The first of five containers for used fuel that are planned to be stored in the Garoña Individualised Temporary Warehouse (Aeroparque Tecnológico Industrial – ATI) were put in place on 7 July, in accordance with the Spent Fuel Management Plan (PGCG) of Santa María de Garoña NPP, recently approved by the Ministry for the Ecological Transition and Demographic Challenge, following a favourable report from the Nuclear Safety Council (CSN).

The Garoña NPP, which began operation in 1971, was Spain’s oldest nuclear plant. It ceased operation in 2012 when owner-operator, Nuclenor (a joint venture of Endesa and Iberdrola), objected to a new tax. Although it had a permit until 2019, it was formally closed down in 2017. Decommissioning company Enresa expects to complete phase 1 of its dismantling in 2023.

The transfer of the used fuel to the ATI was directed Nuclenor and supervised by CSN. The operation took more than 160 hours and included preparation of the container, its transfer to the used fuel pool, the loading of the 52 used fuel rods and their transfer to the ATI.

The 71-ton container, manufactured by Spanish company Equipos Nucleares SA (Ensa), has a height of 4.85 metres, a diameter of 2.1 metres. In the course of the operation the planned process was revised to accommodate a change of fuel handling tool. This was communicated by Nuclenor to the CSN, as it is considered relevant both for future loading processes in Garoña, as well as for the exchange of operating experience with other plants.

The Santa María de Garoña NPP’s ATI is an outdoor facility located inside plant site. Its main function is to guarantee the safe and stable storage of used fuel from the pool and special waste from the operation and dismantling of the facility itself. It mainly consists of two seismic slabs on which the dry storage containers can be stored.

Over the next few months, the loading and subsequent transfer to the Garoña ATI of the other four containers will continue.

Subsequently, as part of the first phase of the dismantling of the NPP by Enresa, and in accordance with the PGCG, the remaining 2,245 fuel elements in the pool will be removed from the pool using 44 additional containers, which are currently in the manufacturing process. 

The ENUN 52B containers were specifically designed to meet the needs of the Santa María de Garoña NPP, and can hold 52 boiling water reactor fuel assemblies. It is made up of a forged carbon steel body surrounded by a polymer that acts as a neutron shield, with two bolted covers and a frame made of a material composed of a neutron absorber and stainless steel plates. The container was first approved for storage by the CSN (Nuclear Safety Council) in November 2014 and for transport in June 2015.

Image: The first container for used fuel in place at Garoña's Aeroparque Tecnológico Industrial (photo courtesy of Enresa)