This project has received funding from the European Union's Horizon 2020 research and innovation programme under agreement No 945275

PASTELS Participation to the IAEA confencre
Aug. 01 2022

The PASTELS project participates to the IAEA International Conference on Topical Issues in Nuclear Installation Safety (TIC). The TIC-2022 conference is hosted in IAEA Headquarters Vienna, Austria from the 18th until the 21st of October 2022.
Thanks to Christophe Herer from IRSN, Adam Kecek and Ladislav Vyskočil, PASTELS project submitted a paper entitled ” NATURAL CIRCULATION HERO-2 EXPERIMENT SIMULATIONS FOR THE EU FUNDED PASTELS PROJECT”.
If you want to learn more about the conference and registration, follow this link:

Apr. 04 2022

The PASTELS PASI test campaign at LUT University, Lappeenranta, Finland started in March 2022 with the first test, which investigated the effect of loop friction on the open loop flow behavior and heat transfer from containment to the loop. The test was successfully conducted, showing an oscillative loop flow behavior as expected. The downcomer massflow rate is presented in the figure below.

The figure shows how the flow behavior depends on the flow resistance, which was executed by means of closing the shutoff valve in the downcomer line. During the experiment, quasi-steady states were run with six different valve positions starting with the valve fully open. The heat removal loop was able to transfer heat efficiently from the containment vessel to the heat sink and to keep the containment vessel pressure within a safe level. This shows that an oscillating flow can be an efficient heat removal mechanism.

Feb. 02 2022

PASTELS project is happy to announce that it will take part in the upcoming NURETH-19 conference. To follow the presentation given by our project partners make sure to register for the conference.

EDFIRSNCEALUT University and ENEA are gonna be presenting the Passive systems: Simulating the thermal-Hydraulics with experimental studies (PASTELS) on the 9th of March 2022 at 9.00 a.m

Check out the full programme of NURETH-19 by clicking on the following link:

Jan. 31 2022

The PASTELS project has just completed its first P1.1 programme phase on the Safety Condenser (SACO). Therefore, it started the parameter studies on heat transfer for different boundary conditions (variation of the filling level of the SACO pool, presence of non-condensable gases, variation of the core power). We are grateful and proud of the different partners who made this first step possible. The next step is evaluating the various numerical tools of the project on these innovative new test results.

Check out our website to learn more about the project :
PAssive Systems: Simulating the Thermal-hydraulics with ExperimentaL Studies - Home ( )

Jan. 26 2022

The PASTELS phase 1-tests conducted at the PKL test facility this week aims at collecting the first operating experience with a passive decay-heat removal system on the secondary side of a Western-type (Framatome) PWR.
The objective of the experimental activities is to collect experimental data on the heat removal capacity of the SACO in the vertical straight-tube configuration under different boundary conditions and operating states. Both PASTELS phase-1 parameter studies focus on heat transport phenomena in the SACO straight tubes and provide a database for improvement and further development of calculation models in so-called thermal-hydraulic system codes.
The overall goal of the EU-funded PASTELS project is to advance the technical readiness level (TRL) of passive safety systems for future Western-type LWR and improve methodologies and tools applied in the design and safety analysis of such systems.

Jan. 11 2022

The PASI Test Specification is out and currently available on the deliverable section of the webstie. 

Click here to get access



PASTELS project at the International Conference on Topical Issues in Nuclear Installation Safety
May. 01 2022

The PASTELS project is participating this year in the International Conference on Topical Issues in Nuclear Installation Safety
The conference is hosted in Vienna, Austria from the 18th until the 21st of October 2022.
Thanks to Christophe Herer from IRSN, PASTELS submitted an abstract accepted by the Conference and soon will submit the paper.
If you want to learn more about the conference and registration, follow this link:

Jul. 21 2021

Check out our Media Center (Downloads) to know more about WP4 dedicated to the study of Passive Containment Cooling Systems (PCCS) and the development an experimental data base on the PASI test facility operated by the LUT University laboratories. The PASI test specification report introduces the main modelling challenges and presents the test matrix, which is the baseline of future activities

Mar. 19 2021

The PASTELS first public deliverables are now available in the PASTELS Media Centre / Downloads. Go check them out!

Feb. 02 2021

Michael Montout (EDF) was invited to present the PASTELS project at the SNETP Forum 2021 on 3rd February 2021 (9:40 AM CET).

The PASTELS presentation was part of the first technical session, moderated by Pavel Kral (UJV) and Luis Herranz (CIEMAT). This session looked at long term operation and construction, focusing on topics such as hydrogen management, implementation of safety requirements in the post-Fukushima period, perspectives and opportunities for LTO in Europe, etc.

Over 630 participants registered and around 500 participants were actively involved over the 3 days event. All public presentations from the Forum can be downloaded from the SNETP website SNETP FORUM 2021 - Nuclear, an industry of the future - SNETP

Sep. 23 2020

On 24th and 25th September 2020, the 11 project partners gathered online to kick-off the PASTELS project. In the presence of the EC policy officer, Dr. Cristina Fernandez-Ramos, the PASTELS consortium discussed the planning of the first year and the immediate actions after the project start.

During the first day, the Project Coordinator, Michael Montout (EDF) and the WP leaders outlined the overall structure and the management principles. The second day was dedicated to the kick-off of the work packages. These fruitful discussions allowed the team to clarify the interactions among the WPs, the detailed planning, and the expected results.