The ISFS facility is a modular vault type facility designed for the storage of spent nuclear fuels. The store is a surface facility, in which the fuel assemblies are each stored in vertically installed airtight sealed heavy storage tubes. The tubes are inserted into vaults enclosed with concrete walls. Adequate shielding is provided by the concrete structure of the vaults around the storage tubes. Each vault comprises 450 storage tubes.

The storage takes place in dry conditions and the generated remnant heat is removed by a cooling system based on natural air draught. This ensures that no electrical fault or technical problem could result in loss of cooling. The filtered cooling air flows through the interspace among the storage tubes and can not get in contact with the fuel assemblies. Inert gas (nitrogen) atmosphere is provided in the storage tubes.

The reception building, which is a structurally independent unit, is situated next to the first storage module. This part of the ISFS facility comprises the items of equipment and systems required for transfer cask and fuel handling operations to be performed prior to loading the fuels into the storage tubes.

The supply and process system rooms, the ventilation systems, the sanitary equipment for the operation personnel and the control systems are installed into the reception building.

In addition to the radiological and coolability considerations, the effects of the seismic events and the protection against high ground water level were also considered in the design of the facility. The datum level of the ISFS facility was specified to ensure that the facility can not be flooded even in the case if the maximum design flood level occurs. A site seismicity characterised by an earthquake recurrence frequency of 10000 years and a horizontal acceleration of 0.25 g was specified by the licensing authority for consideration as typical to the site. The alarm systems of the ISFS are aligned to the similar systems of the power plant.

The ISFS site is within the flight-ban zone of Paks Nuclear Power Plant, ranging over an area with a diameter of 3 km and an altitude of 7000 feet (2133 m).