R1 (nuclear reactor)

It was a research reactor located at the KTH Royal Institute of Technology campus at Valhallavägen in central Stockholm, in the rock beneath the current-day Q buildings.

As World War II came to a close, the Swedish government in 1950 formed a group of physicists and engineers to study and learn more about the basics – reactor physics, radiation, materials, etc.

Rolf Sievert served as the head of the radiation department at KTH Royal Institute of Technology and gave the approval to run the reactor.

After being dismantled, the hall that R1 sat was deemed safe and was used for events like art exhibitions, concerts and music videos due to its interesting aesthetic and acoustics.

[3] In 2016, the reactor hall was used to film the music video for Alan Walker's song Faded (Restrung).