Nuclear: 23 Million project for safe radioactive waste management

Developing innovative radioactive waste management solutions is the goal of the European project PREDIS^[1], funded with more than 23 million euro by the Horizon 2020 program, which comprised 47 partners from 17 countries, including seven from Italy: ENEA, Istituto nazionale di fisica nucleare (INFN), Ansaldo nucleare, Nucleco, Sogin, Politecnico di Milano and University of Pisa.

In particular, the project PREDIS aims at improving the characterization, treatment and conditioning of low and intermediate level radioactive waste for which technologically mature solutions are not yet available (metallic materials, liquid and solid organic waste). As part of the project, digital innovations to support decision-making have also been developed and, awaiting implementation of national repositories, solutions for temporary storage of radioactive waste already immobilized with cement have been tested.

At ENEA, the activities of its Nuclear Department^[2] have focused mainly on the treatment and conditioning of liquid organic waste, one of the seven lines of action of the project.

 “Maintaining radioactive liquid organic waste into a solid and stable form for long periods of time is difficult due to chemical issues. Instead, thanks to geopolymers which enable to create cement-like materials, we have formulated matrices that provide excellent potential performance both in terms of organic liquid incorporation and robustness and durability over time,” explained project leader Giuseppe Augusto Marzo at the ENEA Nuclear Department.

In addition, researchers Maria Letizia Cozzella, Tiziana Guarcini and Fabio Girardi at the ENEA Radiological Characterization Laboratory used blast furnace waste materials to demonstrate that safer final forms of radioactive waste can be achieved in storage, transport and disposal. The experimental activity was conducted in collaboration with the subsidiary company Nucleco.

 “We tested the sample of material to exclude percolation of soluble elements incorporated within the matrix and to assess its stability. New formulations based on geopolymers made from blast furnace slag enabled to incorporate organic liquids up to 30 percent by volume and showed significant compressive strength, a necessary condition for these matrices to be adopted for actual use,” said Marzo.

The PREDIS research activities will continue with EURAD-2^[3], the second phase of the European research program that assists EU countries in implementing Directive 2011/70/Euratom on radioactive waste management. At this step, national research and development programs will be integrated by involving waste management organizations, technical support organizations and research institutions.

ENEA has been authorized by the Ministry of the Environment and Energy Security to participate in EURAD-2 as representative for Italy. As part of the project, the Nuclear Department will study innovative techniques for the physicochemical-radiological characterization of radioactive waste, develop new matrices to make radioactive waste inert and conduct geological-environmental research to support disposal.