R1 was the first nuclear reactor of Sweden. It was a research reactor located at the Royal Institute of Technology (KTH) campus at Valhallavägen in central Stockholm, in the rock beneath the current-day Q-Houses. The reactor was active from July 13 1954 to June 6 1970. The reactor was dismantled, and there is today nothing left of it, but the reactor hall still exists. The effect of the reactor was originally 300 kW but was later increased to 1 MW.
