Nuclear Power / Nuclear Energy / Nuclear Risk: How does a pressurized water reactor work?

Veröffentlicht am 19.10.2007 in der Kategorie English Section von Axel Mayer


Nuclear Power / Nuclear Energy / Nuclear Risk: How does a pressurized water reactor work?

Many nuclear power plants operate with pressurized water reactors (PWRs). The PWR is the most common reactor type. Nuclear fission of the fuel elements heats up the water in the reactor to approximately 315°C (600°F). The water is constantly kept under pressure (about 2200 psig [15 Mpa]). To control or shut down a nuclear reactor, control rods are used. When a control rod is inserted in the reactor core, it absorbs a part of the neutrons released by the nuclear fission events. Thus, the neutrons are not available to trigger off further nuclear fissions. In this way uncontrolled increase of chain-reactions in the reactor is prevented. The 315°C warm water by means of a heat exchanger (here called steam generator) heats up the secondary coolant loop. In the secondary coolant loop the steam generator forms steam which drives the turbine.

Every nuclear power plant
(PWRs as well) in one year´s operating time produces the radioactivity of a hiroshima bomb per megawatt of electric power. This means that in a nuclear power plant with an annual power of 1200 MW the radioactivity of approximately 1200 hiroshima bombs comes into existence. Certain parts of the radioactive material decay very quickly. Others, however, have half-lives longer than 24,000 years (e.g. plutonium) and therefore will factually exist permanently. Ageing nuclear power plants with extended operating times and embrittled reactor vessels heighten the risk of an accident.

This type of reactor is not technically safe, as could be seen from the nuclear meltdown in the almost new PWR in 1979 in Harrisburg, U.S. (Three Mile Island accident). In case of an accident or a terrorist attack the nuclear power plant is shut down by means of the control rods. However, for a period of several days after the shutdown the radioactive decay of the fission products continues to generate heat.

All nuclear power plants
are provided with redundant emergency cooling systems to safely remove the decay heat also in the event of a disaster. When the cooling systems break down (as it occurred during the Three Mile Island accident), the rising temperature can cause a nuclear meltdown.
If the fuel assemblies in the core melt, the rate of chain reactions will increase and lead to an extreme and uncontrolled heating-up process. When the reactor vessel does not resist or when a huge amount of radiation emerges, the accident is called 'maximum credible accident' [Super-GAU].

PWR – Not safe from terrorist attacks and plane crashes

The Oekoinstitut [ecological institute] Darmstadt has calculated the areal impact of a disaster of the kind described above, using the PWR of the French nuclear power plant Fessenheim as an example. The study was based on an assumed major accident in the French EDF/EnBW- nuclear power plant Fessenheim:

In case of south-west wind and rain, the area of damage would have a spread of up to 370 km from Fessenheim to the region of Würzburg-Nürnberg. If the Chernobyl guidelines were adopted, in this zone all inhabitants would have to be evacuated for a period of 50 years.

Klaus Traube
(nuclear expert; former director of AEG´s nuclear reactor department at General Dynamics, San Diego; after this, head of Interatom) wrote:

The analysis of numerous hazardous incidents shows that they usually are triggered off by an unexpected concurrence of malfunctions and operating errors (like for example in the Harrisburg/Three Mile Island accident and, by the way, in Chernobyl as well). Individually, the malfunctions and errors seem to be trivial. Elaborate risk studies dealing with the possibilities and probabilities of a nuclear reactor´s disastrous breakdown arrive at the same conclusion. They confirm: Every running reactor at any time renders possible accidents leading to nuclear meltdowns with a subsequent disastrous release of radioactivity. Not the truth of this statement, but solely the probability of occurrence is debated among experts. Furthermore, it is a fact that acts of terrorism (like for example plane crashes) can cause a nuclear disaster. Again, solely the probability is debatable.

Axel Mayer

Climate Change, Nuclear Energy and Fukushima...

Saving the Climate with Nuclear Energy?
The nuclear power industry and its governmental allies are spending tens of millions of dollars annually to promote atomic power as an “emissions-free” energy source. Their goal is to encourage the construction of new nuclear reactors in the U.S. in France, England and worldwide and prevent the shutdown of dangerous old reactors (Fessenheim, Beznau, Mühleberg....) that cannot compete economically with clean energy sources like wind and solar power..

