Reactor dismantling

Status: ongoing
Period: 2009-2028

The reactor building houses most of the site radioactivity. For this reason, dismantling operations of its components (systems, vessel and others) are more complex to carry out.

Some dismantling preliminary activities have been already implemented.

The reactor building houses the primary system, namely the main four circuits that transfer heat from the reactor to turbines. Between 2003 and 2004, decontamination of the steam generators of the circuits reduced 100 times their activity levels. Between 2005 and 2008, asbestos was removed from pipes, pressure systems and steam generators of the reactor building.

Between 2009 and 2013, the ventilation system was re-adapted to make it more suitable for decommissioning operations. In the same period, the access routes to the container were restored to ease the handling of materials and the movement of people in the dismantling stage.

Between 2013 and 2017, non-contaminated components of the reactor were removed, resulting in approx. 200 tonnes of iron to be sent to a recovery facility after radiological tests. The operations presented some difficult aspects, related to the cutting of materials in narrow spaces and handling on the different floors of the building.
Before decommissioning the reactor radioactive components, the plant must be radiologically evaluated. In fact, between 2016 and 2017, 60 metallic samplings were sent to radio-chemical analysis (each test lasts approx. one month).

In 2015, decommissioning activities were initiated; they included removing the fuel loading crane, the anti-missile shield, the asbestos materials on the top of the vessel and other components that interfered with the opening of the vessel.

All auxiliary systems for carrying out the vessel opening (bridge crane, tank circulation systems, water accumulation systems) were reactivated. These activities also included replacing the devices to monitor the reactor cavity, verifying sealings and replacing obsolete components.
The tendering design procedures for the dismantling of primary circuit are now under development. The first stage will involve the radiological characterisation of vessel and internals. Upon completion of this activity, the cap of the vessel and upper part of the reactor (upper package) will be dismantled (Stage 2). The removal of the activate internals and the cylindrical structure will be subsequently carried out (Stage 3).

In parallel with the vessel operations, the dismantling of primary circuit will be implemented. The first stage will involve the vessel insulation. Subsequently, primary pumps, circuits and auxiliary systems will be dismantled. The third stage will involve the dismantling of large components (pressure system and steam generators). The complexity of this work is connected both to the size of components and to the concurrent performance of the dismantling operations for the vessel.​​