Nuclear power plants in Germany

Author: Dr. Klaus Hassmann, Cluster Energietechnik (As of February 2018) In Germany, the release of the technology by the victorious powers in the 1950s caused a nuclear awakening mood for decades that was supported by politics; the author experienced it as a young engineer in the late 1960s.  In competition with nations that had begun investigations into the peaceful use of nuclear power earlier, the federal and state governments established research centers; universities also established many relevant chairs, and students flocked in large numbers to the new high-tech field of research; much technical knowledge was also developed in industry, for example in the areas of fuel (uranium/ thorium/ plutonium), cooling, moderation (brakes the neutrons to the low thermal energies required for the chain reaction), core and system design, construction, materials, fabrication, nuclear safety in theory and practice (laboratory tests up to prototype plants);  different building blocks were tested by experts for their suitability for large-scale application, implementation and economic viability. Despite this, misjudgments by decision-makers in industry and politics, supported in part by science, led to construction decisions that cost a lot of money and achieved little to nothing. After the decision to phase out nuclear power - the last power plant will go off the grid in 2022 - the era of nuclear energy in Germany will end after about 60 years; the detailed knowledge is thus stored in the minds and written legacies of about 2 generations. Nuclear know-how will still be needed for dismantling nuclear reactors and handling nuclear waste.

Pressurized Water Reactor (PWR)

Manufacturer in Germany (D): except for one plant (see 2.), Siemens initially built the PWR in a collaboration with Westinghouse later as an in-house development; the PWR is contributed to Kraftwerk Union (KWU, AEG/Siemens 50% each) in 1973; Siemens takes over AEG shares in KWU in 1975; the nuclear division was spun off in July 2000 under the name Siemens Nuclear Power (SNP), which is merged into Framatome ANP (Siemens 34%) in 2001; Siemens sells its shares to ANP parent Areva in 2011.

 1. First commercial power plant PWR

^*) Terawatt hours; for comparison: gross electricity generation in D in 2013: 631 TWh 

2. The nuclear power plant (PWR) that should never have been built 

KMK was built and commissioned in an earthquake-prone area despite numerous objections; after a decision by the Federal Administrative Court in Berlin, the plant had to be shut down after 1.5 years of operation. It did not go back into operation and was decommissioned; some systems/components in the nacelle were sold abroad.

Boiling Water Reactor (BWR)

Manufacturer in Germany (D): AEG under license from General Electric (GE); AEG brings the BWR into KWU in 1969 - thereafter like PWR.

3rd prototype BWR 

4. Failed as a commercial BWR plant - an experimental power plant emerges     

   Cost reduction                                    

Due to damage to fuel elements as well as additional problems, it was decided not to pursue the HDR construction line; a planned conversion of the plant by AEG into a steam-cooled breeder reactor or a conventional light water reactor also failed; thereafter used as a non-nuclear test plant; final decommissioning in 1992.

Summary Light Water Reactor: PWR and BWR developed into the dominant nuclear power plant technologies in D due to their increasingly mature technology and safety compared to the alternatives described below, as well as their reliable operation; the PWR was ahead of the BWR; thus, towards the end of the 1980s, three PWR power plants (Konvoi) of identical design and construction by the manufacturer KWU went on line in D. They are still today (2017) at the net.

Heavy water reactor (D2O PWR)    

5. Prototype D2O PWR

Summary Heavy Water Reactor: For cost and also dependency reasons, enriched uranium was to be avoided as much as possible - one relied on natural uranium as fuel. However, these considerations did not prevail over the years. Siemens/KWU built a P2O PWR with a capacity of 357 MW in Atucha, Argentina, which went into operation in 1975. Construction of the 2nd Atucha reactor with 745 MW began in 1982; In 2006, the Argentine government decided to complete the CNA II plant, which was 85% complete by then, under NASA's leadership. NASA emerged from ENACE, founded in 1980 between arg. CNEA and Siemens/KWU with the goal of continuing the development and construction of nuclear facilities in Argentina. CNA II was completed and handed over to commercial operation in early 2015. 

Gas-cooled reactor

6th CO2 Pressurized Tube Reactor (CO2-DR)                    

Niederaichbach(KKN) 

The shutdown in 1974, after such a short time, was due to technical problems, e.g. with the high-temperature heat exchanger (500°C/>100 bar), but mainly because it was not economically viable.

7. High temperature pebble bed reactor (experimental reactor)

Trial Reactor (AVR-Jülich)

8. High temperature pebble bed reactor (commercial reactor)                                      

Reactor (THTR)    

High temperature pebble bed reactor conclusion: the development of this reactor line was generally considered to be safe for core meltdown in terms of the extent of fission product release during a super accident. After the experience in the AVR and THTR, there were doubts about this prognosis - air inrush can lead to fires, steam or water supply to release flammable gases (H2) as well as criticality ramp. In this environment, coupled with susceptibility to accidents and lack of economic viability, even in competition with the light water reactor that is becoming established on the German market, led to the fact that the proposal of a construction consortium could no longer find partners willing to finance and operate a 500 MW reactor.

Sodium-cooled reactor

9th fast breeder reactor (prototype)

10. Fast breeder reactor designed and built as a commercial plant

 Reactor core/plant technology

Fuel rods cylindrical in BE; incubator jacket for incubation of fissile material/2 Na cycles

Summary sodium incubator: despite extensive and also positive experience from KNK operation, the technology failed for several reasons: Kalkar is located in NRW; the state government promulgated a coal priority policy for electricity and denied the operating license for SNR 300; in 1989, reprocessing in Wackersdorf is overturned, on which breeder reactors in the state of their operation generally depend. Light water reactors established themselves as safe and reliable power generators - other reactor types were less economical. The reactor disaster in Chernobyl in 1986 also caused fears and additional rejection.

The two large power plants fast sodium-cooled breeder reactor (SNR 300) and the pressurized water reactor Mülheim Kärlich were not in operation at all or only for a short time; they cost the national economy a low two-digit billion Deutsche Mark amount. Reflected in this, the expenditures for the development of competences, the construction and operation of experimental plants (VA) and prototype power plants (PK) of small capacity were low. However, the demolition of VAs and PKs of small capacity until the greenfield site is restored is many times more expensive than the construction of these plants.