Konrad transport study: safety analysis of the transport of radioactive waste to the Konrad waste disposal site

A safety analysis has been conducted for the transport of non-heat-generating (low- to medium level) radioactive waste to the planned Konrad final repository in Germany. The results of the risk analysis show that it is unlikely that transport accidents with a release of radioactive substances will occur in the region of the final repository during the operating period of approximately 40 years. Because of the lower accident risk of transport by rail as compared with road, the envisaged high fraction of rail transport of the entire transport volume has a beneficial effect. In the case of an accident with a release of radioactive substances, the potential radiological consequences, in general, decrease rapidly with distance; starting from around 250 m by a factor of 10 up to about 1200 m and a further factor of 10 at a distance of about 6200 m. The releases associated with accidents are frequently so small that the potential radiation exposure, even without countermeasures, is below the natural radiation exposure for one year, at a distance of about 250 m from the accident location: this is true for 9 out of 10 accidents with goods trains and 19 out of 20 accidents with trucks. With the hypothetical assumption of continuous operation of the repository, a potential effective dose of 50 mSv without countermeasures would result, on average, once every 500,000 years at a distance of 250 m in the direction of atmospheric dispersion for the scenario 100% rail transport and once every 400,000 years for the scenario 80% rail/20% road. 50 mSv corresponds to the design guideline exposure of 28 Para. 3 of the German Radiological Protection Ordinance and the annual dose limit for persons occupationally exposed to radiation. The expected frequencies of corresponding accident consequences are considerably lower for the Braunschweig marshalling yard. It can thus be concluded that waste transport does not pose any major additional risk to the region of the repository. (author)