Yet nuclear power is not only ineffective at addressing climate change, when the entire fuel chain is examined, nuclear power is a net producer of greenhouse gases. Adding enough nuclear power to make a meaningful reduction in greenhouse gas emissions would cost trillions of dollars, create tens of thousands of tons of lethal high-level radioactive waste, contribute to further proliferation of nuclear weapons materials, result in a Chernobyl or Fukushima-scale accident once every decade or so, and, perhaps most significantly, squander the resources necessary to implement meaningful climate change policies.
Source of this section and where to go for up-to-date information on nuclear power and climate.

Danger: Nuclear Reactors worldwide / Nuclear Power / Nuclear Energy / Nuclear Risk (18.10.07)

(World Nuclear Association)

Almaraz-1, Spain, PWR
Almaraz-2, Spain, PWR
Angra-1, Brazil, PWR
Angra-2, Brazil, PWR
Arkansas Nuclear One-1, United States, PWR
Arkansas Nuclear One-2, United States, PWR
Armenia-2 (Metsamor), Armenia, PWR/VVER
Asco-1, Spain, PWR
Asco-2, Spain, PWR
Atucha-1, Argentina, PHWR
Balakovo-1, Russian Federation, PWR/VVER
Balakovo-2, Russian Federation, PWR/VVER
Balakovo-3, Russian Federation, PWR/VVER
Balakovo-4, Russian Federation, PWR/VVER
Beaver Valley-1, United States, PWR
Beaver Valley-2, United States, PWR
Belleville-1, France, PWR
Belleville-2, France, PWR
Beloyarsk-3 (BN-600), Russian Federation, FBR
Beznau-1, Switzerland, PWR
Beznau-2, Switzerland, PWR
Biblis-A, Germany, PWR
Biblis-B, Germany, PWR
Bilibino unit A, Russian Federation, LWGR/EGP
Bilibino unit B, Russian Federation, LWGR/EGP
Bilibino unit C, Russian Federation, LWGR/EGP
Bilibino unit D, Russian Federation, LWGR/EGP
Blayais-1, France, PWR
Blayais-2, France, PWR
Blayais-3, France, PWR
Blayais-4, France, PWR
Bohunice-1, Slovak Republic, PWR/VVER
Bohunice-2, Slovak Republic, PWR/VVER
Bohunice-3, Slovak Republic, PWR/VVER
Bohunice-4, Slovak Republic, PWR/VVER
Borssele, Netherlands, PWR
Braidwood-1, United States, PWR
Braidwood-2, United States, PWR
Brokdorf, Germany, PWR
Browns Ferry-2, United States, BWR
Browns Ferry-3, United States, BWR
Bruce-3, Canada, PHWR/CANDU
Bruce-4, Canada, PHWR/CANDU
Bruce-5, Canada, PHWR/CANDU
Bruce-6, Canada, PHWR/CANDU
Bruce-7, Canada, PHWR/CANDU
Bruce-8, Canada, PHWR/CANDU
Brunsbuttel, Germany, BWR
Brunswick-1, United States, BWR
Brunswick-2, United States, BWR
Bugey-2, France, PWR
Bugey-3, France, PWR
Bugey-4, France, PWR
Bugey-5, France, PWR
Byron-1, United States, PWR
Byron-2, United States, PWR
Callaway-1, United States, PWR
Calvert Cliffs-1, United States, PWR
Calvert Cliffs-2, United States, PWR
Catawba-1, United States, PWR
Catawba-2, United States, PWR
Cattenom-1, France, PWR
Cattenom-2, France, PWR
Cattenom-3, France, PWR
Cattenom-4, France, PWR
Cernavoda-1, Romania, PHWR/CANDU
Chasnupp-1, Pakistan, PWR
