A device for storage of hazardous material, especially heat-producing hazardous material, such as radioactive spent nuclear reactor fuel, comprises a substantially cylindrical reinforced concrete body  and has an axially elongate storage space  for the hazardous material. A prestressed reinforcement having reinforcing members  extending helically about the storage space  is provided in the concrete body adjacent to the outer side thereof. Preferably, the reinforcing members  are divided into two groups, one inside the other, the hand of the reinforcing members  of one of the groups being opposite to the hand of the reinforcing members  of the other group. Also preferably, the ends of the concrete body are provided with end covers  in which the reinforcing members are anchored.

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