ps_units_decommissioned = 2 × 210 MW_e

| ps_electrical_cap_fac = {{plainlist|

• Unit 1: 74.7% (lifetime)
• Unit 2: 71.3% (lifetime)

}}

| commissioned = {{plainlist|

• Unit 1: {{start date|1966|01|21|df=y}}
• Unit 2: {{start date|1966|04|09|df=y}}

}}

| decommissioned = {{end date|2006|12|31|df=y}}

| website = {{URL|1=https://magnoxsocioeconomic.com/ssg.php?site=sizewell-a|2=Sizewell A {{pipe}} Magnox Socio-economic scheme}}

| extra = {{gbmapping|TM473633}}

}}

The site of Sizewell A occupies {{convert|245|acre|ha}} north of Sizewell. It is on a low plateau above flood level. The geological foundation comprises Norwich Crag Formation and Red Crag Formation bedrock of Pleistocene age above Eocene London Clay. The Crag deposits predominantly consist of medium dense and dense sands with thin layers of clay and silt and fossiliferous shelly horizons. The Crag strata extend to a depth of {{convert|200|ft}} below ground level. In 1972/73, Sizewell A was awarded the Christopher Hinton trophy in recognition of good housekeeping.

File:Hinton Cup.JPG

The site is reached by road, with the nearest railhead about one mile inland at Sizewell Halt. Sidings were installed at the railhead primarily to transport irradiated elements to the United Kingdom Atomic Energy Authority plant at Sellafield, Cumbria. Nuclear fuel was handled by a crane loading facility at the end of the {{convert|5|mi|adj=on}} Leiston/Sizewell branch railway. This is connected to the East Suffolk line via a south-facing junction to the north of Saxmundham station. The line was extended and used for the delivery of construction materials for Sizewell B power station in the 1980s. The line is now only rarely used for transportation of spent fuels from Sizewell B since the completion of decommissioning of Sizewell A in 2006. A new branch line off the Leiston branch has been proposed for rail terminals for the construction of Sizewell C power station to the north of the existing B power station.{{Cite journal |last=Scotchman |first=Iain C. |date=February 2019 |title=Sizewell-C could generate freight |journal=Modern Railways |volume=76 |pages=17}}

In March 1958 East Suffolk County Council selected the Sizewell site from shortlist to be earmarked for a nuclear power station,{{cite news|title=A-power station site agreement|work= Western Mail |date=5 March 1958|page=6}} and in September the Central Electricity Generating Board announced it would apply for consent to build one there.{{cite news|title=Site for Sixth Nuclear Power Station Chosen|work=Birmingham Post and Gazette|date=30 September 1958 |page=4}} The following February of 1959, the planning committee of Suffolk County Council recommended approval of the plans, and that no public inquiry was necessary.{{cite news|title=Approval of Atom Site|work=Bury Free Press|date=27 February 1959|page=10}} They received two objections (from the headmaster of Sizewell Hall girls school who feared pupils would be subject to "annoying remarks" from workmen,{{cite news|title='unwanted baby'| work=Suffolk and Essex Free Press| date=22 October 1958|page=6}} and from Ipswich Natural History Society).{{cite news|title=School Objects to A-station Plan |work=News Chronicle |place=London | date=20 February 1959|page=3}} In January 1960 the Minister of Power gave consent for the project to proceed.{{cite news|title=Another nuclear Power Station - In Suffolk: Biggest so far|work=Halifax Daily Courier and Guardian|date=27 January 1960|page=5}}

The main construction contract was awarded to British Nuclear Design and Construction Ltd ('BNDC'), a consortium of English Electric, Babcock & Wilcox and Taylor Woodrow Construction,{{Cite web |date=October 2016 |title=Nuclear Development in the United Kingdom |url=https://www.world-nuclear.org/information-library/country-profiles/countries-t-z/appendices/nuclear-development-in-the-united-kingdom.aspx |publisher=World Nuclear Association}} in November 1960.{{cite news|title=Big Nuclear Project|work=Liverpool Echo|date=24 November 1960|page=1}} The initial budget was £56{{nbsp}}million, but due to inflation this figure rose to £65{{nbsp}}million.{{Cite web |date=2 April 2007 |title=Night falls on Sizewell A |url=http://www.neimagazine.com/story.asp?sectionCode=76&storyCode=2043403 |archive-url=https://web.archive.org/web/20070927191120/http://www.neimagazine.com/story.asp?sectionCode=76&storyCode=2043403 |archive-date=27 September 2007 |website=Nuclear Engineering International}} During its 40-year operational lifetime, it had produced {{convert|110|TWh|PJ|abbr=on}} of electricity, which would have been sufficient to meet the domestic needs of England and Wales for six months.{{Cite web |title=Magnox South Sites: Sizewell A |url=http://www.magnoxsouthsites.com/about-us/our-sites/sizewell-a |url-status=dead |archive-url=https://web.archive.org/web/20081211190534/http://www.magnoxsouthsites.com/about-us/our-sites/sizewell-a |archive-date=11 December 2008 |access-date=2 November 2008 |publisher=Magnox South Ltd}} Unit 1 was commissioned on 21 March 1966, and Unit 2 on 15 September. The station was officially opened on 7 April 1967 by the Lord Lieutenant of Suffolk, the Earl of Stradbroke.

