Dry cask storage

CASTOR ( cask for storage and transport engl. of radioactive material " container for storage and transport of radioactive material " ) is an internationally registered brand name of the Society for Nuclear Service ( GNS ).

Castor containers are special containers for storage and transport of highly radioactive materials such as spent fuel from nuclear power plants or waste products ( " vitrified " ) from reprocessing.

In general, the German language is " castor " used as a synonym or generic name for fuel element container or containers of highly radioactive waste.

• 3.1 Test method
• 3.2 Other scenarios
• 3.3 terrorist attacks
• 3.4 jurisprudence

• 6.1 container of the type CASTOR
• 6.2 Similar container from other manufacturers

• 8.1 Data
• 8.2 criticism

Manner of construction

The transport and storage container has a total gross weight of 110-125 tons. It consists essentially of a thick-walled cylindrical container body made ​​of ductile iron or forged steel and a double lid - sealing system. The sealing cap is screwed to the container body and provided with long-term resistant metal seals. Are axially or radially cooling fins for passive decay heat removal heat ( this is needed for every radioactive decay ) to the outer surface. For transporting soil and cover side shock absorber to mitigate any accidental shock loads are attached.

The types CASTOR V/19 today for Transport and interim storage of spent fuel usually ( for 19 fuel from pressurized water reactors ) or CASTOR V/52 used ( for 52 fuel assemblies from boiling water reactors ). Both types can hold about 10 tons of cargo. The site interim storage included in their permits for these containers a maximum allowable surface dose rate of 0.35 mSv / h, of which a maximum of 0.25 mSv / h may be caused by neutron radiation (ie, a one-hour stay leads immediately adjacent to the container to a dose of about 0.35 mSv, which corresponds to about one -seventh of the normal annual radiation exposure of the population of 2.5 mSv ). The containers are certified to the interim storage permits for the inclusion of a maximum of 180 kg Heavy metal and an activity inventory of a maximum of 1.2 · 1018 Bq. Already returned highly radioactive vitrified waste from reprocessing have been transported and stored in containers of the type CASTOR HAW 20/28 CG. The containers referred to are about 6 m long and have a diameter of about 2.50 m, the wall is 45 cm thick. When loaded, the containers have a mass of up to 117 tons. Main component of the Castor containers is cast iron with spheroidal graphite ( GGG40 ).

(2003 ) for further storage, it is intended to open the container and rearrange the waste into Pollux container.

In 2008 came for the transport of vitrified waste from reprocessing in France container type TN 85 used. In 2010, a new type of container CASTOR HAW28M were used for the first time. These containers can dissipate a heat output of 56 kW.

The safety and suitability of castor and other storage and transport containers for radioactive material is regularly debated even at the international symposium PATRAM.

A Castor containers cost around 1.5 million euros.

Security regulations in Germany

Legal basis

The Atomic Energy Act regulates in Germany, inter alia, the handling of nuclear fuel and hence the management of spent fuel. According to § 4 of the Atomic Energy Act require their transport and their storage in accordance with § 6 of a permit by the Federal Office for Radiation Protection ( BfS).

The authorization of the transport and storage containers made ​​by the Federal Office for Radiation Protection (BfS ). As a reviewer BfS the Federal Institute for Materials Research and Testing (BAM ). As part of the approval are from the manufacturers test results and evidence to be provided.

The transport of heat-generating waste (eg glass canisters ) must also be applied at the BfS and approved by this.

Type B packaging

Castor containers are so-called Type B packaging and furthermore satisfy the acceptance criteria of centralized and decentralized transport container camp in Germany. For Type B packaging a type approval is required in accordance with traffic law, is responsible for the in Germany, the Federal Office for Radiation Protection ( BfS).

Type B packaging must all occur during normal transportation and possible severe transport accidents mechanical and thermal loads. Your safety functions may not be significantly affected even in a severe accident, so that no radioactive substances from the packaging can be released into the environment. The Federal Institute for Materials Research and Testing (BAM ) tests as an expert on behalf of BfS the mechanical and thermal properties of the packages. As part of the approval are from the manufacturers test results and evidence to be provided.

The requirements for the Castor containers comply in Germany with the recommendations of the International Atomic Energy Agency ( IAEA). Container would then resist following accident scenarios:

To demonstrate the computational proof or test of a ( scale ) model is sufficient. The first three accident scenarios could be performed sequentially on the same model. The container must not remain completely undamaged, but the shielding effect of the container may not worsen the burden by up to a factor of 100 ( 10 mSv / h ( millisieverts per hour at 1 m ) ). The case of 9 m in height results in that the speed of the container upon impact with the surface of about 48 km / h.

In addition to the tests prescribed more are performed. So for example:

• Fall of a container from a motorway bridge height of 40 meters,
• Fall of a by -cooled to -40 ° C container height of 9 m,
• Explosion of an LPG tank truck with 5 tons of propane right next to a container,
• Fire test at 1200 ° C for 30 min,
• Dropping a container to scale from a helicopter 800 m altitude,
• Direct impact of a passenger train, with 130 km / h, the longitudinal side of a container,
• Bombardment of a container with a 1000 kg replica of an aircraft turbine shaft 292 m / sec (1050 km / h).

