SEOUL-- South Korea's nuclear watchdog said Thursday that it has launched a probe into the cause of the automatic shutdown of the research reactor in Daejeon, some 160 kilometers south of Seoul.

The Nuclear Safety and Security Commission (NSSC) sent an investigation team to determine the cause of the automatic stoppage of the High-flux Advanced Neutron Application Reactor (HANARO) at 5:43 p.m., the watchdog said.

The NSSC believes the hydrogen pressure anomaly in the cold neutron source facility was the cause of the research reactor's stoppage.

The cold neutron source facility is used to analyze the structure of cells and others by using neutrons generated from nuclear reactors.

The nuclear reactor of HANAO has been stabilized as its reactor coolant pump has been working normally, the NSSC said.

The alarm device detecting a radiation leak has not been triggered, it added.

The NSSC said it will set up measures to prevent the research reactor from closing down after investigating the cause.

Source: Yonhap News Agency