Castor (nuclear technology)
CASTOR ( English ca sk for s torage and t ransport o f r adioactive material "Containers for the storage and transport of radioactive materials") is an internationally protected brand name of the Society for Nuclear Service (GNS).
Castors are special containers for the storage and transport of highly radioactive materials , for example spent fuel elements from nuclear power plants or waste products (" glass canisters ") from reprocessing .
In general German usage, “Castor” is also used as a synonym or generic name for fuel element containers or containers for highly radioactive waste .
construction
The transport and storage container has a gross total mass of 110 to 125 tons. It essentially consists of a thick-walled, cylindrical container body made of nodular cast iron with the standard designation GJS-400-15C or forged steel for the lifting pins and a double-lid sealing system. The sealing lids are screwed to the container body and equipped with long-term resistant metal seals. On the outer surface there are axial or radial cooling fins for passive heat dissipation of the decay heat . For transport, shock absorbers are attached to the base and cover to reduce any possible accident-related shock loads . A castor costs around 1.5 million euros.
In accordance with the interim storage permits, the containers are approved to hold a maximum of 180 kg of radioactive substances with an activity inventory of a maximum of 1.2 · 10 18 Bq . The Castor V / 19 (PWR) and Castor V / 52 (BWR) casks are allowed to hold a radioactive inventory up to a maximum decay power of 39 kW. Inside, the temperature of the fuel rod cladding remains below 370 ° C. The moderator material in the Castor wall is designed up to a temperature of 160 ° C; the hall floor on which the castors stand must be designed up to 120 ° C and the hall walls up to 80 ° C. The exhaust air temperature above the castors is assumed to be 55 ° C.
variants
The types CASTOR V / 19 (for 19 fuel elements from pressurized water reactors ) or CASTOR V / 52 (for 52 fuel elements from boiling water reactors ) are mostly used for the transport and interim storage of spent fuel elements . Both types can hold around 10 tons of cargo (of which a maximum of 0.18 tons of radioactive substances).
Highly radioactive glass canisters from reprocessing that have already been returned have so far been transported and stored in CASTOR HAW 20/28 CG containers. These are about 6 m long, have a diameter of around 2.50 m and a 45 cm thick wall. Loaded containers can have a mass of up to 117 tons.
In 2008, TN 85 containers were used to transport the glass canisters from reprocessing in France . In 2010, containers of the new CASTOR HAW28M type were used for the first time. These containers can dissipate a heat output of 56 kW.
For further storage, it is planned (as of 2003) to open the containers again and to move the waste to Pollux containers.
safety
The on-site interim storage facilities contain in their permits for these containers a maximum permitted surface dose rate of 0.35 mSv / h, of which a maximum of 0.25 mSv / h may be caused by neutron radiation (i.e. staying for one hour directly next to the container results in a dose 0.35 mSv, which corresponds to around a seventh of the normal annual radiation exposure of the population of 2.5 mSv).
The safety and suitability of Castor and other storage and transport containers for radioactive material is also regularly discussed at the international PATRAM symposium .
Safety regulations in Germany
Legal basis
The Atomic Energy Act regulates u. a. dealing with nuclear fuel and thus also dealing with spent fuel elements. In accordance with Section 4 of the Atomic Energy Act , their transport and, in accordance with Section 6, their storage require a permit from the Federal Office for the Safety of Nuclear Waste Management (BfE).
The transport and storage containers are also approved by the BfE. The BfS commissions the Federal Institute for Materials Research and Testing (BAM) as an expert . As part of the approval process, the manufacturers must provide test results and evidence.
The transport of heat-generating waste (e.g. glass canisters) must be applied for and approved by the BfE.
Type B packaging
Castor containers are so-called type B packaging and also meet the acceptance requirements of the central and decentralized transport container warehouse in Germany. For type B packaging, a type approval is required in accordance with traffic law, for which the Federal Office for Nuclear Disposal Safety (BfE) is responsible in Germany .
