FAST/Advanced Nuclear Systems Group: Generation-IV nuclear reactors with a fast neutron spectrum

Molten Salt Reactor Workshop at PSI on December 10, 2025.

PSI as a signatory of the Generation IV International Forum is involved in a collaboration on fourth generation nuclear systems development and will host in December the GIF MSR (Molten Salt Reactor) project meeting. At this occasion, LSM will organize a Molten Salt Reactor workshop. Different national programs of GIF member states will be presented inclusive the Swiss activities on 10. December from 9:00 to 13:00 in the PSI auditorium. Interested PSI scientists are welcome to participate.

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Interested PSI scientists are welcome to participate. For in person participants no registration is needed, for online participants, please register here to obtain the workshop link: Register.

We launched the project in 2002 and our current goals are:

to study neutronics and nucleonics, thermal hydraulics and fuel behaviour of advanced fast-spectrum nuclear reactors using modern computational tools: TRACE/PARCS/FRED, Eranos/EQL3D, Serpent 2, OpenFOAM;
to evaluate safety of fast reactors developed in Europe, in particular, European Sodium Fast Reactor (ESFR);
to analyse innovative design solutions for Generation-IV Molten Salt Reactor;
to represent Switzerland internationally at GIF, IAEA, OECD, EURATOM;
to educate young researchers and students, in particular, via the ETHZ/EPFL Master of Science in Nuclear Engineering and EPFL PhD programs.

August 28, 2025

In August 2025 Julia Swiatkowska was selected by swissnuclear for the PhD grant. Ms. Swiatkowska should evaluate two or more selected MSR designs and apply all tools developed at PSI for MSR simulations in last decade. The study should confirm MSR exceptional combination of safety and fuel cycle sustainability.

April 1, 2025

In March 2024 The EU project ENDURANCE was financed by Euratom. The project starting date is set to 1. Octobre 2024. PSI is leading work package 5 dedicated to MSR sustainability and involved also in work package 4 dedicated to MSR transient simulation. The PSI budget will allows to one PhD position and partially other students and postdocs.

November 25, 2023

In November 2023 the final meeting of EU project SAMOSFER took place in Avignon France. PSI was leading work package 3 dedicated to the source term mobility of Molten Salt Reactor (MSR). Several labs were involved to estimate the distribution of nuclides during nominal operation. The radiotoxicity and decay heat release were evaluated at different MSFR system locations and simplified severe accident was simulated. The project was successful in achieving its goals.

September 30, 2023

In September 2023 the project entitled "Definition of fuel cycle performance criteria and assessment of Swiss nuclear waste transmutation options" was financed by SNSF. The aim of the project is to develop methodology and criteria how to evaluate nuclear reactor performance in natural resources utilization and radioactive waste minimization (transmutation). It should provide sounded instrument for reactor intercomparison and focus on the Swiss spent fuel inventory.

November 1, 2021

New issue 02/2021 of the magazine Involved of the association for Switzerland's mechanical and electrical engineering industries SWISSMEM was released. The magazine Involved appears twice a year and address the exciting world of Swiss industry. The latest issue includes part dedicated to “harness of the elementary particles power”. In three distinguished parts, three experts address possibility to use particles for medical purpose, for exact clocks, and for energy production are addressed.

September 24, 2021

Preprint of the Technical Reports Series TRS-489 on the Status of Molten Salt Reactor Technology was released by IAEA. The final publication is expected next year. The responsible officers were Gerardo Martinez-Guridi and Frederic Reitsma. Especially thanks to the editorial and accelerating involvement of the first named the TRS was released in relatively very short time. The document include taxonomy of Molten Salt Reactors, for which PSI expert Jiri Krepel was one of the major co-developer.

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