Neckarwestheim Nuclear Power Plant
Active reactors ( gross ):
Decommissioned Reactors ( gross ):
The nuclear power plant Neckarwestheim (joint nuclear power plant Neckar, GKN ) is a nuclear power plant in Neckarwestheim with two pressurized water reactors. Operators of the power plant is the EnBW subsidiary EnBW Kernkraft GmbH, headquartered in Obrigheim.
- 2.1 closure dates
- 2.2 Safety and accidents (selection)
- 3.1 Data of the reactor units
- 3.2 GKN I
- 3.3 GKN II
- 4.1 exhaust chimney
- 4.2 Bahnstromumformerwerk
- 4.3 Cooling Towers 4.3.1 cells cooler GKN I 4.3.1.1 Demolition of the cells cooler
- 5.1 Right of Way
- 5.2 Community Foundation
- 5.3 Greenpeace protest
Location
Both plants were built about 1 km southwest of Neckarwestheim on the site of a former quarry, 15 km south of Heilbronn. The power plant is located on a small part also on the boundary of the neighboring community Gemmrigheim.
Geological situation
The plant is partly due to disordered, verkarstetem limestone. By Subrosionsprozesse these layers decreases the soil surface were induced, which amounted to the cooling tower up to 14 cm.
History
Plans for Block I go back to the year 1970. After the originally planned construction of a nuclear power plant in the neighboring town Lauffen was not achieved and the Neckar works and the TWS agreed in January 1971 to build a nuclear power plant in the Neckar Westheimer quarry of Lauffener company's Portland Cement Factory (later ZEAG ) the later also acquired a stake in the operating company.
Originally, the plant was designed for a capacity of 600 megawatts ( there were a design both for a boiling water reactor and a pressurized water reactor before ). It was decided finally for the second variant, since this type of reactor already in Obrigheim was in operation and valuable experience over the operation of the plant could be obtained.
In 1971, the plans were modified and enhanced performance to 840 MW. The reason for this was that the then German Federal Railroad had only one small railway power plant, which would not be sufficient for the planned electrification of the rail network. That is why the German Bahn AG is still one of the shareholders of the power plant.
In January 1972, construction began, and even during the construction phase (1973 /74) the plans were changed again. Instead of a 160 m high natural draft wet cooling tower was decided to use the cells cooler. These were cheaper and also affecting the landscape less. On May 26, 1976, the reactor was critical, and on December 1, 1976, the transfer to the operator.
The Block II was still applied during construction of Block I in June 1975 by the operating company. Originally GKN II should be a " twin brother " of GKN I, that is a drawing of the same block, with 840 megawatts of electricity and cells coolers. At the turn of 1979/80, the plans were changed and designed a reactor of 1300 megawatts of electric power as well as a 160 -meter-high natural draft wet cooling tower.
The height and design of the cooling tower was - always changing - even for the sake of the landscape: first to 100, then to 80 and finally to 56 meters and in execution as a hybrid cooling tower. This version from 1981 was finally realized. In 1982 construction started for Block II, on 29 December 1988, the first criticality was reached and on April 13, 1989, the powerhouse of the operating company was passed. GKN II is so far the penultimate German nuclear power plant, which went online only block 5 of the Greifswald nuclear power plant later went to the net.
Closure dates
The operating company EnBW Kernkraft planned due to the nuclear phase-out to transfer a residual amount of electricity amounting to 46.9 TWh by the younger Block II on the older block I. The lower output of block I, the duration of which would have extended to the year 2017, while at the same time the term for GKN II would be reduced from 2021 to 2017, so that both blocks would have gone at the same time by the network.
The Federal Ministry of Environment ( Environment Minister Sigmar Gabriel ) opposed the application for EnBW residual amount of electricity transmission from the nuclear power plant Neckarwestheim II at the nuclear power plant Neckarwestheim I in June 2008. The most important criterion for this was the lower structural protection against aircraft crashes of GKN I compared to GKN II EnBW complained against the decision and operational Block I with reduced power, so that the reactor ( without extended downtime and without electricity transfers) the end of 2009 to In early 2010 his residual electricity volume of 10.25 TWh (as of 1 January 2008) would have produced, so that he would be taken off the grid must. Operation at reduced power to have served after allegations by Greenpeace to do not switch off the reactor prior to the 2009 federal election.
