Bentonite for storage, conservation, decommissioning and disposal of radioactive waste (RAW)

Bentonite for storage, conservation, decommissioning and disposal of radioactive waste (RAW), spent nuclear fuel (SNF), nuclear and radiation hazardous facilities (NRHF)

In the nuclear industry, bentonite is used to create engineering barriers to isolate radioactive waste from the environment and ensure its safe disposal. It is used both in projects for the construction of new disposal facilities and to solve problems during decommissioning of nuclear legacy facilities, as well as for the conservation of various special RAW disposal sites. In addition, in operational RAW conditioning activities, bentonite is a small but important component in cement compound.

All RAW disposal and preservation projects at nuclear and radiation-hazardous facilities (NRHFs) apply the principle of multi-barrier protection with high requirements for waterproofing protection of structures against the ingress of surface or ground water to RAW packages over a long period of time. Bentonite fulfils this task to the maximum extent possible. This natural clay material has extremely low hydraulic conductivity and is able to retain the migration of a wide range of radionuclides. Its ability to swell provides hermetic sealing of insulation and a unique property of self-healing in case of barrier integrity failure.

To date, the Bentonite Group of Companies has accumulated considerable knowledge and technological experience to produce both compacted bentonite products of various geometries (blocks, segments, rings, etc.) and materials for buffer barriers, including high-density backfill. Since then, experience has been gained in laying bentonite in the underlying screens of near-surface disposal sites.

In addition, preparations for installation of external impervious screens at the nuclear legacy facilities in Seversk (JSC ‘SCC’) are actively underway. These will be the first facilities where it is planned to create vertical screens using the jet-grouting method in the ground at special RAW disposal facilities. Not only the technology, but also the material – BentInject® bentonite-based injection compound – is unique for the Russian nuclear industry.

Bentonite application in the nuclear industry:

1. Deep disposal of high-level radioactive waste – Zheleznogorsk, Krasnoyarsk Territory;
2. Near-surface disposal sites for medium and low-level waste – Novouralsk, Sverdlovsk Oblast (in operation); Seversk, Tomsk Oblast (under construction); Ozersk, Chelyabinsk Oblast (under construction); Saratov or Samara (in development);
3. Decommissioning of NRHF (Graphite Reactors, RBMKs, PWRs) by conservation for long-term storage;
4. Conservation of special RAW storage facilities (pulp and water reservoirs, solid RAW storage facilities, etc.);
5. LLW cementation facilities at APSs and chemical plants.