The Ministry of Trade, Industry and Energy (MOTIE) announced it will pursue additional safety measures based on the results of the ESS fire investigation. It plans to clarify the legal permit classification standards for ESS, unify the previously department-varying entrance-door standards for high-pressure gas storage facilities, and extend the ESS lease period from 10 to 15 years (per MOTIE press release).
Mechanism-Perspective Impact Analysis
The core of ESS fire safety measures ultimately comes down to a thermal-runaway propagation-prevention structure. The spacing between modules within a battery rack, the material and thickness of the barrier, and the venting gas exhaust path are equipment design variables. As the permit standards and entrance-door standards move toward unification, barrier design matched to fire-compartment standards and pressure-relief paths must be reflected in drawings from the equipment layout design stage to prevent permit delays. The extension of the lease period to 15 years also affects mechanical design. It means the fatigue life and corrosion margin of the rack structure must be re-reviewed on the assumption of long-term operation.
Similar regulatory tightening is underway overseas. The 2026 edition of NFPA 855 (the U.S. ESS installation standard) centers on thermal runaway fire propagation (TRP) prevention, requiring design-stage propagation mitigation based on test data showing a large-format 587Ah cell can release roughly 1,174 liters of flammable gas (about half hydrogen) (source: E2News). Accepted mitigation measures include module spacing/compartmentalization, thermal barrier materials, water-mist or clean-agent suppression systems, and improved cabinet-internal structures (same source).
On certification, cell- or module-level testing alone is no longer sufficient; rack- or system-level UL9540A large-scale fire test data has become effectively mandatory (source: E2News). Permitting procedures have also been tightened to require submitting a Hazard Mitigation Analysis (HMA) and an Emergency Response Plan (ERP) to fire authorities before installation, along with mandatory annual review and training (same source). Korea’s domestic rules and U.S. NFPA 855 are separate regulatory systems, but both share the same design goal of preventing thermal-runaway propagation, so barrier and venting designs should be checked against both.
Spec Comparison Table
| Item | Revision Direction (MOTIE Announcement) | Mechanical Design Response Point |
|---|---|---|
| ESS Permit Standard | Legal classification clarified | Equipment layout drawings must align with permit drawings |
| High-Pressure Gas Storage Facility Entrance Door | Unified standards across departments | Door interlock and opening-width specs need review |
| ESS Lease Period | 10 years → 15 years extension | Long-term operation requires re-review of rack structure fatigue life |
| Thermal runaway propagation prevention (NFPA 855, US) | ~1,174L flammable gas per 587Ah-class cell (test data) | Reflect module spacing, thermal barriers, suppression systems in design |
| Certification testing (NFPA 855, US) | Rack/system-level UL9540A large-scale fire test effectively mandatory | Cell/module-level testing alone is no longer sufficient for certification |
Design Reflection Checklist
- Verify fire-compartment/barrier standards are consistent between domestic permit drawings and equipment layout
- For overseas-bound projects, pre-review UL9540A rack/system-level test requirements under NFPA 855
- Recalculate rack structural fatigue life and corrosion margin for the extended 15-year lease term (on-site verification required)
One-Line Summary
Unifying ESS safety regulation is a signal to reflect barrier and venting-path design from the earliest drawing stage.