CDU / CSU and FDP had announced in the 2009 election campaign a term extension of German nuclear power plants, which they transpose in autumn 2010 also in the fact ( and after the Fukushima nuclear disaster (March 2011) revised).
EnBW operation before the nuclear phase four of the 17 German reactors. These four have a combined net capacity of 4,372 MW; Neckarwestheim I has 785 MW.
On January 21, 2010 2009 talks between the Federal Government and the four NPP operators (EnBW, EON, RWE, Vattenfall ) were first held after the change of government. Pending a final decision on a term extension of German nuclear power plants, GKN I should stay on the network. This was achieved by a reduction in performance. So GKN I ran in May 2010 with an average power of 19 percent of its capacity (150 MW from 785 MW).
On 28 October 2010, the Bundestag passed an energy concept, which also allowed a term extension of all 17 German reactors. Older reactors were eight years remain in use longer, newer reactors 14 years old. Block I would therefore be able to produce II to 2036 current and 2019, Block. The Act was published on 13 December 2010 in the Federal Gazette and entered into force the following day.
In November, 2010, EnBW considerations known to take Block I formerly from the mains. Whether this is actually intended EnBW or if you so wanted to criticize the decision taken on 1 January 2011 fuel tax, remained unclear.
After a nuclear summit in the wake of the earthquake in Japan on 11 March 2011 and its consequences Chancellor Angela Merkel announced on 14 March 2011 a three-month moratorium on nuclear. " The operator should the grid connections by 1980 nuclear power plants shut down for safety checks. All others are checked during operation -. Open-ended, like the Chancellor, the Federal Environment Minister and Federal Minister Rainer Brüderle stressed "
On 15 March 2011 the then Baden-Württemberg Minister President Stefan undersecretary announced the permanent closure of the block. From the EnBW voluntary intention to shutdown of Neckarwestheim I was announced, moreover, has been published by Hans -Peter Villis, CEO of EnBW, "that a permanent estate of GKN 1 and thus a restart of the nuclear power plant will probably no longer be displayed. " on 16 March 2011, GKN was I traversed (Ministry for the Environment, Nature Conservation and Transport Baden- Württemberg) in the evening after instructions of the competent nuclear regulatory authority and went into the night, along with block I of the nuclear power plant Philipp (KKP 1), from the network. " The step is justified by the fact that under the Atomic Energy Act ( § 19 paragraph 3) there had been a suspicion of danger, justifying a temporary cessation. Such a suspicion is according to the current legal situation already given if can not be completely ruled out due to reasonable uncertainties in the risk of damage prevention opportunities. "
Safety and incidents (selection)
Plant
Data of the reactor units
The nuclear power plant Neckarwestheim has a total of two blocks:
GKN I
The nominal electrical output of block I, which became operational in 1976, is 840 megawatts. After deduction of the own consumption accounts for approximately 630 megawatts to the delivery to the 220 kV grid and 150 MW to the network of Deutsche Bahn. The traction power generator used is the world's largest generator for single-phase. The built by Kraftwerk Union reactor belongs to the second generation of built in Germany pressurized water reactors and one of the few systems with only three instead of the usual in most reactors four reactor coolant loops.
At a voltage of 21,000 volts, the AC generator of block I provides a current of 27,000 amps at 50 Hertz, and the traction power generator at a voltage of 14,500 volts, a current of 12,000 amps with the usual current path 16.7 Hertz. The electricity produced by the generators is to 220 kV ( three-phase alternating current) or 110 kV ( single phase traction power ) highly transformed by the generator transformers. Block I is the only nuclear power station, which generates the traction current.
