Berlin experimental reactor

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Berlin experimental reactor
Berlin experimental reactor (Berlin)
Berlin experimental reactor
Coordinates 52 ° 24 '35 "  N , 13 ° 7' 42"  E Coordinates: 52 ° 24 '35 "  N , 13 ° 7' 42"  E
country Germany
Data
operator Helmholtz Center Berlin
start of building BER I : 1956
BER II : October 10, 1970
Installation BER I : July 24, 1958
BER II : December 9, 1973
Shutdown BER I : Summer 1972
BER II : December 11, 2019
Shutdown BER I : April 23, 1974
Reactor type BER I : homogeneous. Solution
BER II : swimming pool
Thermal performance BER I : 50 kW
BER II : 10 MW (from 1991)
Neutron flux density BER I : 1 × 10 12 n / (cm 2 s)
BER II : 2 × 10 14  n / (cm 2 s)
Website Homepage at the HZB
was standing January 28, 2020

The Berlin experimental reactor is a former research reactor that was operated on the site of the Helmholtz Center Berlin for Materials and Energy (formerly the Hahn-Meitner Institute for Nuclear Research ) in Berlin-Wannsee . The first reactor under this name, BER I , was in operation between 1958 and 1972, the successor BER II was used from 1973 to 2019.

The BER II has a nominal output of 10 MW and was used exclusively as a neutron source for research purposes. It was shut down in December 2019 and is to be dismantled, which Template: future / in 5 yearsshould be possible by 2033 at the earliest .

history

The planning for the predecessor reactor BER I began in 1956 when two research reactors type L-54 ( one for Frankfurt / Main , the other for West Berlin) with 50 kW power were ordered from the US company Atomics International . At this point in time, there was neither a license from the USA to operate a nuclear reactor in West Berlin (this was granted retrospectively in April 1957), nor was there a contractual basis with the US Atomic Energy Commission for delivery. The construction of the reactor could only begin after the US Atomic Energy Act was amended in the USA. With the laying of the foundation stone for the later Hahn-Meitner Institute , construction work on the reactor began on May 25, 1957. After the passing of a separate nuclear law in West Berlin, which is necessary for operation, by order of the Allied Command according to a specification by the USA, the uranium enriched to 20% could be delivered as a solution in two vessels by plane to Berlin-Tempelhof Airport . Shortly afterwards, on July 24, 1958, the research reactor reached its first criticality . The Hahn Meitner Institute itself was inaugurated a year later on March 14, 1959 with the presence of the namesake Otto Hahn and Lise Meitner .

On October 10, 1970, after a discussion process that had begun in mid-1966, the construction of a new successor reactor began. The reactor had to be shut down in the summer of 1972 after irreparable damage in the recombiner for the radiolytic oxyhydrogen gas. The operating license was revoked by the then Senator for Economics Karl König after the Bonn Ministry of Science had failed to accept liability . Decommissioning began on February 15, 1974. The 26.4 liters of fissile solution only leased by the USA were transferred to Eurochemic in Mol (Belgium) and transported by air into two transport containers . The reactor was irreversibly converted into radioactive waste , which was taken into the care of the local state collection point . With the safe enclosure of the reactor remains at its location, the BER I research reactor was finally released from the scope of the Atomic Energy Act on April 23, 1974 .

The successor reactor BER II with an initial output of 5 MW was put into operation on December 9, 1973. From 1985 to 1989 the reactor was expanded to an output of 10 MW and better experimentation possibilities and was put back into operation in 1991. From August 1997 to February 2000, the reactor was gradually converted from highly enriched uranium to low enriched (19.75%) uranium.

In June 2011 a team from ARD reported that there was supposed to be a crack in the cooling system of the research reactor. This representation was denied by Berlin's Senate Department for Health, Environment and Consumer Protection. The Helmholtz-Zentrum Berlin also stated in a press release that the ARD report was based on “malicious allegations” by a former employee.

On November 29, 2013, the reactor was shut down for safety reasons. The reason was a crack in a device that is used to partially pump out the water basin for maintenance; H. no safety-relevant system. An additional high-performance magnet was installed during maintenance. Operations resumed in early 2015.

construction

The BER I research reactor was a homogeneous reactor in which the nuclear fuel , a uranyl sulfate solution (UO 2 SO 4 ), was dissolved in distilled water . Here, less than 20 percent enriched uranium was used. For focusing the neutrons graphite - reflectors used, the thermal neutron flux density was 10 12  cm -2 s -1 .

