Container for direct ultimate waste disposal of spent fuel elements. Naming relates to Castor® (transport and interim storage container for spent fuel elements) after the twin brothers Castor and Pollux of the Greek legend. The concept of direct ultimate waste disposal provides that spent fuel elements be compacted, packaged in tightly closed containers and safely stored in repositories isolated from the biosphere. For reference test, a container with a design of the “Pollux” type has been developed which can hold up to eight pressurized water reactor fuel elements. It has a diameter of about 1.5 m, a length of approx. 5.5 m and a weight of 64 tonnes when loaded. The container is equipped with a double shell and ensures the safe inclusion of radionuclides. An internal container to accommodate the compacted fuel elements – separated by a neutron moderator – is surrounded and protected by an external shield container made of spheroidal graphite (SG) iron. The Pollux container system is designed in compliance with the traffic law regulations for type B(U) packings and the atomic energy law for interim storage of nuclear fuel. The containers can therefore be used as transport, interim storage and ultimate waste containers.