The designed net electrical output of the station was 652{{nbsp}}MWe. The power station originally had a single 324.75{{nbsp}}MW turbo-alternator, and a gross generating capability of 327.7{{nbsp}}MW. In 1967 a second turbo-alternator was commissioned with a rating of 275{{nbsp}}MW.CEGB Statistical Yearbook (various dates). CEGB, London. The total generating capacity was reduced to 490{{nbsp}}MW in 1969, and then 420{{nbsp}}MWe in 1973, to arrest the rate of oxidation of internal reactor-core components. At full load, 70{{nbsp}}MWe were used in providing works power from the gross electrical output of 490{{nbsp}}MWe.{{Cite web |date=22 June 2015 |title=Sizewell A |url=https://www.iaea.org/PRIS/CountryStatistics/ReactorDetails.aspx?current=235 |access-date=23 June 2015 |website=Power Reactor Information System |publisher=IAEA}}

The main plant consisted of two 1,010{{nbsp}}MW (thermal) Magnox reactors, which were natural uranium, carbon dioxide gas cooled, graphite moderated units. These supplied heat to eight boiler units, four associated with each reactor. The steam produced by the boilers was fed to two turbo-generators each rated at 325{{nbsp}}MW, but which operated at a reduced capacity of 250{{nbsp}}MW from 1969.

The reactors and turbines were both supplied by English Electric.{{Cite web |title=Nuclear Power Plants in the UK |url=http://www.industcards.com/nuclear-uk.htm |url-status=usurped |archive-url=http://arquivo.pt/wayback/20090719150823/http://www.industcards.com/nuclear%2Duk.htm |archive-date=19 July 2009}}

The foundations for the reactors and associated boilers are provided by a reinforced concrete raft {{convert|8|ft}} thick, founded on the sand with a designed net bearing pressure of 3.5{{nbsp}}tons per square foot. The biological shields are {{convert|100|ft}} high and vary between {{convert|10|and|14|ft}} thick. The composite steel and reinforced concrete cap above each reactor is {{convert|12|ft}} thick. Both reactors were housed in a single building to achieve savings in building costs.

The turbine house is a steel-framed, aluminium clad building {{convert|380|ft}} long, {{convert|160|ft}} wide and {{convert|90|ft}} high, with a reinforced concrete basement {{convert|26|ft}} deep. The foundations are provided by isolated bases and strip footings with a designed maximum bearing pressure of 3 tons per square foot.

The pumphouse which supplied the main turbines with {{convert|27000000|impgal}} of cooling water per hour drew sea water from an intake structure about {{convert|1350|ft}} offshore via twin {{convert|10|ft|adj=on}} diameter tunnels. This water was returned to the sea through similar tunnels discharging {{convert|350|ft}} offshore.

Electricity output from Sizewell A power station over the period 1966-84 was as follows.

Sizewell A annual electricity output GWh.{

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"y": 2748

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"y": 2154

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"y": 2946

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The power station was shut down on 31 December 2006. The Nuclear Decommissioning Authority (NDA) subsidiary Magnox Ltd is responsible for placing contracts for the decommissioning of Sizewell A, at a budgeted cost of £1.2{{nbsp}}billion. Defuelling was completed in 2014.{{cite news | url = https://world-nuclear-news.org/Articles/Defueling-completed-at-Sizewell-A | work = World Nuclear News | title = Defueling completed at Sizewell A

| date = 29 August 2014 | access-date = 13 August 2021}}

Removal of most buildings is expected to take until 2034, followed by a care and maintenance phase from 2034 to 2092. Demolition of reactor buildings and final site clearance is planned for 2088 to 2098.{{Cite web |date=February 2011 |title=The 2010 UK Radioactive Waste Inventory: Main Report |url=http://www.nda.gov.uk/ukinventory/documents/Reports/upload/2010-UK-Radioactive-Waste-Inventory-Main-Report.pdf |url-status=dead |archive-url=https://web.archive.org/web/20120325081518/http://www.nda.gov.uk/ukinventory/documents/Reports/upload/2010-UK-Radioactive-Waste-Inventory-Main-Report.pdf |archive-date=25 March 2012 |access-date=22 May 2012 |publisher=Nuclear Decommissioning Agency/Department of Energy & Climate Change}}

