I’m a master student mechanical engineering and nuclear fusion at the technical university Eindhoven (TU/e). During my internship I had the wonderful opportunity to combine my knowledge on both field into a single project. But I’m happier that I could do it beautiful Italy, where we ate a Pizza every Monday at work for lunch.

When studying as a physicist at TU/e you think of the best possible solution. So when I learned about the water cooled lead lithium blanket module. I thought that is genius, how they came up with this concept. What I did not immediately thought about was what happens when things go wrong? At ENEA Brasimone they think exactly about that. What will happen when in an accident the water will be in direct contact with the liquid metal? An interesting research question indeed and very interesting to learn the other aspects of engineering.

To test this they are constructing a simulation tool and in order to validate this tool also simulations will be performed. In their research facility called LIFUS5 a small amount of high pressurized and temperature water is injected in a vessel filled with liquid metal. At the end of the first experiments the pressure sensor showed a different pressure in the reaction vessel as in the water injection line. This was unexpected as the flow should be in equilibrium at this point in time. To figure out what was going on here I made a nodilization of this water injection line in RELAP5/Mod3.3, which is thermonuclear code and mostly used for safety analysis in nuclear powerplants. One pressure sensor was a dynamic pressure sensor, meaning that it only measures the pressure difference. At the start of the experiment the injection line is vacuumed and therefore the pressure sensor is set at zero. With this code however I was able to show that there was a small leakage through the valves. This increased the pressure at the start of the experiment, so it was wrongly reset to zero, hence the difference in pressure at the end of the procedure. 3

What I especially liked about this project was the difference between theory and practice. In theory the cooling tubes will never break. At university the code you are using is wrong when you are not getting to the same answer. In practice also the data from the experiments can be misinterpreted.

- Jos Scholte