Type B packaging must withstand all mechanical and thermal loads that occur during normal transport and in the event of serious transport accidents. Your safety functions must not be significantly impaired even in the event of a serious accident, so that no radioactive substances from the packaging can get into the environment. The Federal Institute for Materials Research and Testing (BAM) tests the mechanical and thermal properties of the packages as an expert on behalf of the BfS. As part of the approval process, the manufacturers must provide test results and evidence.
In Germany, the requirements for castor containers correspond to the recommendations of the International Atomic Energy Agency (IAEA). According to this, containers would have to withstand the following accident scenarios:
- Impact from a height of 9 m on an unyielding foundation
- Impact from a height of 1 m on a 15 cm thick steel mandrel
- Fire (30 minutes at 800 ° C )
- Pressure from 20 m water depth for eight hours
- Pressure of 200 m water depth for one hour (additional according to IAEA recommendations)
Mathematical evidence or the test of a (true-to-scale) model is sufficient for proof . The first three accident scenarios could be carried out one after the other on the same model. The container does not have to remain completely undamaged, but the shielding effect of the container may deteriorate by a maximum of a factor of 100 (to 10 mSv / h ( millisievert per hour at a distance of 1 m)). Falling from a height of 9 m means that the speed of the containers when they hit the surface is around 48 km / h.
In addition to the prescribed tests, others are carried out. For example:
- Fall of a container from a motorway bridge from a height of 40 m,
- If a container cooled to −40 ° C falls from a height of 9 m,
- Explosion of a liquid gas tanker with 5 t propane right next to a container,
- Fire test at 1200 ° C for 30 min,
- Dropping a scale container from a helicopter from a height of 800 m,
- direct impact of a passenger train at 130 km / h on the long side of a container,
- Shelling of a container with a 1000 kg replica of an aircraft turbine shaft at 292 m / s (1050 km / h).
The manufacturer states that these tests did not impair the safety functions and that they remained pressure-tight.
Criticism of security
Test procedure
Critics doubt the informative value of the experiments, test series and extrapolations for the safety of the various Castor containers or corresponding containers. Empty containers were used for previous tests, so they were a little lighter than in the use case. In the meantime, reproduced inventories are used in drop tests, the dimensions and mechanical properties of which correspond to the original inventory. Many experiments were carried out with reduced models on a scale of 1: 2, the statics of which correspond approximately to the originals. Critics compare this to crash testing cars where nobody would rely on miniature tests .
After all, for a long time, various tests were completely dispensed with and only theoretical calculations were used instead. After independent observers identified miscalculations in the assessment of the fall on a concrete floor in July 2002, new calculations were made that were kept under lock and key until December 2005.
Approval is only requested for newly developed containers. For variations of containers that have been tested once, no new approval procedures are carried out as standard, for example if a different insert basket is used or a completely different shock absorber (end cap) is used.
More scenarios
In addition to this general skepticism, there is also specific criticism of the prescribed test procedure.
- The heat test does not realistically cover some scenarios if, for example, large amounts of flammable material are involved in an accident. In the event of a collision with a tanker truck, especially in a tunnel, it is likely that temperatures above the intended 800 ° C will arise and the fire will last longer than half an hour. (Example: In 1999, the fire triggered by a burning truck in the Mont Blanc tunnel lasted over 50 hours).
terrorist attacks
Security is understood to mean the necessary protection against disruptive measures or other third-party influences (SEWD). In particular, acts motivated by terrorism are also considered as SEWD. The analyzes of the safety authorities, among other things, are included in the general requirements for security, which are defined by the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety . According to Section 4 of the Atomic Energy Act, the license for the transport of nuclear fuels is to be granted “if the necessary protection against disruptive measures or other third-party influences [SEWD] is guaranteed” (Section 4 AtG, Paragraphs 2, 5). When approving the transport of nuclear fuels, the Federal Office for Nuclear Waste Disposal Safety, as the competent licensing authority, checks whether the specified requirements are met through safety measures.