On 7 January 2007, a contractor working on the decommissioning of the station noticed water leaking on to the floor of the laundry where he was washing his clothes. The water was found to be cooling water from the pond that holds the reactor's spent nuclear fuel which had dropped more than {{convert|1|ft|m}} without activating any of the alarms. It is estimated that up to {{convert|40000|impgal}} of radioactive water had leaked from a {{convert|15|ft|adj=on}} split in a pipe, with some spilling into the North Sea. According to the HM Nuclear Installation Inspectorate's report of the incident, without the chance intervention of the contractor, the pond could have drained before the next scheduled plant inspection. If the exposed irradiated fuel had caught fire, it would have resulted in an airborne off-site release of radiation.{{Cite news |last=Gould |first=Mark |date=11 June 2009 |title=Sizewell nuclear disaster averted by dirty laundry, says official report] |work=The Guardian |url=https://www.theguardian.com/environment/2009/jun/11/nuclear-waste-nuclearpower}}

{{Infobox power station

| name = Sizewell B nuclear power station

| status = o

| image = Sizewell B.jpg

| image_caption = Sizewell B

| coordinates = {{coord|52.2150|1.6197|region:GB_type:landmark|display=inline}}

| country = United Kingdom

| location = Suffolk, East of England

| owner = EDF Energy

| operator = EDF Energy

| construction_began = {{start date|1988|07|18|df=y}}{{cite web|url=https://pris.iaea.org/pris/CountryStatistics/ReactorDetails.aspx?current=263|date=2022-08-29|access-date=2022-08-30|title=SIZEWELL B}}

| commissioned = {{start date|1995|02|14|df=y}}

| decommissioned = Planned for 2035

| np_reactors = 1

| np_reactor_type = PWR - SNUPPS

| np_reactor_supplier = Westinghouse

| ps_cooling_source = North Sea

| ps_cooling_towers =

| ps_units_operational = 1 × 1,198 MW_e

| ps_electrical_capacity = {{plainlist|

• 1,188 MW_e (original design)
• 1,198 MW_e (reference net)
• 1,250 MW_e (gross)

}}

| ps_electrical_cap_fac = {{plainlist|

• 82.9% (Lifetime)
• 63.9% (2021)

}}

| ps_thermal_capacity = 1 × 3,425 MW_t

| ps_units_manu_model = GEC-Alsthom

| ps_annual_generation = {{cvt|6709.390|GWh|TJ|abbr=on}} (2021)

| website = {{URL|https://www.edfenergy.com/energy/power-stations/sizewell-b|Sizewell B power station and visitor centre {{pipe}} EDF}}

| extra = {{gbmapping|TM473633}}

}}

Sizewell B is the UK's only commercial pressurised water reactor (PWR) power station. Its single reactor was built and commissioned between 1987 and 1995, and first synchronised with the national grid on 14 February 1995. The main civil engineering contractor was John Laing. The power station is operated by EDF Energy. The architectural design was carried out by Yorke Rosenberg Mardall.{{Cite news |date=2006 |title=Sizewell Stories |publisher=Building |url=http://www.building.co.uk/sizewell-stories/3069773.article |access-date=30 March 2016}}

EDF's strategic target is for a 20-year life extension for Sizewell B PWR, beyond the current accounting closure date of 2035.{{Cite news |date=20 February 2012 |title=EDF plans longer life extensions for UK AGRs |publisher=Nuclear Engineering International |url=http://www.neimagazine.com/story.asp?storyCode=2061782 |url-status=dead |access-date=16 May 2012 |archive-url=https://web.archive.org/web/20131013200355/http://www.neimagazine.com/news/newsedf-plans-longer-life-extensions-for-uk-agrs |archive-date=13 October 2013}} This would mean the plant remaining in operation until 2055. EDF reaffirmed this plan in December 2024.{{cite news | url = https://www.theguardian.com/environment/2024/dec/04/four-of-uks-oldest-nuclear-plants-to-run-for-even-longer-as-hinkley-point-delayed | title = Four of UK’s oldest nuclear plants to run for even longer as Hinkley Point delayed | first1 = Jillian | last1 = Ambrose | date = 4 December 2024 | access-date = 4 December 2024}} {{As of|2022}}, the power station is still planned to close in 2035.{{cite web | url = https://www.gov.uk/guidance/sizewell-nuclear-regulation | title = Sizewell: nuclear regulation | publisher = Environment Agency | date = 24 January 2020 | access-date = 26 March 2022}} However, a government official is cited stating that "it probably will be extended", while EDF intends to take a final decision on the estimated investment of £500-£700{{nbsp}}million in 2024.{{cite web |url=https://www.ft.com/content/51d4ff8c-f0c0-4082-8db6-11c031be1420 |title=UK looking to extend life of nuclear plant by 20 years amid energy crisis - |publisher=Financial Times |date=14 March 2022 |access-date=4 January 2024}}