Chin Shan-1, Taiwan, BWR
Chin Shan-2, Taiwan, BWR
Chinon-B1, France, PWR
Chinon-B2, France, PWR
Chinon-B3, France, PWR
Chinon-B4, France, PWR
Chooz-B1, France, PWR
Chooz-B2, France, PWR
Civaux-1, France, PWR
Civaux-2, France, PWR
Clinton-1, United States, BWR
Cofrentes, Spain, BWR
Columbia (WNP-2), United States, BWR
Comanche Peak-1, United States, PWR
Comanche Peak-2, United States, PWR
Cooper, United States, BWR
Cruas-1, France, PWR
Cruas-2, France, PWR
Cruas-3, France, PWR
Cruas-4, France, PWR
Crystal River-3, United States, PWR
Dampierre-1, France, PWR
Dampierre-2, France, PWR
Dampierre-3, France, PWR
Dampierre-4, France, PWR
Darlington-1, Canada, PHWR/CANDU
Darlington-2, Canada, PHWR/CANDU
Darlington-3, Canada, PHWR/CANDU
Darlington-4, Canada, PHWR/CANDU
Davis Besse-1, United States, PWR
Diablo Canyon-1, United States, PWR
Diablo Canyon-2, United States, PWR
Doel-1, Belgium, PWR
Doel-2, Belgium, PWR
Doel-3, Belgium, PWR
Doel-4, Belgium, PWR
Donald Cook-1, United States, PWR
Donald Cook-2, United States, PWR
Dresden-2, United States, BWR
Dresden-3, United States, BWR
Duane Arnold-1, United States, BWR
Dukovany-1, Czech Republic, PWR/VVER
Dukovany-2, Czech Republic, PWR/VVER
Dukovany-3, Czech Republic, PWR/VVER
Dukovany-4, Czech Republic, PWR/VVER
Dungeness-A1, United Kingdom, GCR (Magnox)
Dungeness-A2, United Kingdom, GCR (Magnox)
Dungeness-B1, United Kingdom, AGR
Dungeness-B2, United Kingdom, AGR
Embalse, Argentina, PHWR
Emsland, Germany, PWR
Enrico Fermi-2, United States, BWR
Farley-1, United States, PWR
Farley-2, United States, PWR
Fessenheim-1, France, PWR
Fessenheim-2, France, PWR
Fitzpatrick, United States, BWR
Flamanville-1, France, PWR
Flamanville-2, France, PWR
Forsmark-1, Sweden, BWR
Forsmark-2, Sweden, BWR
Forsmark-3, Sweden, BWR
Fort Calhoun-1, United States, PWR
Fukushima-Daiichi-1, Japan, BWR
Fukushima-Daiichi-2, Japan, BWR
Fukushima-Daiichi-3, Japan, BWR
Fukushima-Daiichi-4, Japan, BWR
Fukushima-Daiichi-5, Japan, BWR
Fukushima-Daiichi-6, Japan, BWR
Fukushima-Daini-1, Japan, BWR
Fukushima-Daini-2, Japan, BWR
Fukushima-Daini-3, Japan, BWR
Fukushima-Daini-4, Japan, BWR
Genkai-1, Japan, PWR
Genkai-2, Japan, PWR
Genkai-3, Japan, PWR
Genkai-4, Japan, PWR
Gentilly-2, Canada, PHWR/CANDU
Goesgen, Switzerland, PWR
Golfech-1, France, PWR
Golfech-2, France, PWR
Grafenrheinfeld, Germany, PWR
Grand Gulf-1, United States, BWR
Gravelines-1, France, PWR
Gravelines-2, France, PWR
Gravelines-3, France, PWR
Gravelines-4, France, PWR
Gravelines-5, France, PWR
Gravelines-6, France, PWR
Grohnde, Germany, PWR
Guangdong-1 (Daya Bay 1), China, mainland, PWR
Guangdong-2 (Daya Bay 2), China, mainland, PWR
Gundremmingen-B, Germany, BWR
Gundremmingen-C, Germany, BWR
H B Robinson-2, United States, PWR
Hamaoka-1, Japan, BWR
Hamaoka-2, Japan, BWR
Hamaoka-3, Japan, BWR
Hamaoka-4, Japan, BWR
Hamaoka-5, Japan, ABWR
Hartlepool-1, United Kingdom, AGR
