The SOCRATES project addresses critical gaps in our understanding of the liquid source term during severe nuclear accidents and offers innovative solutions to mitigate and monitor the release of radionuclides into the environment. The project contributes to the mid-to-long-term management of nuclear power plants after a severe accident by enhancing safety, environmental protection, safe waste management and public well-being.

SOCRATES is composed of three major parts:

1) Reviewing the current knowledge on the liquid source term phenomena in severe NPP accident context,

2) Experimental research on the evolution of liquid phase chemistry, fuel debris leaching, innovative absorbent materials for radionuclides, and miniature size radiochemical laboratory,

3) Defining the key chemical processes for Cs, Sr and U in sump and mathematical models.

• Comprehensive State-of-the-Art Report. SOCRATES will review the current understanding of the liquid source term in SA, with emphasis on evaluating the capabilities of existing accident analysis codes (e.g. predict chemical speciation in the liquid phase, both in soluble and insoluble forms). The report will set this baseline and will add on the project results in every respect that is being investigated.
• Experimental database. SOCRATES is building a database on water chemistry during nuclear accidents by cataloging potential materials (e.g. concrete, paint, metals) that could interact in different accident scenarios. Experiments will place major emphasis in investigating: specific fission products behavior, such as cesium (Cs) and strontium (Sr), in water; fuel debris leaching, including tests with real corium samples. This database will support the development of computer models.
• New computer code models. SOCRATES will develop computer code models capable of predicting and managing the potential release of radioactive materials in liquid form during severe nuclear power plant accidents. Different scenarios are to be addressed involving fission products behaviour in aqueous environments during SA. In the end, the intention is to validate the models developed and integrate them into European safety analysis codes (e.g. ASTEC, AC2) supporting further accident management actions.
• Innovative Absorbent Materials. Mitigating the release of radioactive materials in liquid form during severe accidents requires innovative and effective clean-up technologies. Promising absorbents are being identified (e.g. zeolites, clays, MOFs, and silicas) and their performance is planned to be demonstrated, including their own synthesis.
• Innovative Miniature Size Radiochemical Laboratory. A novel miniature size radiochemical laboratory (the size of a credit card) is being developed in SOCRATES to allow the early measurement of radionuclides of interest, e.g. Cs and Sr.

Novel database and computer code models on liquid source term phenomena will be developed. Innovative absorbent materials and miniature-size radiochemical laboratory for radionuclides will be developed. Besides the research activities, SOCRATES results communication, dissemination and exploitation is crucial. It includes for example preparation of scientific publications, researcher mobilities and preparation of educational materials.

VTT, ASNR, CEA, Chalmers, CIEMAT, EDF, ETH, Framatome, GRS, JRC, KTH, KU, NUVIA, PSI, RUB PSS, SSTC NRS, UL

October 2024 to September 2028 – 4 years

Budget € 5 455 558,00

Technical Project Leader:

Teemu Kärkelä (VTT)

Email: teemu.karkela@vtt.fi

This project has received funding from the HORIZON-EURATOM-2023-NRT-01 under grant agreement No 101163745.