# Krško Nuclear Plant output cut amid low Sava water

> Live situation record from CLSTR: https://clstr.news/situations/krko-nuclear-plant-heat-wave-output-cut
> Updated: 2026-08-05T08:39:08.000Z. Sources: 24. Developments: 2.

The Krško nuclear power plant (NEK) began a planned, controlled reduction to about 80 % of its capacity (≈530 MW) on the night of 6 August 2026 because of exceptionally low water levels and high temperatures in the Sava River, which risk breaching its environmental permit limits of a 28 °C average daily temperature and a 3 °C rise. The plant, jointly owned by Slovenia’s GEN energija and Croatia’s Hrvatska elektroprivreda (HEP), supplies roughly 20 % of Slovenia’s electricity and 16 % of Croatia’s demand. After completing a refurbishment in November 2025, the reactor operated continuously for 280 days—the longest stretch since a similar reduction in 2003 that lasted over 90 days. Operators indicated that further reductions could follow if river conditions deteriorated, and full power would resume once temperature and flow return to permissible levels. HEP affirmed it can cover any shortfall through its own generation and market purchases.

## Claims

- Krško nuclear plant will reduce reactor power to 80 % on the night of Thursday 6 August 2026. (corroborated by 15 sources)
- Krško nuclear plant supplies about 20 % of Slovenia’s electricity and 16 % of Croatia’s electricity consumption. (corroborated by 14 sources)
- If hydro‑meteorological conditions worsen, further power reductions may be applied; full power will resume when conditions allow. (corroborated by 14 sources)
- The 80 % output corresponds to about 530 MW, down from the plant’s full capacity of 659 MW. (corroborated by 13 sources)
- The reduction is caused by low water level and high temperature of the Sava River, which risk exceeding environmental limits of 28 °C average temperature and a 3 °C daily rise. (corroborated by 13 sources)
- The plant has been operating continuously since the end of its refurbishment in November 2025, achieving 280 days of uninterrupted operation. (corroborated by 12 sources)
- The last similar power reduction occurred in 2003 and lasted more than 90 days. (corroborated by 12 sources)
- Hrvatska elektroprivreda (HEP) can meet any electricity shortfall by using its own generation and purchasing on the wholesale market. (corroborated by 3 sources)

## Timeline

### 2026-08-05: Krško nuclear plant cuts output to 80% amid low Sava water levels

Krško nuclear plant will reduce output to 80 % (~530 MW) on 6 Aug 2026 due to low Sava water levels and high temperatures; the temporary measure meets environmental limits and may be extended if conditions stay

16 sources. https://clstr.news/cluster/slovenian-krko-nuclear-plant-reduces-reactor-power-amid-heat-wave

### 2026-08-02: Krško Nuclear Plant May Reduce Output as Sava River Temperatures Rise

Heat‑wave‑driven Sava River temperatures threaten Krško Nuclear Plant’s cooling, prompting warnings of possible power cuts or shutdown within days.

9 sources. https://clstr.news/cluster/krko-nuclear-plant-may-reduce-output-or-shut-down-over-sava-river-limits

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Cite as: Krško Nuclear Plant output cut amid low Sava water. CLSTR, https://clstr.news/situations/krko-nuclear-plant-heat-wave-output-cut