ASN Report 2017

315 ASN report on the state of nuclear safety and radiation protection in France in 2017 Chapter 11  - Transport of radioactive substances industrial packages. Three sub-categories of industrial packages exist according to the risk presented by the content. Depending on their sub-category, the industrial packages are subjected to the same tests as type A packages, some of the tests or only the general provisions applicable to excepted packages. As a result of the restrictions on the authorised contents, the consequences of destruction of a type A package or an industrial package would remain manageable, provided that appropriate emergency management measures are taken. The regulations do not therefore require that this type of package be able to withstand a severe accident. Due to the limited safety issues, type A and industrial packages are not subject to ASN approval: the design of the packages and the performance of the tests are the responsibility of the manufacturer. These packages and their safety demonstration files are subject to spot checks during the ASN inspections. 2.3.3 Type B packages and packages containing fissile substances Type B packages are those used to transport the most radioactive substances, such as spent fuel or vitrified high-level nuclear waste. The packages containing fissile substances are industrial, type A or B packages, which are also designed to carry materials containing uranium-235 or plutonium and which can thus lead to the start of an uncontrolled nuclear chain reaction. These packages are essentially for the nuclear industry. Gamma radiography devices also fall into the type B package category. Given the high level of risk presented by these packages, the regulations require that they must be designed so that, including in the case of a severe transport accident, they maintain their ability to confine the radioactive material and ensure radiological protection (for type B packages) as well as sub-criticality 2 (for packages containing fissile materials). The accident conditions are simulated by the following tests: ཛྷ ཛྷ A 9m drop test onto an unyielding target. The fact that the target is unyielding means that all the energy from the fall is absorbed by the package, which is highly penalising. If a heavy package actually falls onto real ground, the ground will deform and thus absorb a part of the energy. A 9m drop onto an unyielding target can thus correspond to a fall from a far greater height onto real ground. This test can also be used to simulate the case of the vehicle striking an obstacle. During the 9m free-fall test, the package reaches the target at about 50 km/h. However, this corresponds to a real impact at far greater speed, because in reality, the vehicle and obstacle would both absorb a part of the energy. ཛྷ ཛྷ A penetration test: the package is released from a height of 1m onto a metal spike. The aim is to simulate the package being damaged by perforating objects (for example debris torn off a vehicle in the event of an accident). ཛྷ ཛྷ A fire test at 800°C for 30 minutes. This test simulates the fact that the vehicle can catch fire after an accident. ཛྷ ཛྷ An immersion test under 15m of water for 8 hours. This test is used to verify the pressure-resistance if the package were to fall into water (river by the side of the road or port during offloading from a ship). Certain type B packages must also undergo a more severe immersion test, which involves immersion under 200m of water for one hour. 2 . www.asn.fr/Informer/Actualites/Enquete-de-l-ASN-sur-les-flux-de-transport- de-substances-radioactives (ASN survey on radioactive substances traffic) Areva TN81 transport packaging.