The nuclear island at Sizewell B is based on a Westinghouse 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 (National Nuclear Corporation – bought by Amec Foster Wheeler in 2005) in conjunction with Bechtel.

The Wolf Creek and Callaway plants each have single half speed, 1,800{{nbsp}}RPM (60{{nbsp}}Hz), steam turbine-alternator sets which use the steam produced from the heat generated in the reactor to produce about 1,200{{nbsp}}MW of electricity at the US grid frequency of 60{{nbsp}}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{{nbsp}}RPM (50{{nbsp}}Hz), nominal 660{{nbsp}}MW turbo-alternator sets similar to those used at the AGR power stations Hinkley Point B, Heysham 1, Hartlepool and Torness, and at some fossil-fuel power stations elsewhere, 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 fossil-fuel power stations, and the high- and intermediate-pressure stages of the steam turbines have to be designed cope with this.{{Cite book |last=Leyzerovich |first=Alexander |title=Wet-steam Turbines for Nuclear Power Plants |date=2005 |publisher=PennWell |isbn=978-1-59370-032-4 |pages=23, 24}} Sizewell B can run at half power using one turbo-alternator.{{Cite web |title=Sizewell: Nuclear station running at half power after turbine taken offline |url=http://www.eadt.co.uk/news/sizewell_nuclear_station_running_at_half_power_after_turbine_taken_offline_1_1128043?ot=archant.PrintFriendlyPageLayout.ot |access-date=13 November 2011 |website=East Anglian Daily Times}}

The major components were supplied by:{{Cite web |last=Pick |first=Malcolm |date=9 June 2004 |title=United Kingdom LWR Activities (IAEA Vienna presentation) |url=http://www.iaea.org/OurWork/ST/NE/NENP/NPTDS/Downloads/TWG2004_LWRHWR/uk.pdf |access-date=2 August 2011 |website=BNFL}}{{dead link|date=May 2018 |bot=InternetArchiveBot |fix-attempted=yes }}

• Reactor system: Westinghouse
• Reactor vessel: Framatome (main shell: Japan Steel Works, domes and other components: Le Creusot Forge){{Cite report |url=https://cdn.greenpeace.fr/site/uploads/2017/02/R3233-R1-FINAL-19-09-16.pdf |title=Irregularities and Anomalies Relating to the Forged Components of Le Creusot Forge |last=Large |first=John |date=26 September 2016 |publisher=Greenpeace France |page=24 |access-date=7 April 2022 |work=Large Associates}}
• Core internals: Westinghouse
• Steam raising: Doosan Babcock
• Turbines: GEC-Alsthom
• Civil works: John Laing
• Fuel: Springfields Nuclear Fuel
• Architect: Yorke Rosenberg Mardall

A distinctive white hemisphere envelopes the outer shell of the twin-walled containment building that protects the pressurised water reactor and its steam generators.

First announced in 1969 as an advanced gas-cooled reactor (AGR) based power station,{{Cite news |last=Aldous |first=Tony |date=30 October 1969 |title=Government agree to £400m power stations programme |page=1 |work=The Times |issue=57704 |url=https://www.thetimes.com/archive/article/1969-10-30/21/1.html}}{{Cite news |date=30 October 1969 |title=Steep penalties for drug traffickers: four power stations approved |page=5 |work=The Times |issue=57704 |url=https://www.thetimes.com/archive/article/1969-10-30/5/1.html |id=col A}} and then in 1974 as a steam-generating heavy water reactor (SGHWR), Sizewell B was eventually announced as a PWR power station in 1980.{{Cite news |last1=Hirst |first1=Nicholas |last2=Wright |first2=Pearce |date=2 October 1980 |title=Electricity board confirms that it intends to build pressurized water reactors on site in Suffolk |page=5 |work=The Times |issue=60739 |url=https://www.thetimes.com/archive/article/1980-10-02/5/1.html |id=col A}} The initial design submissions to the CEGB and the Nuclear Installations Inspectorate (NII) were based on the design of the Trojan plant at Portland, Oregon.{{Cite news |last=Wright |first=Pearce |date=30 July 1977 |title=Government advised not to develop UK-designed reactor |page=2 |work=The Times |issue=60069 |url=https://www.thetimes.com/archive/article/1977-07-30/2/1.html}}{{Cite news |last=Wright |first=Pearce |date=23 April 1981 |title=Safety systems are doubled in proposed new nuclear power plant |page=4 |work=The Times |issue=60909 |url=https://www.thetimes.com/archive/article/1981-04-23/4/5.html}} 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.{{Cite news |last=Cookson |first=Clive |date=24 October 1981 |title=Design approved for first PWR reactor |page=15 |work=The Times |issue=61064 |url=https://www.thetimes.com/archive/article/1981-10-24/15/19.html}}