Jurisprudence
Courts never saw these arguments as a reason to question the safety of the containers used. The critics failed in all legal proceedings. The judges regularly followed the arguments of the experts from the licensing authorities and confirmed the legal admissibility of the temporary storage or the use of the containers used.
Transport of Castor containers to and in Germany
Most of the Castor containers are transported as freight trains . Road transport is usually carried out where there are no rail systems, for example in the last few kilometers between the loading crane near Dannenberg (Elbe) and the Gorleben transport container storage facility . In Germany, due to the nuclear phase-out, transports of the spent fuel elements from the nuclear power plants to the reprocessing plants were stopped on June 30, 2005; Instead, the Castor casks serve as interim storage facilities, which are often located at the respective power plant locations. In the reprocessing plant at La Hague nuclear fuel from German nuclear power plants located were transported to the Gorleben interim storage facility until November 2011th The fuel elements from the Sellafield WAA are to follow in the years 2014 to 2017. In Germany, there is great resistance in parts of the population to the transport of highly radioactive waste. The biggest protests regularly cause the radioactive waste to be transported back from the La Hague reprocessing plant in France to the Gorleben interim storage facility . At demonstrations and sit-ins regularly participate several thousand people . On site in the Lüchow-Dannenberg district there is a strong tradition of protest with a well-developed infrastructure . There are also regular protests and blockades along the transport route in Germany.
The criticism of the opponents is not generally directed against the return of German nuclear waste to Germany. This also shows the participation of French environmental activists in the blockades along the transport route and in Wendland . The protests are generally directed against the continued production of further nuclear waste in the current nuclear power plants and especially against the Gorleben repository site , which is viewed as unsuitable and dangerous. Not only the local population fears that the transports to the Gorleben transport cask storage facility will consolidate the political decision in favor of the repository. In contrast, decentralized interim storage facilities at the power plant locations shorten the transports to the interim storage facility and are not a preliminary decision for a specific repository location.
Increased Castor demand as a result of the exit decision in 2011
2011, the German government decided after the Fukushima nuclear disaster a nuclear phase-out . Eight of the 17 German nuclear reactors were shut down immediately, the remaining plants were phased out by 2022 at the latest. The operators of the nuclear power plants can start dismantling at the earliest when the fuel rods have been removed from the reactors and stored in castors. In order to be able to meet the increased demand for containers due to the nuclear phase-out, the manufacturing company GNS has increased its production capacity. The containers have had the necessary updated approvals since 2010 (CASTOR V / 19) and 2014 (CASTOR V / 52).
Container types
CASTOR type containers
| Technical specifications | CASTOR V / 19 | CASTOR V / 52 | CASTOR 440/84 | CASTOR HAW20 / 28CG | CASTOR HAW28M |
|---|---|---|---|---|---|
| Waste origin | Pressurized water reactor | Boiling water reactor | VVER -440 | Reprocessing plant | Reprocessing plant |
| Fuel element quantity | 19 BE | 52 BE | 84 BE | 28 glass canisters | 28 glass canisters |
| Length [mm] | 5,862 | 5,451 | 4,080 | 5,933 | 6.122 |
| Width (mm] | 2,436 | 2,436 | 2,660 | 2,480 | 2,430 |
| Mass [t] | 125.6 | 123.4 | 116 | 112 | 114 |
Similar containers from other manufacturers
The containers of other types listed here by the manufacturers "Excellox" (Great Britain) and "TN" (a trademark of Cogema Logistics , France) are listed here for the sake of completeness. The same basic principles apply to them. The term Castor is a synonym for all containers for the transport of radioactive substances (see also generic name ).
| Technical specifications | Excellox | TN 13/2 | TN 17/2 | TN 24 | TN 85 |
|---|---|---|---|---|---|
| Waste origin | Reprocessing plant | Pressurized water reactor | Boiling water reactor | Pressurized water reactor | Reprocessing plant |
| Fuel element quantity | 6 glass canisters | 12 BE | 17 BE | 24-37 BE | 28 glass canisters |
| Length [mm] | - | - | - | - | - |
| Width (mm] | - | - | - | - | - |
| Mass [t] | - | - | - | - | - |
literature
- N. Paech, E. Spoo, R. Butenschön (Eds.): Democracy - where and how? VSA-Verlag, Hamburg 2002.
