Press Note - Sogin finished the backfill works of Pit 7.1

27 July 2021

Sogin has finished the backfilling of Pit 7.1 at the ITREC site of Rotondella.

With these works, Sogin completes the remediation of the area inside which there was the reinforced concrete "monolith", divided into four square section pits containing radioactive waste produced during the operation of the plant, removed by Sogin in December 2019 with an engineering solution unprecedented at international level.

The backfill works had started on 23 June, after completing the characterization activities, removing the shed that protected the site area and the instrumentation used for the remediation works, and decommissioning the P7.1 well, used in the past to drain groundwater and prevent it from coming into contact with the structure of the monolith buried inside Pit 7.1.

The backfill, for which about 600 cubic meters of fill material was used, was carried out in four phases. In the first one, a layer of non-woven geotextile was laid on the bottom of the area and then the pit was gradually filled with the first layer of river or quarry pebbles. Then the second layer was made with the compaction of stabilized mixed material to finish filling the pit with pozzolan. During all phases, load tests were carried out on plates to verify the capacity of the soil.

At the same time as the backfilling activities, several core drillings were carried out to reconstitute the hydraulic continuity of the aquifer underlying the site.

On the area the Process Building of the Finished Product Cementation Plant (ICPF) will be built, which will allow to cement the uranium-thorium liquid solution, called "finished product", produced during the experimental activities carried out in the ITREC plant during its operation, in view of its subsequent transfer to the National Repository, when available.