In contrast, the BER II research reactor is a swimming pool reactor that is cooled and moderated with light water . 24 fuel elements with 322 grams of uranium each and six elements for holding the control rods with 238 grams of uranium each are in use. The neutrons are bundled with beryllium reflectors, the thermal neutron flux density of 2 · 10 14  cm −2 s −1 is around 200 times higher than with BER I. The neutrons are transported through nine beam pipes from the reactor core through the water basin and the concrete shield to the experimental facilities directed. The primarily desired reactor core with innovative UZrH fuel elements for pulse operation, as in the case of TRIGA reactors with the option of continuous operation as an innovation, was removed again during testing after the exchange of the first MTR core due to unexpectedly high and unrecoverable fission product emissions and replaced by an MTR -Core replaced.

safety

Due to the small power, the absence of circuits under pressure, the completely passive cooling and the large, shielding amount of water, the release of radioactivity in a swimming pool reactor of low power is very unlikely. In the case of BER II, the control rods fall into the core due to gravity alone and switch off the reaction; the decay heat is dissipated by natural convection .

According to the opinion of opponents of nuclear power, a dry core meltdown at BER II would at least result in a serious accident, i.e. H. "Substantial release (some 1,000 to some 10,000 TBq), full use of disaster control measures" and thus level 6 on the seven-point scale . According to the Berliner Zeitung, large parts of Potsdam and Berlin would be affected if radioactivity was released . As a target for attacks, however, this reactor is considered uninteresting due to the small amount of fuel, both in comparison to other nuclear facilities and, above all, to chemical industrial facilities, highly populated areas or public events.

A flight route from Schönefeld Airport is not far from the reactor. The reactor is not secured against plane crashes. The Reactor Safety Commission (RSK) recommends checking the fire-fighting measures provided for the reactor with a view to fuel fires after a large aircraft crashes. The possibility of terrorist attacks was ignored in the RSK study with reference to the existing time frame. In a radius of 3 nautical miles (= 3.704 km) around the reactor, the restricted flight area "ED-R 4 (Wannsee)" was created, which extends from the ground to an altitude of 2200 feet (approx. 660 meters) above sea level. The use of airplanes or model aircraft in this airspace is only permitted with the prior approval of the Federal Supervisory Office for Air Traffic Control .

Reportable Events

Notifiable events are passed on by the system operator to the Federal Office for Radiation Protection via the competent state authority. Here is a selection of the significant events for BER II:

  • July 20, 1998: Automatic reactor shutdown after a converter failure.
  • June 16, 1999: Reactor shutdown due to operating errors when comparing the power range instrumentation.
  • May 23, 2000: Reactor shutdown due to the permissible reactor power being exceeded due to a fault in the reactor control channel.
  • February 13, 2001: Reactor shutdown after a strong increase in output and exceeding the permissible reactor output.
  • February 9, 2005: Manual reactor shutdown after failure of the operational control system.
  • October 16, 2006: Reactor shutdown due to exceeding the permissible reactor power due to incorrect operation.
  • August 8, 2009: Reactor shutdown after incident of a control rod.
  • July 5, 2010: When a sample was withdrawn from the reactor core, the output of the reactor was not properly readjusted. As a result of this incorrect operation, the output of the reactor increased so much that the permissible output limit was clearly exceeded and the automatic reactor shutdown had to intervene.
  • December 13, 2015: Failure of one of the four measuring chambers, which are located at the corners of the cube-shaped system named BER II. "Unbalanced load" of 25 percent and automatic rapid shutdown of the reactor.

