The ignition point of the fire that broke out at the Daejeon headquarters of the National Information Resources Service (NIRS), where the country's key information systems are concentrated, has been identified as the uninterruptible power supply (UPS) battery. The battery was found to have no issues during a routine inspection in Jun., fueling controversy over the cause of the accident.
According to the Ministry of the Interior and Safety and the National Fire Agency, the fire occurred at around 8:20 p.m. on 26th in a computer room on the fifth floor of the NIRS Daejeon headquarters. While servers and UPS lithium-ion batteries were being separated and moved to the basement to protect the computer systems, one battery exploded and the flames spread.
The battery in question was supplied by LG Energy Solution between 2012 and 2013, and it is known that the UPS manufacturer used the battery to build the equipment and then delivered it to the NIRS.
According to the NIRS, a routine inspection of the UPS lithium-ion batteries in the computer room was conducted in Jun., and no anomalies were found at the time. The NIRS operates about 600 major administrative systems, including Government 24, Korea Post, and the Ministry of the Interior and Safety website.
However, in the battery industry, there is a view that "this explosion is more likely due to issues in the power shutdown process than to a defect in the battery itself." UPS equipment uses direct current, not alternating current used in typical households. Given this characteristic, if wires or cables are disconnected before the power is completely shut off, the voltage can spike momentarily and destroy insulation. In this process, sparks or an explosion may occur.
An industry expert warned, "When moving or disconnecting a UPS battery, you must work with the power completely off," adding, "If it is disconnected with even a small amount of residual current flowing, it can lead to a major fire."
The National Fire Agency plans to conduct a joint investigation with the National Forensic Service and the police to determine the cause of the fire as soon as the scene is cleared.