Ongoing problems at Zaporizhzhia Nuclear Power Plant

The Zaporizhzhia Nuclear Power Plant (ZNPP) in Ukraine has become one of the most contentious and high-risk sites in the Russia–Ukraine conflict. Over the past few years, a series of combat-related incidents, power outages, administrative struggles and international interventions have combined to transform it from a commercial energy facility into a focal point of geopolitical, safety, and symbolic stakes. Here we provide an overview of the major events, challenges, and implications surrounding ZNPP, including an assessment of most recent events.

Background and Strategic Importance

The Zaporizhzhia plant is the largest nuclear power station in Europe. It is located near the city of Enerhodar in southeastern Ukraine, on the Dnipro River, and has been a critical part of Ukraine’s energy infrastructure. 

Following the Russian invasion of Ukraine in February 2022, Russian forces seized control of the plant during the Battle of Enerhodar on 4 March 2022. This marked the first time a fully operational nuclear power plant was occupied during an armed conflict.  Since then, the plant’s status and safety have been at the center of repeated crises and international concern. 

Under occupation the plant has continued to be staffed (largely by its Ukrainian personnel under duress), but its operations, oversight, safety, and grid connections have been severely disrupted. 

Timeline of Key Incidents and Crises

Early Shelling and Damage (2022)

• In August 2022, after the occupation, shelling near the plant damaged critical infrastructure such as transformers, radiation sensors and cabling.

• On 5 August 2022, the 750 kV electrical switchboard was shelled, triggering shutdowns of some reactors and protective systems. 

  
  

• The International Atomic Energy Agency (IAEA) raised deep concerns about the integrity of the facility, the ability to maintain safe operations, and the necessity of independent inspections. 

  
  

• At times, the plant operated in a “grid island mode,” relying on its own reactors to power safety functions, foot in danger due to the unstable external electrical supply. 

  
  

• In September 2022, the final reactor was disconnected and the plant was placed in cold shutdown. 

Ongoing Siege and Blackouts

• Over subsequent months and years, the plant experienced repeated loss of off-site power lines due to combat damage or shelling of energy infrastructure. 

  
  

• Each time the plant loses external power, it depends on its emergency diesel generators to maintain critical cooling systems and safety functions. 

  
  

• As of September 2025, a new blackout event—reportedly the tenth since occupation—disconnected the plant from Ukraine’s power grid, forcing it onto diesel generators. 

  
  

• The blackout raised acute safety fears because operating on diesel backup is never intended for extended durations, and there is a danger if generators fail or fuel supply is inadequate. 

  
  

• The IAEA has described the situation as “deeply concerning.” 

Cooling Water Crisis

• The plant depends heavily on water from the Kakhovka Reservoir (via the Kakhovka hydroelectric dam) for reactor cooling and spent fuel pool operations. 

  
  

• In June 2023, the Kakhovka Dam was breached, draining the reservoir and jeopardising the plant’s primary water source. 

  
  

• As mitigation, new underground wells were installed to supply cooling water to spent fuel ponds, and contingency measures were taken. 

  
  

• Nevertheless the loss of the reservoir reduces redundancy and heightens vulnerability in crisis scenarios. 

Attempts to Restart, Administrative Control, and Legal Status

• Russia has expressed intentions to integrate the plant into its own grid and to have Rosatom (its state nuclear company) manage or own the facility. 

  
  

• In 2025 some statements by the plant’s director suggested planning for regulatory alignment under Russian oversight by 2028, although Ukraine strongly rejects such proposals. 

  
  

• The IAEA however, has said that under current conditions, a safe restart cannot take place—citing unstable power supply, insufficient cooling water and operational hazards.

• Ukraine maintains that a restart by Russia is unsafe, risky, and a violation of both national sovereignty and nuclear safety norms. 

  
  

• In March 2025, Russia formally declared the plant to be a Russian facility and rejected joint operation proposals. 

Recent Escalations and International Concerns

• In mid-September 2025 shelling was reported near the Zaporizhzhia plant, raising alarms about proximity combat and collateral damage. 

  
  

• As of the time of writing in late September 2025, the plant has been without external power for over 48–72 hours—its longest sustained outage yet—with safety maintained via diesel backup. 