Before construction commenced, the design of Sizewell B was subjected to a detailed safety review by the 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{{nbsp}}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 cost was revised upwards three times to 135% of the original cost, providing a cost-performance of £2,250/kW (2000 prices) not including first of a kind costs and £3,000/kW including them. A post-startup evaluation estimated generating cost were about 6p/kWh (2000 prices, equivalent to £{{Inflation|UK|60|2000}}/MWh in {{Inflation/year|UK}}), excluding first-of-kind costs but using an 8% discount rate for the cost of capital, much higher than the expected cost in 1995 of 3.5p/kWh (2000 prices, equivalent to £{{Inflation|UK|35|2000}}/MWh in {{Inflation/year|UK}}).{{Cite web |author=Performance and Innovation Unit |website=PIU Energy Review Working Paper |date=February 2002 |title=The Economics of Nuclear Power |pages=6-7 |url=http://www.cabinetoffice.gov.uk/media/cabinetoffice/strategy/assets/pii.pdf |publisher=Cabinet Office |archive-url=http://webarchive.nationalarchives.gov.uk/20081229193356/http://www.cabinetoffice.gov.uk/media/cabinetoffice/strategy/assets/pii.pdf |archive-date=29 December 2008 |access-date=2 June 2009}}

File:Sizewell B reactor dome - geograph.org.uk - 1396226.jpg

Sizewell B was built and commissioned between 1987 and 1995, and first synchronised with the National Grid on 14 February 1995. The cost of Sizewell B has been quoted as £2{{nbsp}}billion (1987 prices) with a quarter of that cost being related to civil engineering works.{{cite web |title=Sizewell B |url=https://www.ice.org.uk/what-is-civil-engineering/what-do-civil-engineers-do/sizewell-b/ |website=Institution of Civil Engineers |access-date=27 June 2023 |archive-url=https://web.archive.org/web/20230102042121/https://www.ice.org.uk/what-is-civil-engineering/what-do-civil-engineers-do/sizewell-b/ |archive-date=Jan 2, 2023 |language=en |url-status=live}}

The original rating was for a thermal power of 3,444{{nbsp}}MW and gross electrical output of 1,250{{nbsp}}MW, which after house load of 62{{nbsp}}MW gave a net output to the grid of 1,188{{nbsp}}MWe, equivalent to {{convert|8.7|TWh|PJ|abbr=on}} in the year of 2005. It was uprated by 1% in 2013 with a thermal power of 3,479{{nbsp}}MW and an electrical output of 1,195{{nbsp}}MWe,{{Cite web |date=22 June 2015 |title=Sizewell B |url=https://www.iaea.org/PRIS/CountryStatistics/ReactorDetails.aspx?current=263 |access-date=23 June 2015 |website=Power Reactor Information System |publisher=IAEA}} 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, Sizewell B had an unplanned shutdown, cutting off its supply to the National Grid.{{Cite news |date=27 May 2008 |title=Sizewell nuclear plant shut down |work=BBC News |url=http://news.bbc.co.uk/1/hi/uk/7422817.stm |access-date=27 May 2008}} 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.{{Cite news |date=11 June 2010 |title=Sizewell B outage will extend into summer |work=Nuclear Engineering International |publisher=Progressive Media International |url=https://www.neimagazine.com/news/newssizewell-b-outage-will-extend-into-summer/ |access-date=6 July 2010}} 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 adsorber 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 adsorber was flooded.{{Cite news |date=3 July 2010 |title=Fire breaks out at nuclear power plant near Leiston |work=BBC News |url=http://news.bbc.co.uk/1/hi/england/suffolk/10498164.stm}}

On 2 March 2012, Sizewell B had an unplanned shutdown due to an electrical fault. One and a half weeks later it was restarted at half capacity.{{Cite news |date=13 March 2012 |title=Sizewell B: Nuclear plant back up and running after shut down |work=East Anglian Daily Times |url=http://www.eadt.co.uk/news/sizewell_b_nuclear_plant_back_up_and_running_after_shut_down_1_1235361}} {{asof|2012|6}}, conditions improved and Sizewell B continued under carefully controlled operation.

