---
title: "Paks NPP back in action: Hungary restarts reactors halted by record Danube low-water levels"
description: "Hungary resumed operation of the third unit of the Paks NPP on August 22 after a record Danube low-water event. The plant, which supplies 40% of the country's electricity, was running at 10% capacity at the peak of the crisis. To save the reactors, authorities built an underwater dam from barges."
date: 2026-08-23T02:56:01.000Z
lang: en
url: https://xab.info/en/posts/paks-npp-back-in-action-after-danube-crisis
tags: [hungary, paks-npp, danube, nuclear-energy, energy-crisis, romania, cernavoda, climate-impact]
publisher: "XAB.info"
---

# Paks NPP back in action: Hungary restarts reactors halted by record Danube low-water levels

![Paks Nuclear Power Plant in Hungary: reactor building with MVM Paksi Atomerőmű sign and cooling towers as reactors resume after Danube low water](https://xab.info/media/2026/08/23/aes-paksh-vnov-v-rabote-posle-krisisa-na-dune/aes-paksh-vnov-v-rabote-posle-krisisa-na-dune-1.webp)

## 🎯 Key Points

- Paks NPP resumed operation of its third unit on August 22 after a shutdown caused by the record-low Danube level
- At the peak of the crisis the plant was running at 10% capacity (one of four reactors), with output of 481 MW
- Hungarian authorities built an underwater dam from stone-loaded barges to raise the water level near the plant
- A similar crisis hit the Cernavodă NPP in Romania, where Nuclearelectrica began purchasing electricity from Ukraine

Hungary is resuming operation of the first of three reactors at the Paks nuclear power plant, which had been forced to shut down due to the record-low water level in the Danube. According to Madyar, a representative of the energy sector, the third unit was started up on Saturday evening, August 22, 2026. The decision became possible thanks to the gradual rise in the river level and a set of emergency measures taken by authorities in the midst of the summer energy crisis.

### Crisis on the Danube: how heat stopped a quarter of Hungary's power generation

Summer heat waves sweeping across continental Europe led to a critical drop in water levels in the region's major waterways, including the Danube. For the Paks NPP — Hungary's only nuclear plant, providing about 40% of national electricity production — this became a direct threat: nuclear reactor cooling systems require constant access to a sufficient volume of water. At the most severe period, the plant was operating at only a tenth of its 2000-megawatt design capacity — of the four reactors, only one remained in operation. At the time of resumption, the third unit's output was 481 megawatts, confirming that even the single operating reactor was running with a slight underload relative to the nominal 500 MW.

### Emergency measures: an underwater dam made of barges

To prevent a complete shutdown of the plant, Hungarian authorities resorted to an unconventional engineering solution — an underwater dam made of barges loaded with stones was built in the river at the plant's bank. The structure is designed to raise the water level directly in the cooling water intake zone. In parallel, the government increased electricity imports from neighboring countries and appealed to households and businesses to voluntarily reduce consumption. According to operators, as early as the beginning of August the plant was far from full capacity, and before that, due to the record drop in water level, it had been shut down completely — the country's only nuclear plant had been taken out of service.

### Resumption of operations: what is known about the start-up of the third unit

According to information provided by Madyar, energy workers will resume operation of the third unit on Saturday evening, August 22. This is the first of the three shut-down reactors to be returned to service. It is expected that, once the Danube level stabilizes, the remaining two units will be started up, allowing the plant to return to full 2000 MW capacity. Nevertheless, experts emphasize that even after full restoration, Paks will remain vulnerable to a recurrence of the hydrological crisis, as climatic conditions in Central Europe are becoming increasingly extreme.

### Regional context: Romania and the supply chain

A similar problem arose acutely in neighboring Romania. The last operating reactor of the Cernavodă NPP was on the verge of shutdown on August 13 due to a lack of cooling water. To cover the resulting electricity deficit, the Romanian company Nuclearelectrica began purchasing electricity from Ukraine with the support of Moldovan supplier Energocom. Thus, the crisis on the Danube affected several countries in the region and exposed the systemic dependence of the nuclear energy sector in Central and Eastern Europe on hydrological conditions.

### Hungary's energy security in question

The events of summer 2026 became a serious test for Budapest's energy strategy, which relies heavily on nuclear generation. Dependence on 40% of electricity produced by a single plant makes the economy extremely sensitive to external factors — from climate anomalies to geopolitical restrictions on imports. The resumption of Paks operations eases the current crisis, but the question of adapting infrastructure to new climatic realities remains open and will likely require additional investment in modernizing cooling and water supply systems.

## 🔍 Fact-Check Verification

- [Paks NPP in Hungary to start up again thanks to a simple solution](https://www.rbc.ua/ukr/news/aes-paksh-ugorshchini-znovu-zapratsyue-zavdyaki-1787453518.html) - Источник подтверждает факт возобновления работы остановленных реакторов АЭС «Пакш» после обмеления Дуная, а также упоминает экстренные меры по поднятию уровня воды. Данные согласуются с базовым текстом новости.

## ❓ FAQ

### Q: How many reactors at Paks NPP were shut down and how many have resumed operation?
**A:** Of the plant's four reactors, three were shut down due to the low Danube level. On August 22, 2026, the first of them — the third unit — resumed operation. The remaining two units will be returned to service as the river level continues to stabilize.

### Q: What emergency measures did Hungarian authorities take to save the NPP?
**A:** An underwater dam made of barges loaded with stones was built in the river at the plant's bank to raise the water level in the cooling water intake zone. In addition, Hungary increased electricity imports and called on the public and businesses to voluntarily reduce consumption.

### Q: What is Paks NPP's share in Hungary's power supply?
**A:** The plant provides about 40% of all electricity produced in Hungary. Its design capacity is 2000 megawatts (four reactors of 500 MW each).

### Q: Did the Danube crisis affect other countries in the region?
**A:** Yes. In Romania, the last operating reactor of the Cernavodă NPP was on the verge of shutdown on August 13. The company Nuclearelectrica began purchasing electricity from Ukraine with the support of Moldovan supplier Energocom to cover the deficit.