The manufacturer indicates that the vessel had suffered by these tests, no impairment of safety functions and have remained pressure-tight.

Criticism of the security

Test method

Critics doubt the validity of the tests, test series and projections for the safety of various Castor containers or appropriate container. For earlier tests, empty containers were used, they were therefore somewhat easier than in the case of application. In the meantime, come in drop tests simulated inventories are used, which correspond to the original inventory in their dimensions and mechanical properties. Many experiments were conducted with scale models in a scale of 1:2, the static approximates the originals. Critics compare this with a crash test of cars, in which no one would rely on miniature experiments.

Finally, a long time has been dispensed with entirely different tests alone and instead resorted to theoretical calculations. Once in July 2002 by independent observers computational errors have been named in the assessment of fall to a concrete floor, new calculations were carried out, which until December 2005 closure.

The approval is sought only for newly developed container. For variations of once tested containers no new approval procedures are performed by default, for example, if another insert basket used or a completely different shock absorber ( end cap ) will be used.

Other scenarios

In addition to this general skepticism there are also concrete criticism of the prescribed test procedures.

• The heat test covers some scenarios not realistic from when about larger amounts of combustible material involved in an accident. In a collision with a tanker truck, especially in a tunnel, it is likely that temperatures in excess of the intended 800 ° C may occur and the fire lasts longer than half an hour. (Example: 1999 lasted triggered by a burning truck in the Mont Blanc tunnel fire over 50 hours).

Terrorist attacks

Was left at the security target completely ignores the possible wanton destruction of container, such as terrorist attacks. For terrorists, the Castor transports hundreds of kilometers and several countries are a much easier target than the relatively well-secured in relation to nuclear power plants. For this reason, it was officially banned in France, to announce the transport routes. In Germany the transport routes are not already published.

Court

Courts saw in these arguments never a reason to doubt the safety of the vessels used. The critics failed in all court proceedings. The judges regularly followed the arguments of the reviewers of the approval authorities and confirmed the legality of the interim storage or use of the containers used.

Transport of Castor containers to and within Germany

Castor containers are mostly transported as freight. Road transport generally take place where there is no railway facilities exist, such as in the final kilometers between the loading crane in Dannenberg (Elbe ) and the transport container storage facility. In Germany, the spent fuel from the nuclear power plants have been set to the reprocessing plant on 30 June 2005 due to the nuclear phase transport; instead, used the Castor containers as temporary storage, which are often located at the respective power plant sites. The present in the reprocessing plants at La Hague nuclear fuel from German nuclear power plants were transported to November 2011 in the Gorleben interim storage facility. In the years 2014-2017 the fuel from the Sellafield are to follow in Germany prevails in large parts of the population resistance to the transport of highly radioactive waste. The largest protests regularly cause the repatriation of reprocessed fuel rods from the reprocessing plant of La Hague in France to the Gorleben interim storage facility. At demonstrations and sit-ins to participate regularly several thousand people. Locally Lüchow- Dannenberg, there is a strong tradition of protest enshrined with trained infrastructure. Also along the transport path in Germany there are regular protests and blockades.

The criticism of opponents directed not against the return of the German nuclear waste to Germany. This also shows the involvement of French environmental activists in the blockades along the transport path and the Wendland. The protests turn generally against the continued production of additional nuclear waste in the current nuclear power plants, and most especially against the Gorleben repository site that is considered unsuitable and dangerous. Not only the local population fears that the political decision for the final repository is strengthened by the transports to transport container storage facility. In contrast, decentralized storage shorten at the power plant sites the transports in the temporary storage and are no preliminary decision for a particular repository site.

2011, the Federal German government after the Fukushima nuclear disaster a nuclear phase-out. Eight of the 17 German nuclear reactors were shut down.

In Germany only makes the Society of Nuclear service Castor containers. However, it can not satisfy the market demand for years. The operators of nuclear power plants can then begin at the earliest with the dismantling, if the fuel rods are removed from the reactors and spent in Castor:

"At the moment the GNS can not deliver the coveted Castor; at least the one guy who just needed urgently. For him, the GNS still needs approval from regulatory authorities that will surely not come this year. With the nuclear phase-out the Castor are scarce - so scarce that the nuclear companies negotiate partially, particularly those who urgently needs a container, and who can wait. Alone Vattenfall missing after information of the Ministry of Justice in the Nuclear Brunsbuttel so many Castor that once only ten percent of the reactor core can be outsourced. At least 465 fuel elements must initially remain in the nuclear power plant. As long as they are in the reactor pressure vessel, the demolition may not begin. "

Container types

Container of the type CASTOR

Similar container from other manufacturers

All listed container of a different design, the manufacturer " Excellox " ( Great Britain) and "TN" ( a trademark of Cogema Logistics, France) are listed here for completeness. For them, the same basic principles apply. The term Castor is a synonym for all container for transport of radioactive material (see also species name).