  
  

• Some analysts warn that Russia may be engineering a crisis—forcing outages to justify restarting the plant under her control. 

Risks, Challenges and Implications

Nuclear Safety Risks

• Loss of external power is one of the gravest risks at a nuclear facility: it reduces redundancy for cooling systems, backup systems must suffice, and any failure of backup systems or fuel shortage for generators threatens overheating or core damage.

  
  

• The presence of ongoing hostilities, artillery and shelling near the plant increases the risk that structural or safety systems will be damaged.

  
  

• The reduced water supply from the Kakhovka breach means cooling margins are thinner.

  
  

• The forced staffing environment, chain-of-command confusion and divided control raise the risk of human error, miscommunication, sabotage or mismanagement.

Legal, Political and Symbolic Stakes

• The plant has become a symbol of the war’s nuclear dimension: its control confers not only energy leverage but also a potential instrument of coercion or blackmail.

  
  

• International norms and nonproliferation regimes are challenged: the occupation of a nuclear facility during combat is unprecedented and strains the existing regulatory frameworks.

  
  

• The IAEA has repeatedly called for a demilitarised safety and security zone, free from attacks and military presence; enforcement has been weak. 

  
  

• The plant’s status is disputed: Russia insists it is now Russian, while Ukraine and much of the international community demand return to Ukrainian control. 

  
  

• There are fears that a severe accident—however unlikely—would have transboundary consequences far beyond Ukraine (including principally in Russia, given the prevailing winds).

Energy and Economic Impacts

• Before the war, ZNPP contributed significantly to Ukraine’s electricity grid. Its removal from reliable service worsened Ukraine’s energy stability, especially under wartime stress.

  
  

• The plant’s marginalisation forces more reliance on other (often fossil) energy sources, leading to economic strain and increased vulnerability to infrastructure attacks.

  
  

• The plant is also a bargaining chip: control over it, or claims to own its output, nourishes geopolitical maneuvering.

Outlook and Possible Scenarios

Given the current trajectory, several possible paths emerge:

1. Continued Status Quo Under Russian Control

   
   

   The plant remains non-operational (in cold shutdown), powered by emergency systems, and remains a flashpoint. Occasional shelling, outages, and standoffs continue.

   
   

2. Restart Under Russian Management (But High Risk)

   
   

   Russia may attempt to restart certain reactor units, connecting the plant to her grid, especially if she can resolve cooling and power stability issues. But the IAEA and Ukrainian authorities warn this is risky under wartime conditions. 

   
   

3. Return to Ukrainian or Neutral Control

   
   

   Diplomatically or militarily, Ukraine (with international backing) could seek to regain full control. This would require demilitarisation, assurance of safety, and stable infrastructure—an uphill task in the midst of war.

   
   

4. Catastrophic Failure (Low Probability but High Impact)

   
   

   In a worst-case scenario (multiple cascading failures, loss of backup power, cooling breakdown, or attack on critical systems), a radiological accident could result. While many safeguards exist, the wartime environment makes “normal” safe operation far more fragile.

In all these scenarios, a key variable remains: external oversight, inspection access, and enforcement of nuclear safety norms. The IAEA continues to monitor and issue warnings and resolutions, but its capacity to enforce is limited without consent and cooperation from the parties. 

A geopolitical chess piece

The saga of the Zaporizhzhia Nuclear Power Plant during the Russia–Ukraine conflict underscores how nuclear infrastructure can become a geopolitical chess piece and a locus for risk when and where war intersects with high-stakes energy and safety systems. The plant’s occupation, repeated blackouts, damaged supply lines, cooling crises and administrative ambiguity all combine to create a precarious equilibrium. Each side—Ukraine, Russia, and international observers—views the plant not just as an energy asset but as a symbol of control, sovereignty and the resilience (or vulnerability) of modern nuclear norms.

As of late 2025, the plant remains in limbo: externally powerless, under de facto Russian control, but not producing electricity in a standard sense. Whether it is restarted, returned or further enmeshed in conflict, the world is watching, aware that the consequences of a failure here extend far beyond local boundaries.

