Remediation of Pit 7.1, completed the removal of the monolith

18 December 2019

​Today, at Itrec plant in Rotondella (Matera), Sogin concluded the removal of the "monolith" in reinforced concrete containing radioactive waste, present in Pit 7.1.

The engineering solution adopted by Sogin, drawn up with Italian know-how, is unprecedented at an international level and will lead to a significant step forward in the decommissioning of the Lucan nuclear site.

Built in the late 1960s, the monolith is a vertical structure of a prismatic shape with a mass of about 130 tons and a volume of 54 cubic meters. It is located 6.5 meters deep from the ground level and inside, divided into four square-section wells, there are drums with medium-radioactive waste, incorporated in cement mortar and deriving from the operation of the plant.

The lifting and extraction of the individual wells is the last phase of the works that will allow the remediation of the area of Pit 7.1. The four wells removed were totally-safely transferred to a deposit for their temporary storage.

The first phase of the work involved a series of preparatory activities such as the construction of the hydraulic barrier, the construction of a special cover for the static and dynamic containment of the area, the excavation around the monolith and its consolidation. Furthermore, some necessary investigations were carried out to define the positioning of the drums in the four wells and, thus, the liquids were drained.

Before starting the removal operations, the monolith was stabilised with especially designed metal structures and capsulated within a special steel structure.

Then, the structure was cut horizontally, by drilling the base of the structure using a core drill, and vertically, from top to bottom, by using a diamond wire, so as to separate the four wells from each other. Finally, in order to enable its removal, specific lifting systems have been installed, dimensioned to support each single well which, complete with steel containers, weighs about 45 tons.

All the activities performed by Sogin are authorised and supervised by local and national Authorities and Bodies, responsible for supervising and monitoring the decommissioning and the securing of radioactive waste in the plants.