In 2013, a new remote Emergency Response Centre was inaugurated near the power station, following recommendations made after the Fukushima Daiichi nuclear disaster. The centre provides remote controls and a back-up plant.{{Cite news |date=19 December 2013 |title=EDF Energy inaugurates Sizewell B emergency response centre, hints about Dungeness B life extension |work=Nuclear Engineering International |publisher=Progressive Media International |url=http://www.neimagazine.com/news/newsedf-energy-inaugurates-sizewell-b-emergency-response-centre-hints-about-dungeness-life-extension-4149353 |access-date=21 December 2013}}

In January 2014, the building of a dry spent nuclear fuel store began. The existing spent fuel pool, which stores spent fuel under water, was expected to reach full capacity in 2015.{{Cite news |date=23 January 2013 |title=Sizewell builds dry spent nuclear fuel store |work=Nuclear Engineering International |publisher=Progressive Media International |url=https://www.neimagazine.com/news/newssizewell-builds-dry-spent-nuclear-fuel-store/ |access-date=26 January 2013}} In April 2016, the building was inaugurated. This will enable spent nuclear fuel produced from autumn 2016 until at least 2035 to be stored until a deep geological repository is available.{{Cite news |date=5 April 2016 |title=EDF Energy completes 'dry fuel store' at Sizewell B |work=World Nuclear News |publisher=World Nuclear Association |url=http://www.world-nuclear-news.org/WR-EDF-Energy-completes-dry-fuel-store-at-Sizewell-B-05041601.html |access-date=6 April 2016}} In March 2017, the first cask containing spent nuclear fuel was installed.{{Cite news |date=23 March 2017 |title=First cask emplaced at Sizewell B fuel store |work=World Nuclear News |publisher=World Nuclear Association |url=http://www.world-nuclear-news.org/WR-First-cask-emplaced-at-Sizewell-B-fuel-store-2303175.html |access-date=23 March 2017}}

In 2021, Sizewell B had an extended outage for maintenance and safety related issues. The Times reported that excessive wear on some stainless steel "thermal sleeves" in the control rod mechanisms had been discovered. The maintenance period was extended to over four months to evaluate the cause and extent of the wear to decide how many to replace.{{cite news |url=https://www.thetimes.com/business-money/energy/article/sizewell-b-nuclear-plant-forced-to-stay-shut-over-safety-concerns-0d9l2mkkq |title=Sizewell B nuclear plant forced to stay shut over safety concerns |last=Gosden |first=Emily |newspaper=The Times |location=London |url-access=subscription |date=17 May 2021 |access-date=17 May 2021}}

{{Main|Sizewell C nuclear power station}}

Image:DSCN1362-view-to-sizewell-along-beach crop 800x400.jpg

Since the sale of British Energy to Électricité de France (EDF) in February 2009, plans for a further twin-unit reactor to be built at Sizewell have looked increasingly likely.{{Cite web |date=24 September 2008 |title=New dawn for UK nuclear power |url=http://www.world-nuclear-news.org/NN_New_dawn_for_UK_nuclear_power_2409081.html |access-date=25 September 2008 |publisher=WNN}} Sizewell already has a connection agreement in place for a new nuclear power plant to be built.{{Cite web |date=24 September 2008 |title=EDF confirms £12.5bn offer for British Energy |url=http://www.newenergyfocus.com/do/ecco.py/view_item?listid=1&listcatid=32&listitemid=1723 |url-status=usurped |archive-url=https://web.archive.org/web/20160630175219/http://www.newenergyfocus.com/do/ecco.py/view_item?listid=1&listcatid=32&listitemid=1723 |archive-date=30 June 2016 |access-date=25 September 2008 |publisher=New Energy Focus}} The government revealed that the 1,600{{nbsp}}MW projected units, to be called Sizewell C, would, together with the planned units at Hinkley Point C, contribute 13% of UK electricity in the early 2020s. EDF plans to use Framatome's EPR design for any new-build reactors in the UK, this being the design of reactors currently being built in Olkiluoto, Finland, Flamanville, France and Taishan, China.