In a report of 2010 is written: " GKN 1 belongs to the investigations of the Society of Nuclear Safety to protected against a terrorist attack aircraft the least investment in Germany. "
End of May 2011 it was decided by the environment ministers of state and federal levels, shut down the block I permanently. As a first visible stage of demolition was begun in May 2012, the cells cooler disassemble. In September 2012, the demolition of the cooling towers to be completed.
GKN II
The nominal electrical output of Block II, which went into operation in 1989, is 1,400 megawatts. It is generated by the generator as a phase current with a voltage of 27,000 Volts and a current of 35,000 amps. In contrast to Block I does not track power generation takes place, but a part of the generated three-phase current in the immediately situated next to the switching of the block II be converted to Bahnstromumformerwerk traction power. The connection is made via the 380 kV generator transformer of the block II and the 380 -kV generator transformer of the three-phase machines of Umformersatzes. In this reactor block is a nuclear power plant, the convoy series. The reactor pressure vessel is a cylindrical steel tank with a height of 12 meters and an inner diameter of 5 meters. Its wall thickness is 25 cm and its curb weight of about 520 tons.
Structures
Exhaust chimney
The exhaust stack is 150 feet high and is shared by both units. In contrast to the radioactive content in the ash removal from coal-fired power plants no radioactive substances from semi- open systems are released.
Bahnstromumformerwerk
For GKN also heard another Bahnstromumformerwerk, built in reinforced concrete. The Bahnstromumformerwerk Neckarwestheim, which is located immediately adjacent to the turbine building of Unit II, has two sets of identical machines consisting of a twelve -pole three phase asynchronous motor and a four-pole Einphasensynchrongenerator. The nominal voltage of the three phase asynchronous motor and the traction current machine be 12.5 kV. The machine set has a length of 17.5 meters and a maximum width of seven meters. The nominal transmission capacity of each machine set 70 megawatts, which is the highest transmission power of all machine sets previously used in Bahnstromumformerwerken.
The Bahnstromumformerwerk feeds the generated traction power via appropriate transformers in the 110- kV traction power supply and is connected to the three-phase network via a 380 kV transformer in conjunction with each traction power, and each three-phase machine has its own transformer. The coupling with the generator in the Block II is possible only through the detour via the 380 kV network.
Cooling Towers
To avoid overheating of the Neckar water, have both Block I and Block II cooling towers. However, those are not carried out by different construction and conventional construction.
Cells cooler GKN I
Block I used two rows of cell cooling towers. Each series had a length of 186.8 meters, a height of 18 meters and a width of 16.9 m at the bottom and above 23.5 m.
In the cells of the cooling towers from the condenser coming, warm cooling water is cooled before it is fed back into the circuit. Alternatively, the cooled water could also be delivered directly back to the Neckar and replaced with fresh, cold water.
At sufficiently low water temperature of the river Neckar Block I worked with reduced power and bypassing the cells cooler. The Neckar were then taken up to 44 m³ / s of fresh water and given directly after the heating to cooling. Limit was to be complied with, regardless of the operating state, a maximum heating of the introduced into the Neckar cooling water at 10 ° C.
Demolition of the cells cooler
After Unit 1 was shut down in early 2011, began in June 2012, the demolition work for the cells cooler.
Hybrid cooling tower GKN II
Block II uses a hybrid cooling tower with a height of 51.22 meters. During the construction of the power plant, a low cooling tower was required because a convection based on natural draft cooling tower would have resulted in certain circumstances to an atomization of the Neckar valley at inversion conditions for visual landscape protection reasons. The hybrid cooling tower consists of two levels with 88 (2 times 44 ) electrically driven fans. The cooling tower is thus forced convection electric. The first level vented only the trickling water below the Rieselleitungen in the wet part, the second level vented only the ascending water vapor above the Rieselleitungen, in the dry part. The hybrid cooling tower is designed double-walled, and so very large water -carrying Konvektionskühlkörper were installed in the air stream for the second level in the interstices of the dry part. This structural gimmick, the air is preheated inside the cooling tower, so this draft for the second level is also of course forced. With this measure, the height could be kept within limits, for the cooling tower is slightly larger in base diameter. Than other comparable cooling towers with the same power The dry part of the cooling tower is also accessible during operation. This is also a lift, with which one can reach the second level provides. The cooling water circulates in a loop, a fresh water inlet or outlet cooling is in block II is not possible, in contrast to the block I. The line passing through the evaporation and blow down the amount of water lost is supplemented by recycled Neckar water resistant. The maximum withdrawal amount is placed at 700 l / s
Interim storage
The power plant has its own temporary storage, in the 151 Castor containers can be stored with a heavy metal weight of 1,600 tons to transport to a yet to be devised repository.