Hartlepool-2, United Kingdom, AGR
Hatch-1, United States, BWR
Hatch-2, United States, BWR
Heysham-A1, United Kingdom, AGR
Heysham-A2, United Kingdom, AGR
Heysham-B1, United Kingdom, AGR
Heysham-B2, United Kingdom, AGR
Hinkley Point-B1, United Kingdom, AGR
Hinkley Point-B2, United Kingdom, AGR
Hope Creek-1, United States, BWR
Hunterston-B1, United Kingdom, AGR
Hunterston-B2, United Kingdom, AGR
Ignalina-2, Lithuania, LWGR/RBMK
Ikata-1, Japan, PWR
Ikata-2, Japan, PWR
Ikata-3, Japan, PWR
Indian Point-2, United States, PWR
Indian Point-3, United States, PWR
Isar-1, Germany, BWR
Isar-2, Germany, PWR
Jose Cabrera-1 (Zorita), Spain, PWR
Kaiga-1, India, PHWR
Kaiga-2, India, PHWR
Kakrapar-1, India, PHWR
Kakrapar-2, India, PHWR
Kalinin-1, Russian Federation, PWR/VVER
Kalinin-2, Russian Federation, PWR/VVER
Kalinin-3, Russian Federation, PWR/VVER
Kanupp, Pakistan, PHWR
Kashiwazaki Kariwa-1, Japan, BWR
Kashiwazaki Kariwa-2, Japan, BWR
Kashiwazaki Kariwa-3, Japan, BWR
Kashiwazaki Kariwa-4, Japan, BWR
Kashiwazaki Kariwa-5, Japan, BWR
Kashiwazaki Kariwa-6, Japan, ABWR
Kashiwazaki Kariwa-7, Japan, ABWR
Khmelnitski-1, Ukraine, PWR/VVER
Khmelnitski-2, Ukraine, PWR/VVER
Koeberg-1, South Africa, PWR
Koeberg-2, South Africa, PWR
Kola-1, Russian Federation, PWR/VVER
Kola-2, Russian Federation, PWR/VVER
Kola-3, Russian Federation, PWR/VVER
Kola-4, Russian Federation, PWR/VVER
Kori-1, Korea RO (South), PWR
Kori-2, Korea RO (South), PWR
Kori-3, Korea RO (South), PWR
Kori-4, Korea RO (South), PWR
Kozloduy-3, Bulgaria, PWR/VVER
Kozloduy-4, Bulgaria, PWR/VVER
Kozloduy-5, Bulgaria, PWR/VVER
Kozloduy-6, Bulgaria, PWR/VVER
Krsko, Slovenia, PWR
Krummel, Germany, BWR
Kuosheng-1, Taiwan, BWR
Kuosheng-2, Taiwan, BWR
Kursk-1, Russian Federation, LWGR/RBMK
Kursk-2, Russian Federation, LWGR/RBMK
Kursk-3, Russian Federation, LWGR/RBMK
Kursk-4, Russian Federation, LWGR/RBMK
Laguna Verde-1, Mexico, BWR
Laguna Verde-2, Mexico, BWR
LaSalle-1, United States, BWR
LaSalle-2, United States, BWR
Leibstadt, Switzerland, BWR
Leningrad-1, Russian Federation, LWGR/RBMK
Leningrad-2, Russian Federation, LWGR/RBMK
Leningrad-3, Russian Federation, LWGR/RBMK
Leningrad-4, Russian Federation, LWGR/RBMK
Limerick-1, United States, BWR
Limerick-2, United States, BWR
Lingao-1, China, mainland, PWR
Lingao-2, China, mainland, PWR
Loviisa-1, Finland, PWR/VVER
Loviisa-2, Finland, PWR/VVER
Maanshan-1, Taiwan, PWR
Maanshan-2, Taiwan, PWR
Madras-1, India, PHWR
Madras-2, India, PHWR
McGuire-1, United States, PWR
McGuire-2, United States, PWR
Mihama-1, Japan, PWR
Mihama-2, Japan, PWR
Mihama-3, Japan, PWR
Millstone-2, United States, PWR
Millstone-3, United States, PWR
Mochovce-1, Slovak Republic, PWR/VVER
Mochovce-2, Slovak Republic, PWR/VVER
Monticello, United States, BWR
Muehleberg, Switzerland, BWR
Narora-1, India, PHWR
Narora-2, India, PHWR
Neckarwestheim-1, Germany, PWR
Neckarwestheim-2, Germany, PWR