On 18 October 2010, the British government announced that Sizewell was one of the eight sites which it considered suitable for future nuclear power stations.{{Cite news |date=18 October 2010 |title=Nuclear power: Eight sites identified for future plants |work=BBC News |publisher=BBC |url=https://www.bbc.co.uk/news/uk-politics-11564152 |access-date=18 October 2010}}

On 21 October 2015, it was reported that Britain and China had reached Strategic Investment Agreements for three nuclear power plants, including one at Sizewell,{{Cite web |date=21 October 2015 |title=Hinkley Point nuclear agreement reached |url=https://www.bbc.com/news/business-34587650 |website=BBC News}} though no specific financing plans for Sizewell are agreed.{{Cite news |last=Leroux |first=Marcus |date=16 September 2016 |title=Hinkley is no pointer to funding for Sizewell |work=Sunday Times |location=London |url=https://www.thetimes.com/business-money/energy/article/hinkley-is-no-pointer-to-funding-for-sizewell-g2vbnmk3b |url-access=subscription |access-date=30 October 2016}} The final investment decision for Sizewell C is only likely to take place after the Hinkley Point C build has started.{{Cite news |last=Cornwell |first=Richard |date=15 September 2016 |title=Hinkley Point nuclear energy plant approved – but still doubts over Sizewell C as new controls on foreign investment agreed |work=Ipswich Star |url=http://www.ipswichstar.co.uk/news/hinkley_point_nuclear_energy_plant_approved_but_still_doubts_over_sizewell_c_as_new_controls_on_foreign_investment_agreed_1_4697063 |access-date=27 October 2016}}

In May 2020, the {{abbr|NGO|non-governmental organization}} Energy for Humanity issued an open letter calling for the Department of Business, Energy and Industrial Strategy to support the project as without nuclear the "action on climate will be more difficult, more expensive, and more likely to fail". It also called for lessons to be drawn from Hinkley Point C as well as the UK's offshore wind programme to ensure a timely procurement schedule.{{Cite web |date=27 May 2020 |title=Open letter to Secretary of State for Business, Energy and Industrial Strategy |url=https://energyforhumanity.org/en/nuclear/open-letter-to-secretary-of-state-for-business-energy-and-industrial-strategy/ |access-date=27 May 2020 |website=Energy For Humanity |language=en-GB}}

Concerns have been expressed regarding one of the shareholders in the consortium,{{Cite news |last=Wood |first=Vincent |date=October 25, 2018 |title=Spy warning on Chinese nuclear company |work=The Times |url=https://www.thetimes.com/article/spy-warning-on-chinese-nuclear-company-cgn-china-general-nuclear-trrh0hftv |url-access=subscription}}{{Cite news |last=Pagnamenta |first=Robin |date=24 January 2019 |title=Britain's nuclear industry is falling inexorably into Chinese hands |work=The Daily Telegraph |url=https://www.telegraph.co.uk/technology/2019/01/24/britains-nuclear-industry-falling-inexorably-chinese-hands/ |url-access=subscription}}

China General Nuclear Power Group. CGN is owned by the Chinese government and has been blacklisted by the US Department of Commerce for attempting to acquire advanced US nuclear technology and material for diversion to military use.{{Cite news |last=Ng |first=Eric |date=11 August 2016 |title=China General Nuclear Power accused of espionage with its adviser in the US |work=South China Morning Post |url=https://www.scmp.com/business/companies/article/2002539/china-general-nuclear-power-accused-espionage-its-adviser-us}}{{Cite web |last1=Teplinsky |first1=Elina |last2=Leidich |first2=Anne |last3=Hutman |first3=Aaron R. |date=August 15, 2019 |title=Four China Nuclear Industry Companies Added to "Entity List" |url=https://www.pillsburylaw.com/en/news-and-insights/china-industry-entity-list.html |website=Pillsbury Insights |publisher=Pillsbury Winthrop Shaw Pittman}}

EDF submitted its planning application in May 2020, declaring 25,000 job opportunities and 70% of investment being spent in UK. The plant will largely replicate Hinkley Point C design to reuse experience, lower cost and ensure high levels of safety.{{Cite web |date=27 May 2020 |title=Sizewell C submits planning application |url=https://namrc.co.uk/industry/sizewell-c-planning-application/ |access-date=27 May 2020 |website=Nuclear AMRC |language=en-GB}} The proposal was welcomed by Unite the Union.{{Cite web |date=28 May 2020 |title=25,000 jobs to build new Suffolk nuclear power station a boost for post-pandemic economy, says Unite |url=https://unitetheunion.org/news-events/news/2020/may/25-000-jobs-to-build-new-suffolk-nuclear-power-station-a-boost-for-post-pandemic-economy-says-unite/ |access-date=28 May 2020 |website=Unite the Union |language=en}}

