The transport and storage cask CASTOR® MTR3 is specially designed for fuel elements from research reactors. It mainly consists of a ductile cast iron cask body, a fuel basket and a double lid system with metallic sealings. The sealings ensure leak tightness during transport as a Type B(U)F-package and during storage.

The cask has received its package design approval certificate  in January 2019. The first hot loading of a CASTOR® MTR3 with KKE7 fuel elements from the FRM II reactor (Munich, Germany) is planned for 2022.

Using individually customized fuel baskets the CASTOR® MTR3 is also able to accommodate fuel elements from different research reactors types such as MTR and TRIGA.