In May 2008, reported several media that may be of inferior concrete was used in the construction of the intermediate bearing. The message was confirmed by a report in February 2009, although safety-related parts are not affected.
Power lines
The electricity generated at the GKN is passed through a single, combined traction power and three-phase line to the east of nearby Neckarwestheim 220 kV AC and the 110 kV traction power switching device. This pipe is laid on pylons of unusual design with five trusses. At the lowest crossbar has two railway circuits, while the second, third and fourth traverse each a three-phase circuit wear. This is operated in the case of the GKN I with 220 kV and, in the case of the GKN II with 380 kV. On the top traverse two ground wires are installed.
It is striking in this line that the path circuits have been isolated for 220 kV, although they are operated with 110 kV. This measure was taken because in case of failure of the parallel 380 kV line surges can occur where an insulation for 110kV has not grown. The traction current lines from GKN for traction current switching Neckarwestheim and from there to the central sub-station in Stuttgart- Zazenhausen (see traction current Neckarwestheim - Zazenhausen ), apart from a return train power line in Kreiensen the only configured as four bundles traction current lines.
The nuclear power plant from the GKN II leads away, operated with 380 kV three-phase circuit runs at 220 - kV three-phase switching Neckarwestheim over to the substation Großgartach near Heilbronn. For GKN still performs a single-circuit 110- kV line, which takes its origin in the switching of the power plant Walheim. It does not serve the evacuation of generated power in GKN, but in the case of the arrest of GKN to its energy supply.
It is also noteworthy that Neckarwestheim and GKN, with the exception of a (now dismantled ) Loren path to the cement plant in Lauffen, never on a track connection to the railway network has have.
Bahnstromumrichterwerk
2010/2011 was a Bahnstromumrichterwerk south of the power plant site built with 140 MW of power to replace the decommissioned GKN I. It is powered by a 380 kV underground cable from the GKN II.
Others
Right of Way
On the banks of the Neckar an old towpath runs through the premises of the power plant. To ensure this path still existing right of way on the Neckar River is each score in the security fence, where you can ring as a walker to traverse the premises in the company of GKN guards along the way.
Community Foundation
In the late 1980s, after the commissioning of GKN II, planned the operator of the power plant to build a power plant site adjacent to the public swimming pool and operate. This should be heated with waste heat from the power plant and be open in the winter. Since this was different views among the inhabitants of the communities Neckarwestheim and Gemmrigheim, decided the local councils of the two communities to be carried out a referendum over the bath. In Neckarwestheim citizens voted in the majority for the bathroom, in Gemmrigheim there was a majority against the bath. It was found a compromise: The operating company paid the expected construction costs ( estimated were about DM 20 million) in a community foundation established in 1993 a. The interest income of the Foundation to get the citizens of Neckarwestheim and Gemmrigheim at a cost of 10 euros annual passes for the pools of several surrounding communities. Children get the card for 5 euros. There are also in winter a shuttle service to and from nearby indoor swimming pools.
Greenpeace protest
On 28 February 2011, Greenpeace activists occupy the hybrid cooling tower to demonstrate against security flaws in Block I. They also unfurled banners and painted a skull with the slogan "Nuclear power harms the home team " to the cooling tower. 28 activists chained themselves firmly to the cooling tower. 52 on the action involved were arrested.