Nine Mile Point-1, United States, BWR
Nine Mile Point-2, United States, BWR
Nogent-1, France, PWR
Nogent-2, France, PWR
North Anna-1, United States, PWR
North Anna-2, United States, PWR
Novovoronezh-3, Russian Federation, PWR/VVER
Novovoronezh-4, Russian Federation, PWR/VVER
Novovoronezh-5, Russian Federation, PWR/VVER
Oconee-1, United States, PWR
Oconee-2, United States, PWR
Oconee-3, United States, PWR
Ohi-1, Japan, PWR
Ohi-2, Japan, PWR
Ohi-3, Japan, PWR
Ohi-4, Japan, PWR
Oldbury-1, United Kingdom, GCR (Magnox)
Oldbury-2, United Kingdom, GCR (Magnox)
Olkiluoto-1, Finland, BWR
Olkiluoto-2, Finland, BWR
Onagawa-1, Japan, BWR
Onagawa-2, Japan, BWR
Onagawa-3, Japan, BWR
Oskarshamn-1, Sweden, BWR
Oskarshamn-2, Sweden, BWR
Oskarshamn-3, Sweden, BWR
Oyster Creek, United States, BWR
Paks-1, Hungary, PWR
Paks-2, Hungary, PWR
Paks-3, Hungary, PWR
Paks-4, Hungary, PWR
Palisades, United States, PWR
Palo Verde-1, United States, PWR
Palo Verde-2, United States, PWR
Palo Verde-3, United States, PWR
Paluel-1, France, PWR
Paluel-2, France, PWR
Paluel-3, France, PWR
Paluel-4, France, PWR
Peach Bottom-2, United States, BWR
Peach Bottom-3, United States, BWR
Penly-1, France, PWR
Penly-2, France, PWR
Perry-1, United States, BWR
Phenix, France, FBR
Philippsburg-1, Germany, BWR
Philippsburg-2, Germany, PWR
Pickering-1, Canada, PHWR/CANDU
Pickering-4, Canada, PHWR/CANDU
Pickering-5, Canada, PHWR/CANDU
Pickering-6, Canada, PHWR/CANDU
Pickering-7, Canada, PHWR/CANDU
Pickering-8, Canada, PHWR/CANDU
Pilgrim-1, United States, BWR
Point Beach-1, United States, PWR
Point Beach-2, United States, PWR
Point Lepreau, Canada, PHWR/CANDU
Prairie Island-1, United States, PWR
Prairie Island-2, United States, PWR
Qinshan-1, China, mainland, PWR
Qinshan-2, China, mainland, PWR
Qinshan-3, China, mainland, PWR
Qinshan-4, China, mainland, PHWR/CANDU
Qinshan-5, China, mainland, PHWR/CANDU
Quad Cities-1, United States, BWR
Quad Cities-2, United States, BWR
R E Ginna, United States, PWR
Rajasthan-1, India, PHWR
Rajasthan-2, India, PHWR
Rajasthan-3, India, PHWR
Rajasthan-4, India, PHWR
Ringhals-1, Sweden, BWR
Ringhals-2, Sweden, PWR
Ringhals-3, Sweden, PWR
Ringhals-4, Sweden, PWR
River Bend-1, United States, BWR
Rovno-1, Ukraine, PWR/VVER
Rovno-2, Ukraine, PWR/VVER
Rovno-3, Ukraine, PWR/VVER
Rovno-4, Ukraine, PWR/VVER
Salem-1, United States, PWR
Salem-2, United States, PWR
San Onofre-2, United States, PWR
San Onofre-3, United States, PWR
Santa Maria de Garona, Spain, BWR
Seabrook-1, United States, PWR
Sendai-1, Japan, PWR
Sendai-2, Japan, PWR
Sequoyah-1, United States, PWR
Sequoyah-2, United States, PWR
Shearon Harris-1, United States, PWR
Shika-1, Japan, BWR
Shimane-1, Japan, BWR
Shimane-2, Japan, BWR
Sizewell-A1, United Kingdom, GCR (Magnox)
Sizewell-A2, United Kingdom, GCR (Magnox)
Sizewell-B, United Kingdom, PWR
Smolensk-1, Russian Federation, LWGR/RBMK
Smolensk-2, Russian Federation, LWGR/RBMK
