Dungeness Nuclear Pouer Station

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Dungeness A Nuclear Power Station
Dungeness A
LocationKent, South East England
Coordinates50°54′50″N 0°57′50″E / 50.913889°N 0.963889°E / 50.913889; 0.963889Coordinates: 50°54′50″N 0°57′50″E / 50.913889°N 0.963889°E / 50.913889; 0.963889
Commission date1965
Decommission date2006
Awner(s)Nuclear Decommissioning Authority
Operator(s)Magnox Ltd
Pouer generation
Units decommissioned2 X 219 MWe net
Nameplate capacity500 MWe
grid reference TR0832016959
Dungeness B Nuclear Power Station
Dungeness B
LocationKent, South East England
Coordinates50°54′50″N 0°57′50″E / 50.913889°N 0.963889°E / 50.913889; 0.963889
Construction began1965
Commission date1983
Decommission dateExpected 2028
Operator(s)EDF Energy
Pouer generation
Units operational2 x 600 MWe (Operating at ~545 MWe net[1] )
Nameplate capacity1090 MWe
grid reference TR0832016959

Dungeness nuclear pouer station may refer tae either one or both o a pair o nuclear pouer stations, only one o which is still operational, locatit on the Dungeness headland in the sooth o Kent, Ingland.

Dungeness A[eedit | eedit soorce]

Dungeness A is a legacy Magnox pouer station that was connected tae the National Grid in 1965 an has reached the end o its life. It possessed two nuclear reactors producing 219 MW o electricity each, wi a total capacity o 438 MW. The construction was undertaken bi a consortium known as the Nuclear Power Group ('TNPG'). The reactors were supplied bi TNPG an the turbines bi C. A. Parsons & Co.

Dungeness B[eedit | eedit soorce]

Dungeness B is an Advanced Gas-cuiled Reactor (AGR) power station consistin o two 615 MW reactors, which began operation in 1983 an 1985 respectively. Dungeness B was the first commercial scale AGR power station tae be constructed. Its design was based on the much smaller Windscale AGR prototype: the WAGR. The £89 million contract was awarded in August 1965 tae Atomic Power Construction ('APC'),[2] a consortium backed by Crompton Parkinson, Fairey Aviation Company, International Combustion an Richardsons Westgarth & Company. The completion date was set as 1970.

During construction, many problems were encountered in scaling up the WAGR design. Problems wi the construction o the pressure vessel liner had distorted it, so that the boilers, which were tae fit in an annular space atween the reactor an the pressure vessel, could not be installed, an the liner had tae be partially dismantled an rebuilt. This work only cost aboot £200,000, but there was a huge cost o financing, for an extra 18 unproductive months, a pouer station costin around £100 million, o which some 60% was already on the ground.[3] Serious problems were also discovered wi the design o the boilers, which had tae withstand the poundin o hot caurbon dioxide (CO2), pressurised tae 600 punds per square inch (4.1 megapascals) an pumped around the reactor coolant circuit bi massive gas circulators, an the casings, hangers an tube supports all had tae be redesigned. The cost o these modifications, an financin durin the delays, caused severe financial pressures for the consortium an its backers, an in 1969 APC collapsed in tae administration.

The Central Electricity Generating Board took over project management, imposed light penalties in order not tae cripple Fairey an International Combustion, an appointed British Nuclear Design and Construction (BNDC) as main contractor. In 1971, problems wi corrosion o mild steel components in the first generation Magnox reactors gave the designers cause for concern. The Dungeness B restraint couplings - mechanical linkages that held the graphite core in place whilst allowing it tae expand and contract in response tae temperature chynges - were made o mild steel an could be subject tae the same corrosion. It was decided tae replace them wi components made from a new material.[4] In 1972, problems were found wi the galvanised wire that was used tae attach thermocouples tae stainless steel boiler tubes. Durin heat treatment o the tubes at temperatures up tae 1,050 °C, the galvanising zinc diffused in tae the tubes an made them brittle. The cost had by then risen tae £170 million.[5] By 1975, the CEGB was reportin that the power station would not be completit until 1977 an that its cost had risen tae £280 million.[6] By 1979 the cost had risen further tae £410 million.[7] Reactor 1 first generated pouer on 3 April 1983, some 13 years behind schedule an at a cost o £685 million, four times the initial estimate in inflation-adjusted terms.[8]

Like the "A" station, its turbines were built bi C.A. Parsons & Company an it has two 600 MWe turbo-alternator sets, producin a maximum output o 1200 MWe, though net output is 1090 MWe after the effects o house load, an downrating the reactor output due tae corrosion an vibration concerns.[9]

In March 2009 Unit B21 was brocht doon for maintenance. Serious problems were found an the reactor was shut doon for almost 18 month.[10] On 24 November 2009 a small fire in the boiler annexe o Unit B22 caused the second reactor also tae be shut doon. Subsequently Unit B22 has been intermittently shut doon for up tae several months at a time. Unit B21 was restarted in August 2010.[11] Unplanned shutdowns continued into 2011,[12][13] with B21 down for repairs from November 2011 to March 2012.[14]

In 2005 the station's accountin closure date was 2018, 35 years after first pouer generation.[15] In 2015 the plant was gien a ten-year life extension, wi an upgrade tae control room computer systems an improved flood defences, takin the accountin closure date to 2028.[16]

References[eedit | eedit soorce]

  1. "Dungeness B EDF Energy". Retrieved 28 Apryle 2014.
  2. "Events - World Nuclear Association". www.world-nuclear.org.
  3. The Times, Tuesday, 10 December 1968; pg. 24; Issue 57430; col A
  4. The Times, Thursday, 11 March 1971; pg. 19; Issue 58119; col E
  5. The Times, Saturday, 4 November 1972; pg. 19; Issue 58623; col C
  6. The Times, Thursday, 6 November 1975; pg. 20; Issue 59546; col A
  7. The Times, Wednesday, 23 January 1980; pg. 3; Issue 60531; col E
  8. Walter C. Patterson (1985). Going Critical: An Unofficial History of British Nuclear Power (PDF). Paladin. ISBN 0-586-08516-5. Retrieved 12 Juin 2009.
  9. British Energy: Dungeness B Archived 1 Mey 2006 at the Wayback Machine
  10. "Dungeness B reactor back up after repairs". 21 August 2010.
  11. "Fire shuts nuclear power station". BBC. 24 November 2009. Retrieved 24 November 2009.
  12. "UPDATE 1-UK Hunterston B7 nuclear unit restarts Fri". Reuters. 5 Mairch 2011. Archived frae the original on 30 Julie 2018. Retrieved 11 Juin 2018.
  13. "UK Dungeness B22 unit back on grid since Jul 24-EDF". Reuters. 1 August 2011. Archived frae the original on 30 Julie 2018. Retrieved 11 Juin 2018.
  14. "ABLE-UK nuclear power plant outages". Reuters. 25 November 2011. Archived frae the original on 19 November 2015. Retrieved 11 Juin 2018.
  15. 10-year life extension at Dungeness B nuclear power station, British Energy, 15 September 2005, archived frae the original on 22 Mairch 2006, retrieved 19 Juin 2008
  16. "UK nuclear plant gets ten-year extension". World Nuclear News. 20 Januar 2015. Retrieved 21 Januar 2015.