On 27 May 2020, EDF Energy announced that it had submitted a development consent order application.{{Cite web |date=27 May 2020 |title=Sizewell C submits planning application |url=https://www.edfenergy.com/media-centre/news-releases/sizewell-c-dco |access-date=2 June 2020 |publisher=EDF Energy}} However EDF have yet to organise financing, and cannot take on more construction risk in the UK. EDF is looking to the UK government to assist on financing either by offering a regulated asset base (RAB) model used on less risky infrastructure, though that puts an immediate cost burden on end consumers or through other approaches such as a government equity stake in the development.{{Cite news |last1=Thomas |first1=Nathalie |last2=Pickard |first2=Jim |date=2 June 2020 |title=Plan for new UK nuclear plant under intense scrutiny |work=Financial Times |url=https://www.ft.com/content/4e3221ef-ac1e-43cc-8d68-e1397ca0637f |url-access=subscription |access-date=4 June 2020}}

On 30 June 2020, EDF Energy announced that it had applied to the Office for Nuclear Regulation (ONR) for a licence to build and operate Sizewell C. The ONR is responsible for the safe operation of nuclear sites in the UK and for permitting new nuclear site licences{{snd}}one of the key regulatory requirements for building and operating a new power station.{{Cite web |date=June 30, 2020 |title=Sizewell C applies for a licence to build and operate in Suffolk |url=https://www.edfenergy.com/energy/nuclear-new-build-projects/sizewell-c/news-views/sizewell-c-applies-licence-build-and-operate-in-suffolk |access-date=8 July 2020 |publisher=EDF Energy}}

In March 2022, it was announced that the UK government and EDF would each take a 20% stake in the project, with infrastructure investors and pension funds expected to take up the remaining 60%.{{cite news |title=Sizewell C nuclear power station: Government to take 20% stake |url=https://www.bbc.com/news/business-60889001 |work=BBC News |date=27 March 2022}}

{{Portal|England|Energy|Nuclear technology}}

• Nuclear power in the United Kingdom
• Energy policy of the United Kingdom
• Energy in the United Kingdom
• List of nuclear reactors#United Kingdom
• Hilda Murrell
• Proposed nuclear power stations in the United Kingdom

{{Reflist}}

• {{Cite journal |last=Wall |first=Christine |date=2019 |title='Nuclear prospects': the siting and construction of Sizewell A power station 1957–1966 |url=https://www.tandfonline.com/doi/full/10.1080/13619462.2018.1519424 |journal=Contemporary British History |volume=33 |issue=2 |pages=246–273|doi=10.1080/13619462.2018.1519424 |s2cid=150174829 }}
• {{Cite news |title=Gallery: Sizewell B |work=BBC Suffolk |url=http://www.bbc.co.uk/suffolk/content/image_galleries/sizewell_b_tour_gallery.shtml}}
• {{Cite news |last=Kettlewell |first=Julianna |date=6 October 2005 |title=In pictures: Living with Sizewell B |work=BBC News |url=http://news.bbc.co.uk/1/shared/spl/hi/pop_ups/05/sci_nat_living_with_sizewell_b/html/1.stm}}
• {{Cite news |title=Sizewell B given 10 more years |work=BBC News |url=http://news.bbc.co.uk/1/hi/england/suffolk/4316424.stm}}

{{Commons category}}

• [https://web.archive.org/web/20111002215941/http://www.magnoxsites.co.uk/our-sites/sizewell-a Magnox Limited, Sizewell A]
• [http://www.edfenergy.com/about-us/energy-generation/nuclear-generation/nuclear-power-stations/sizewell-b.shtml EDF Energy – Sizewell B]
• International Atomic Energy Agency power station performance data: [https://web.archive.org/web/20110604093043/http://www.iaea.org/cgi-bin/db.page.pl/pris.ophis.htm?country=GB&site=SIZEWELL%20A&refno=10A&opyear=2020 Sizewell A1], [https://web.archive.org/web/20110604093111/http://www.iaea.org/cgi-bin/db.page.pl/pris.ophis.htm?country=GB&site=SIZEWELL%20A&&refno=10B&opyear=2020 Sizewell A2], [https://web.archive.org/web/20110604093119/http://www.iaea.org/cgi-bin/db.page.pl/pris.ophis.htm?country=GB&site=SIZEWELL%20B&refno=24&opyear=2020 Sizewell B]
• [http://econtent.unm.edu/cdm4/item_viewer.php?CISOROOT=/nuceng&CISOPTR=95&CISOBOX=1&REC=1 Sizewell B], Nuclear Engineering International wall chart, December 1982

{{East of England powerstations}}

{{Nuclear power in the United Kingdom}}

{{Authority control}}

Category:Buildings and structures in Suffolk

Category:Power stations in the East of England

Category:Nuclear power stations in England

Category:Électricité de France

Category:Nuclear power stations with proposed reactors

Category:Leiston