We take you inside the Garigliano nuclear power plant

The decommissioning of the Garigliano nuclear power plant is entering its final stages and by 2035 Sogin should finish dismantling the Sessa Aurunca plant. We entered the plant, which is located between Campania and lower …

We take you inside the Garigliano nuclear power plant

The decommissioning of the Garigliano nuclear power plant is entering its final stages and by 2035 Sogin should finish dismantling the Sessa Aurunca plant. We entered the plant, which is located between Campania and lower Lazio (the protection zone is approximately 120 hectares): around the Caserta power station there are almost no radiation levels, between 0.2 and 0.7 microsievert/hour inside the sphere that houses the vessel.

Built between 1958 and 1963 by Senn (National Electronuclear Company), the Garigliano nuclear power plant is based on the project by Riccardo Morandi (the same designer who returned to the limelight for the collapse of the bridge of the same name in Genoa in August 2018) . In 1964 the plant went into operation. The power plant, of the BWR (Boiling Water Reactor) model, belongs to the first generation of nuclear plants, with an electrical production power of 160 MWe. Its reactor was the first BWR built in Europe. In 1965, ownership of the power plant was assumed by Enel which used the plant until 1978, when it was stopped for maintenance, before being definitively blocked in 1982 and shut down in 1986. In 1999 the power plant was acquired by Sogin , the public company that deals with the decommissioning of Italian nuclear plants and the management of radioactive waste, which began the decommissioning of the plant in 2012.

The Garigliano nuclear power plant came into operation in 1964

Our tour starts from the maneuvering room where the management of the plant took place. A 'suspended' staircase leads to the rooms where, next to the new panels in operation for the ongoing dismantling activities, there are the panels and the desk, with cranks and buttons for managing the power plant, which were there when the The plant was in operation. A technology that is dated and yet gives the impression of being in a science fiction film. In the horseshoe-shaped room, among the various components, the vessel's monitoring and management panel stands out, inside which there were 208 fuel elements, containing enriched uranium (238 and 235), in addition to the control rods and safety.

There were two measures that allowed the plant to stop in case of critical issues: one with the control bars that entered the vessel from below, the other involved the pouring of “liquid poison”, i.e. boric acid which was injected to capture neutrons. What is striking is the total absence of digital tools at the time with workers making their decisions based on mathematical calculations carried out “by hand”. “Highly specialized and trained people worked there”, explain the Sogin employees who accompanied us during the visit.

The maneuvering room in the Garigliano nuclear power plant

From the maneuvering room, through a corridor, you pass to the rooms that house the reactor. The large sphere has a diameter of approximately 48 meters and a thickness of approximately 3 centimeters of steel. Here the nuclear reaction actually took place. The rooms are completely isolated both statically (through lead doors) and with a ventilation system that uses decompression and prevents air from escaping in the event of leaks. The spherical shape was chosen for two reasons: one because it was able to react better to impact in the event of an explosion, the other was aesthetic: “it softens the visual impact”.

The swimming pool of the vessel of the Garigliano nuclear power plant

Inside the sphere is the vessel. In December 2023 the head of the vessel was removed and the internal components, called internals, and the metal control bars are now being disposed of. The operations take place in a sort of swimming pool, the so-called “reactor channel”, with the water acting as a shield against radiation, guaranteeing safety also for the operators. Inside the radiation level is that of the 'ambient background', between 0.2 and 0.7 microsieverts/hour.

“All activities are carried out remotely through robotic systems – explains Luca Savino, Sogin's decommissioning manager for the Garigliano power plant – The components are gradually removed and inserted into metal containers to be stored in temporary warehouses (the Caserta power plant hosts some currently three, ed) waiting to be transferred to the national deposit that will be built”, and whose construction Sogin itself will take care of. At the moment decommissioning has reached 67 percent but the operations underway inside the reactor building occupy a further 15 % of assets: “The end of operations is scheduled for 2035,” adds Savino.

The radiation level inside the reactor building

Most of the materials are recovered. “Of a total of 270 thousand tons, only 6 thousand are radioactive waste with an enormous reduction in waste management costs”, says the 'chief' Savino. It must be said that in addition to management costs, external procurement has an impact of 390 million euros.

6 thousand tons of radioactive waste out of 270 thousand total

But how does recovery happen? In the turbine building, the so-called Waste Management Facility (WMF) was set up by Nucleco – a subsidiary of Sogin – inside which the various “pieces” of the plant – approximately 400 kg at a time – are treated with sand until the complete removal of contaminated elements. Another way to eliminate 'radioactive' parts is to merge them with waste which is sent to the Swedish plant of Cyclife Sweden AB, where the non-contaminated parts – which are recovered for reuse – are separated from the contaminated ones. About a tenth of the quantity sent, in the form of “ingots”, returns to the plant where it is stored in temporary warehouses. “An example of our concrete commitment to supporting the circular economy to be reused. In some cases it is also sold”, says Savino again.

'Sandblasting' to eliminate radioactive waste from the various components

After the completion of the decommissioning operations, the structure of the nuclear power plant will not be demolished. The sphere building and the one that housed the turbines will remain as industrial architectural heritage. “When the decommissioning began – explains Savino – there was a constraint not to demolish the two main buildings”. At the moment, however, a clear final destination has not been decided for reusing the structures that will remain of the plant.

The Garigliano nuclear power plant will not be demolished after decommissioning

The external environmental impact, however, is “radiologically irrelevant”. Sogin manages a complex environmental surveillance network and monitors, with continuous and scheduled checks, the quality of the air, the soil, the surface and underground waters, the fish products of the Garigliano and the nearby coast, as well as the main agri-food products of the territory: milk, fruit and vegetables. The environmental surveillance network, established, as for other nuclear sites, at the time of construction, has never stopped. Every year Sogin carries out hundreds of measurements on these matrices while Arpa Campania carries out a similar monitoring and surveillance activity with its own network. The results of analyzes have always confirmed environmental impacts that are radiologically irrelevant. The monitoring results are sent to the Isin Control Authority and made public.