Timeline: 2022–2025

4 March 2022 — Seizure of ZNPP. Russian forces take control of Europe’s largest nuclear station amid fighting near Enerhodar, an unprecedented occupation of a functioning nuclear plant. The IAEA establishes a continuous presence later to monitor safety. 

August–October 2022 — Shelling and the first extended blackouts. Repeated strikes cut external power lines; the plant several times shifts to emergency diesel generators to maintain cooling and essential safety functions. By mid-October, lines are again severed, underlining the fragility of off-site power. 

June 2023 — Kakhovka dam breach and cooling-water shock. The destruction of the dam that fed the plant’s reservoir forces improvised water sourcing (wells, alternative circuits) and narrows safety margins for long-term cooling of reactors and spent fuel. 

2024 — IAEA reiterates: safety degraded, restart not credible. Missions document continued post-dam constraints and the need to insulate the site from hostilities; demilitarisation and stable power/water are repeatedly urged. 

4 July 2025 — Grid cut for hours, then restored. All external lines drop for roughly three and a half hours before restoration, with the IAEA warning that nuclear safety across Ukraine remains “extremely precarious”. 

Mid-September 2025 — Shelling reported near ZNPP. The watchdog again calls for restraint as monitors observe renewed nearby explosions. 

23–27 September 2025 — Tenth blackout since occupation, the longest so far. At 16:56 on 23 September, the last 750-kV line is disconnected and diesel generators take over. IAEA experts on site confirm the switch; industry briefings cite ~20 days of diesel stocks if refuelling is possible. By 27 September, external power is still down, making this the lengthiest sustained outage of the war. 

What the blackout string tells us

1. Loss of off-site power is the headline risk at ZNPP. Modern reactors are designed to fail-safe, but prolonged reliance on diesel is outside design intent; any interruption in fuel, air intake, lubrication or emergency switchgear can create cascading hazards. The present multi-day outage underscores how war conditions erode redundancy. 

   
   

2. Cooling margins are thinner post-Kakhovka. Alternative water sources exist, but the destruction of the primary reservoir removed a key layer of resilience; sustained station blackout scenarios are therefore more sensitive. 

   
   

3. Operational clarity is compromised. Divided control, staff pressure and regulatory ambiguity elevate the risk of error or delayed response, which in nuclear operations can be as consequential as hardware failure. (This is the IAEA’s recurring theme across its field notes.) 

   
   

4. A wartime restart remains ill-advised. The IAEA Director-General has said there is “no way” to restart safely under present conditions; Ukraine’s operator concurs. Suggestions of reconnecting the plant to non-Ukrainian grids amidst blackouts heighten controversy rather than reduce risk. 

Practical guard-rails (what would actually reduce risk)

• Hard deconfliction around the site. A verifiable, ring-fenced no-fire / no-drone zone with access corridors for line crews and diesel resupply. Even partial implementation that protects the switchyards would markedly cut blackout frequency. 

• Power-line redundancy and rapid repair capacity. Pre-positioned spares for high-voltage equipment, mobile substations and escorted repair teams reduce the duration of each outage, which matters as much as frequency. 

• Diesel and air-handling resilience. Assured fuel stocks, periodic load-testing and protected intake/exhaust paths for generators; in parallel, contingency cross-ties for house loads from nearby thermal units if physically feasible. 

• Cooling-water safeguarding. Continuous monitoring of well yields and temperature margins; additional pumps and filtration redundancy for spent-fuel pools; contingency plans for temporary heat-sink augmentation. 

• Human-factor protection. Rest cycles, unimpeded staffing shifts, and on-site liaison with IAEA observers to keep procedures and authority lines coherent under stress. 

Bottom line

ZNPP today sits in a precarious but stable-for-now equilibrium: reactors are in shutdown, diesel keeps essential systems alive, and each severed power line resets the clock on a well-understood but unforgiving engineering problem. The present September 2025 outage, the tenth of the occupation and the longest to date, is not just another tally mark; it is a stress-test of how long emergency measures can hold in wartime conditions—and a reminder that the only robust remedy is to remove combat from the plant’s perimeter and restore reliable, redundant grid and cooling pathways.