Smolensk-3, Russian Federation, LWGR/RBMK
South Texas-1, United States, PWR
South Texas-2, United States, PWR
South Ukraine-1, Ukraine, PWR/VVER
South Ukraine-2, Ukraine, PWR/VVER
South Ukraine-3, Ukraine, PWR/VVER
St. Alban-1, France, PWR
St. Alban-2, France, PWR
St. Laurent-B1, France, PWR
St. Laurent-B2, France, PWR
St. Lucie-1, United States, PWR
St. Lucie-2, United States, PWR
Surry-1, United States, PWR
Surry-2, United States, PWR
Susquehanna-1, United States, BWR
Susquehanna-2, United States, BWR
Takahama-1, Japan, PWR
Takahama-2, Japan, PWR
Takahama-3, Japan, PWR
Takahama-4, Japan, PWR
Tarapur-1, India, BWR
Tarapur-2, India, BWR
Tarapur-4, India, PHWR
Temelin-1, Czech Republic, PWR/VVER
Temelin-2, Czech Republic, PWR/VVER
Three Mile Island-1, United States, PWR
Tianwan-1, China, mainland, PWR/VVER
Tihange-1, Belgium, PWR
Tihange-2, Belgium, PWR
Tihange-3, Belgium, PWR
Tokai-2, Japan, BWR
Tomari-1, Japan, PWR
Tomari-2, Japan, PWR
Torness unit A, United Kingdom, AGR
Torness unit B, United Kingdom, AGR
Tricastin-1, France, PWR
Tricastin-2, France, PWR
Tricastin-3, France, PWR
Tricastin-4, France, PWR
Trillo-1, Spain, PWR
Tsuruga-1, Japan, BWR
Tsuruga-2, Japan, PWR
Turkey Point-3, United States, PWR
Turkey Point-4, United States, PWR
Ulchin-1, Korea RO (South), PWR
Ulchin-2, Korea RO (South), PWR
Ulchin-3, Korea RO (South), PWR
Ulchin-4, Korea RO (South), PWR
Ulchin-5, Korea RO (South), PWR
Unterweser, Germany, PWR
Vandellos-2, Spain, PWR
Vermont Yankee, United States, BWR
Virgil C Summer-1, United States, PWR
Vogtle-1, United States, PWR
Vogtle-2, United States, PWR
Volgodonsk-1 (Rostov), Russian Federation, PWR/VVER
Waterford-3, United States, PWR
Watts Bar-1, United States, PWR
Wolf Creek, United States, PWR
Wolsong-1, Korea RO (South), PHWR
Wolsong-2, Korea RO (South), PHWR
Wolsong-3, Korea RO (South), PHWR
Wolsong-4, Korea RO (South), PHWR
Wylfa-1, United Kingdom, GCR (Magnox)
Wylfa-2, United Kingdom, GCR (Magnox)
Yonggwang-1, Korea RO (South), PWR
Yonggwang-2, Korea RO (South), PWR
Yonggwang-3, Korea RO (South), PWR
Yonggwang-4, Korea RO (South), PWR
Yonggwang-5, Korea RO (South), PWR
Yonggwang-6, Korea RO (South), PWR
Zaporozhe-1, Ukraine, PWR/VVER
Zaporozhe-2, Ukraine, PWR/VVER
Zaporozhe-3, Ukraine, PWR/VVER
Zaporozhe-4, Ukraine, PWR/VVER
Zaporozhe-5, Ukraine, PWR/VVER
Zaporozhe-6, Ukraine, PWR/VVER

Nuclear Power / Nuclear Energy / Nuclear Risk


PWR = Pressurized Water Reactors
BWR = Boiling Water Reactors
CANDU = Pressurized Heavy Water Reactor
AGR = Advanced Gas-cooled Reactor
VVER = Vodo-Vodyanoi Energetichesky Reactor
PHWR = Pressurised Heavy Water Reactor
LWGR = grahite moderated light water cooled
RBMK = Reaktor Bolshoy Moshchnosti Kanalniy
ABWR = Advanced Boiling Water Reactor
EGP = graphite channel power reactor with steam overheat
FBR = Fast Breeder Reactor
GCR (Magnox) = Gas Cooled Reactor