- On the way to the nuclear state . Committee for Fundamental Rights and Democracy e. V., Cologne 2003.
- Thomas Oelschläger, Kerstin Enning, Bernd Drücke (Eds.): Ahaus. The book about the Castor . Klemm & Oelschläger Verlag, Ulm 1999, ISBN 3-932577-16-7 .
- 2.2.1.2 Shielding of ionizing radiation by the transport and storage container of the type CASTOR® V / 52. (pdf; 1.3 MB) In: Approval for the storage of nuclear fuels in the on-site interim storage facility in Brunsbüttel of the Brunsbüttel GmbH & Co. oHG nuclear power plant, Federal Office for Radiation Protection , November 28, 2003, pp. 92–94 , accessed on July 13 2016 .
Web links
- Manufacturer's website with videos on various experiments
Data
- Manufacturer GNS Gesellschaft für Nuklear-Service mbH
- Siempelkamp: CASTOR®, a high-tech product made of ductile cast iron (PDF; 15.2 MB), brochure from a supplier to the manufacturer
- Numbers and facts on nuclear fuel shipments. Federal Office for Radiation Protection , January 11, 2016, accessed on July 13, 2016 .
- Castor, a radiant train derstandard.at, November 5, 2010, thermal images
criticism
- www.bi-ahaus.de - Ahaus citizens' initiative against Castor transports
Individual evidence
- ↑ Dr. Wolfgang Steinwarz, Roland Hüggenberg, Prof. Ernst P. Warnke: CASTOR®, a high-tech product made of ductile cast iron. (PDF, 15 MB) Siempelkamp Nukleartechnik GmbH, accessed on January 10, 2020 .
- ↑ Federal Ministry for the Environment, Nature Conservation and Nuclear Safety: Safety requirements for the transport of radioactive substances ( Memento of the original from April 8, 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.
- ^ Castor: Top technology from Krefeld. In: wz-newsline.de. November 8, 2010, accessed November 8, 2010 .
- ↑ LS: 5. Change permit for the storage of nuclear fuels in the interim storage facility in Biblis of RWE Power AG. In: CASTOR V / 19 approval. Federal Office for Radiation Protection, September 22, 2015, accessed on January 10, 2020 .
- ↑ LS: 5. Change permit for the storage of nuclear fuels in the on-site interim storage facility in Philippsburg of EnBW Kernkraft GmbH. In: CASTOR V / 52 approval. Federal Office for Radiation Protection, February 24, 2016, accessed on January 10, 2020 .
- ↑ zeit.de: The legend of the salt dome. - At a loss in Gorleben: where is Castor really? The story of a self-deception
- ↑ Federal Ministry for the Environment, Nature Conservation and Nuclear Safety: Safety requirements for the transport of radioactive substances ( Memento of the original from April 8, 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.
- ↑ - GNS
- ^ Atomic Energy Act - § 4 Transport of Nuclear Fuels
- ^ Frankfurter Rundschau: Castoren before the last stage to Gorleben , November 28, 2011
- ↑ Overview of remaining transports ( memento of the original from January 29, 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.
- ↑ Delayed, missed, delayed. - The dismantling of the nuclear power plants is only making slow progress. Now it should be at the Konrad shaft. Nuclear opponents suspect a deliberate kidnapping , Die Zeit, March 14, 2012
- ↑ No bottleneck with CASTOR® casks - GNS. Retrieved June 19, 2019 .
- ↑ CASTOR® V / 52 receives approval under traffic law - GNS. Retrieved June 19, 2019 .
- ↑ message for change of name from Transnucléaire in Cogema Logistics
- ↑ THE TN 24 DUAL PURPOSE CASK FAMILY FOR SPENT FUEL: FACTUAL EXPERIENCE AND TRENDS FOR FUTURE DEVELOPMENT (English)
