A South Korean research reactor was evacuated yesterday after workers detected an unusually high level of radiation.

Shortly after 2:30 PM local time on 20 February, officials declared a a “white radiation emergency” at the 30MW HANARO reactor at the Korea Atomic Energy Research Institute (KAERI) in Daejeon. Several workers were either evacuated or forced to take cover.

According to Reuters, the accident took place as researchers were exposing silicon ingots to neutron radiation from the reactor core. The neutrons transmute some of the silicon into phosphorus, effectively doping it and allowing it to be used in specialized electronics. It appears that contaminates from the reactor rose to the surface of a water pool that provides radiation sheilding and triggered the alarm.

HANARO went critical in 1995, and is currently being used for a variety of neutron-related experiments. A press release on the incident (in Korean) can be read here.

Image: KAERI