Ferosplavna-1
The 330 kV backup feeder line to ZNPP; damaged 1.8 km from the switchyard; sole functional line in April 2026.
Last refreshed: 13 May 2026 · Appears in 1 active topic
With both ZNPP power lines compromised, what stands between the plant and diesel-only cooling?
Timeline for Ferosplavna-1
Rosatom Turns on IAEA as ZNPP Hits Day 60
Russia-Ukraine War 2026Served as sole remaining backup line keeping ZNPP on external power
Russia-Ukraine War 2026: ZNPP Day 50: nuclear alert sensors destroyed- What is the Ferosplavna-1 line at Zaporizhzhia?
- Ferosplavna-1 is ZNPP's 330 kV backup feeder, the fallback external power supply when the primary 750 kV Dniprovska line fails. Additional damage to it was found 1.8 km from the switchyard during April 2026 repairs.Source: IAEA
- How many times has Zaporizhzhia Nuclear Plant lost all external power?
- ZNPP has lost all external power sixteen times since the full-scale Russian invasion began in 2022. The April 2026 week saw the fourteenth and fifteenth occurrences before a partial restoration.Source: IAEA
- Why does repairing ZNPP's power lines keep failing?
- Each repair requires an IAEA-brokered local Ceasefire around the plant. Ceasefires have broken down repeatedly, and fighting resumes before long-term repairs can be completed. By mid-May 2026, the IAEA was attempting to negotiate its sixth such arrangement.Source: IAEA Director General Grossi
Background
Ferosplavna-1 is the 330 kV backup feeder line that provides an alternative external power supply to Zaporizhzhia Nuclear Power Plant (ZNPP) when the primary 750 kV Dniprovska line fails. In April 2026, when the Dniprovska was repaired via an IAEA Ceasefire and then lost again, repair crews reached the Dniprovska switchyard and simultaneously discovered additional damage on the Ferosplavna-1 line approximately 1.8 km from the switchyard. At that point, one external line was running — the only thread of grid connectivity keeping the plant off diesel generators.
The Ferosplavna-1 line operates at a lower voltage than the primary Dniprovska feeder, making it less capable of sustaining full plant loads. It has been the subject of IAEA-brokered Ceasefire repairs — an April 2026 Ceasefire was specifically negotiated to restore it. The pattern across both power lines shows a structural vulnerability: Ceasefire repairs restore a line, then fighting resumes and damages it again, cycling the plant through repeated blackouts. ZNPP has lost all external power sixteen times since the full-scale invasion began.
The IAEA treats Ferosplavna-1 as the last-resort grid connection before ZNPP falls onto diesel-only operation. The combination of a disconnected primary line (Dniprovska, out 50 days as of 13 May) and a damaged backup places the plant in what nuclear safety protocols classify as a degraded external power state — one category below full loss of coolant, but with the same directional trajectory.
