R1 (nuclear reactor)
R1 was the first nuclear reactor of Sweden. 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. The reactor was active from July 13, 1954 to June 6, 1970. The reactor was dismantled, and there is nothing left of it today; the reactor hall however still exists. History. 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. – but also to produce medical isotopes. The capacity of the reactor was originally 300 kW but was later increased to 1 MW. "R1" was housed in a large hall reminiscent of a cathedral giving it the nickname the “Cathedral of Science and Technology”. Rolf Sievert served as the head of the radiation department at KTH Royal Institute of Technology and gave the approval to run the reactor. "R1" was soon overtaken by Studsvik for nuclear research and on June 6, 1970 "R1" was dismantled. Today. 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. It is open to the public during limited times for tours. In 2016, the reactor hall was used to film the music video for Alan Walker's song "Faded (Restrung)". The video was released on 11 February 2016.