Research reactor diorite
| Research reactor diorite | ||
|---|---|---|
Aerial view of the Diorit research reactor (23 May 1960) |
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| location | ||
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| Coordinates | 659 438 / 265619 | |
| height | 335 m above sea level M. | |
| country |
 Switzerland
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| Data | ||
| owner | Paul Scherrer Institute | |
| operator | Paul Scherrer Institute | |
| start of building | January 1, 1957 | |
| Installation | October 10, 1960 | |
| Shutdown | 7th July 1977 | |
| Reactor type | Heavy water reactor | |
| Thermal performance | 30 MW | |
| Neutron flux density | 4.0 × 10 13 n / (cm 2 s) | |
| was standing | February 2, 2009 | |
Diorit was the name of a research reactor of the Federal Institute for Reactor Research (EIR) in Würenlingen ( Canton Aargau , Switzerland ).
This nuclear reactor was operated by the EIR from 1960 to 1977. The moderator was Heavy Water (D 2 O). In addition, the heavy water was used as a coolant. The reactor originally commissioned in 1960 had a thermal output of 20 MW. The fuel used in the research reactor was initially natural uranium and later enriched uranium, with the 2-meter-long aluminum-clad and nickel-clad fuel elements from the Canadian company AMF Atomics Canada Ltd. were manufactured.
Military backgrounds
Heavy water ( deuterium ) has a particularly good neutron economy, which in turn is particularly suitable for the production of high-quality weapons plutonium . Although the diorite was in fact used for civil research purposes, it was never diverted from weapon plutonium. As the historian Jürg Stüssi-Lauterburg showed in a study of meeting minutes that had previously been classified as secret, the Swiss military felt entitled to see Switzerland as a nuclear threshold power during the Cold War because of the diorite . It was publicly known that during certain phases of the Cold War the army was clearly striving for nuclear armament. For example, For example, a Solothurn major in 1957 wrote the following sentence in a jubilee publication: ... Military considerations therefore force the procurement of nuclear weapons even for a state whose army is limited to defense.
Accident in 1967
In 1967 the diorite produced a melted fuel element that contaminated the reactor hall. Significantly higher levels of radioactivity were also registered in the Aare . As a result of the accident, the entire primary heavy water cooling system had to be decontaminated by pickling.
Conversion to Diorit II
As a follow-up to the accident in 1967, it was decided to replace the reactor tank. The conversion served, among other things, to switch from operation as a natural uranium reactor to operation with enriched uranium dioxide as fuel. During the renovation work, individual workers were exposed to increased doses of radiation, which were individual doses of up to 1020 mrem, while the highest total accumulated personal dose was 2600 mrem (26 mSv).
Dismantling
The Diorit research reactor has not been operated since 1977. The first dismantling plans were drawn up in the early 1980s. The final shutdown was decided in 1994. When the diorite reactor was decommissioned, the following quantities of radioactive waste were produced: u. a. 250 tons of steel, 120 tons of concrete, 5.4 tons of aluminum and alloys and 45 tons of graphite.
The burned-out fuel rods from the diorite reactor are stored in a Castor 1c diorite container and were transported to the Zwilag central interim storage facility (ZZL) in 2004 .
See also
Web links
- Asbestos during the dismantling of the Diorit research reactor in Switzerland. Rhombos Verlag / Forumz - Network of Municipal Waste Management , May 9, 2006, accessed on July 13, 2016 .
Individual evidence
- ↑ a b c Conrad H. 1972: Radiation protection problems when converting the heavy water reactor Diorit. Nuclear Research Center Karlsruhe KFK 1638 Conference from 17.-19. May 1972 in Karlsruhe: Radiation protection in the workplace, pp. 79–87. ( PDF ).
- ^ Cole TE & Weinberg AM 1962: Technology of research reactors. Annu. Rev. Nucl. Sci. 12: 221-242 ( online ).
- ↑ Mityaev Yu. 1964: Montreal power reactor conference. Translated Atomnaya Energiya, Vol. 16, No. 3, pp.272-273. March, 1964 ( doi: 10.1007 / BF01122987 ).
- ↑ J. Stüssi-Lauterburg: Historical outline on the question of Swiss nuclear armament , 1995.
- ↑ 100 Years of Solothurn Officers Society , 1957.
- ↑ Beer H.-F. 2009: Radioactive waste management at the Paul Scherrer Institute - The largest Swiss National Research Center. Nuclear Technology & Radiation Protection 3/2009 pp. 212-217 ( PDF ).
- ↑ Federal working group for nuclear waste disposal: 27th activity report of the federal working group for nuclear waste disposal. Federal Office for Energy SFOE, April 1, 2005.