See also

Web links

Individual evidence

  1. ↑ Thomas Prinzler: BER II is history. In: rbb24.de , December 11, 2019, accessed on December 13, 2019.
  2. ↑ RF Wilson et al .: Aqueous Homogenous Type Research Reactors , Second United Nations International Conference on the Peaceful Uses of Atomic Energy, June 1958, A / CONF.15 / P / 1543, DOI: 10.2172 / 4315502
  3. ^ Burghard Weiss: Großforschung in Berlin, pp. 116–126. Campus Verlag, Frankfurt / Main 1994. ISBN 3-593-35133-1
  4. ↑ 50 years ago: laying of the foundation stone for today's HMI in Wannsee ( memento of the original from January 10, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , Press release of the Hahn-Meitner-Institut from May 25, 2007 @1@ 2Template: Webachiv / IABot / www.helmholtz-berlin.de
  5. ^ Burghard Weiss: Großforschung in Berlin, p. 351. Campus Verlag, Frankfurt / Main 1994. ISBN 3-593-35133-1
  6. ↑ Report on the status of the BMBF decommissioning projects and the BMBF-funded R&D work on “Decommissioning / dismantling of nuclear facilities” ( Memento of the original from January 10, 2014 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , PTE-S No. 2, Research Center Karlsruhe, September 2001. @1@ 2Template: Webachiv / IABot / www.ptka.kit.edu
  7. ↑ Federal Office for Radiation Protection: List of nuclear facilities in the Federal Republic of Germany (decommissioning) ( Memento from January 10, 2014 in the Internet Archive ), November 2013, accessed on January 10, 2014.
  8. ↑ Federal Office for Radiation Protection: List of nuclear facilities in the Federal Republic of Germany (operation) ( Memento from January 10, 2014 in the Internet Archive ), November 2013, accessed on January 10, 2014.
  9. ↑ Helmholtz Center Berlin - Research Reactor BER II: Reactor data ( Memento from January 15, 2012 in the Internet Archive )
  10. ^ Nuclear Threat Initiative: Germany ( Memento from March 22, 2011 in the Internet Archive )
  11. ^ Safety deficiencies in the Berlin research reactor , rbb press kit from June 9, 2011
  12. ^ Opinion on the article by the ARD policy magazine KONTRASTE from June 23, 2011 ( Memento of the original from July 8, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , Senate Department Environment Berlin @1@ 2Template: Webachiv / IABot / www.berlin.de
  13. ↑ Helmholtz-Zentrum Berlin rejects claims by the ARD magazine Kontraste , Helmholtz-Zentrum Berlin (HZB)
  14. ↑ Berliner Tagesspiegel: Wannsee reactor shut down - public was not informed , July 8, 2014
  15. ^ After the repair break, the Wannsee research reactor is running again , Die Welt , February 19, 2015
  16. ↑ Reactor data of the Berlin experimental reactor ( Memento from January 15, 2012 in the Internet Archive ), Helmholtz Center Berlin for Materials and Energy
  17. ^ Burghard Weiss: Großforschung in Berlin, pp. 347-349. Campus Verlag, Frankfurt / Main 1994. ISBN 3-593-35133-1
  18. ↑ Safety analysis method in case of black-out accident on pool type research reactor , Progress in Nuclear Energy, 2015, accessed October 8, 2015
  19. ↑ Safety Analysis for Research Reactors , IAEA , 2008. Retrieved October 8, 2015
  20. ↑ What is being done for safety? , Helmholtz Center Berlin for Materials and Energy , accessed on October 8, 2015
  21. ↑ a b Anti-Nuclear Alliance in Berlin and Potsdam - FAQ. (No longer available online.) In: www.atomreaktor-wannsee-dichtmachen.de. Archived from the original on April 20, 2016 ; Retrieved April 20, 2016 .
  22. ↑ Berliner Zeitung: Safety deficiencies in the Wannsee research reactor: Radioactivity for all of Berlin , June 20, 2012.
  23. ↑ Regulations for dealing with model aircraft and unmanned aviation systems in Berlin. Retrieved June 20, 2018 .
  24. ↑ Use of unmanned aerial vehicles in Berlin (drones, model aircraft, RPAS, UAS, UAV, etc.). Retrieved June 20, 2018 .
  25. ↑ Federal Office for the Environment, Nature Conservation and Nuclear Safety: Notifiable events in plants for the fission of nuclear fuels in the Federal Republic of Germany, Annual Report 1998
  26. ↑ Federal Office for the Environment, Nature Conservation and Nuclear Safety: Notifiable events in plants for the fission of nuclear fuels in the Federal Republic of Germany, 1999 annual report
  27. ↑ Federal Office for the Environment, Nature Conservation and Nuclear Safety: Notifiable events in plants for the fission of nuclear fuels in the Federal Republic of Germany, Annual Report 2000
  28. ↑ Federal Ministry for the Environment, Nature Conservation and Nuclear Safety: Notifiable events in plants for the fission of nuclear fuels in the Federal Republic of Germany, annual report 2001
  29. ↑ Federal Ministry for the Environment, Nature Conservation and Nuclear Safety: Notifiable events in plants for the fission of nuclear fuels in the Federal Republic of Germany, annual report 2005
  30. ↑ Federal Ministry for the Environment, Nature Conservation and Nuclear Safety: Reportable events in plants for the fission of nuclear fuels in the Federal Republic of Germany, Annual Report 2006
  31. ↑ Federal Ministry for the Environment, Nature Conservation and Nuclear Safety: Notifiable events in plants for the fission of nuclear fuels in the Federal Republic of Germany, annual report 2009
  32. ↑ Federal Ministry for the Environment, Nature Conservation and Nuclear Safety: Notifiable events in plants for the fission of nuclear fuels in the Federal Republic of Germany, monthly report 7/2010 .
  33. ↑ Helmholtz Center reports incident at the research reactor. In: tagesspiegel.de. March 24, 2016, accessed January 17, 2018 .