Fire at Korea Zinc Onsan Smelter ESS Center, Ulsan, South Korea

In August 2023 a fire broke out inside a two-storey indoor battery energy storage facility used for peak shaving at the Korea Zinc Onsan Smelter ESS Center (Plant 1) in Onsan-eup, Ulju-gun, Ulsan, South Korea, operated and owned by Korea Zinc. The fire started in the morning and fire services declared a level one emergency response, deploying all available equipment and personnel from the local fire department. Firefighters used smoke extraction vehicles to clear smoke from the building, then drilled openings into the structure so that remote controlled, unmanned water cannons could apply water directly to the fire. More than seven hours after ignition, firefighting was still in progress. Reports noted that once a fire starts in this type of battery storage system it tends to continue burning until the stored energy is consumed, making full suppression difficult. No information on injuries, cause or final extinguishment time was available at the time of reporting.

No contributing factors were stated in the source. Reporting at the time noted only the general difficulty of suppressing fires in enclosed lithium-ion battery installations.

1. Plan on the basis that fires in indoor lithium-ion battery installations can be very difficult to extinguish and may burn for many hours until the stored energy is consumed, so incident command, water supply and crew relief arrangements should be sized for an extended duration.
2. Pre-agree tactics with the local fire service for enclosed installations, including remote operated or unmanned water application and controlled venting or drilling of the enclosure to reach the seat of the fire without committing crews inside.
3. Design indoor and enclosed battery storage buildings with features that support this response, such as defined access and breaching points, smoke extraction or venting provision, and clear marking of module and compartment layout.
4. Provide responders with pre-incident plans showing electrical isolation points, stored energy at each level of the building and the routes for applying water from outside the structure.

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