Ellen Phiddian
Cosmos science journalist
The Kakhovka dam in southern Ukraine has been blown up, sending a flood of water downstream.
The dam supplies water to the Zaporizhzhia nuclear power plant, which has been held by Russian forces since early March last year.
While the plant needs water to keep its cooling system operating, the dam’s explosion is unlikely to cause an immediate risk to the plant.
The plant is upstream of the dam, so isn’t threatened by the flood of water.
“The plant has got its own cooling pond topped up by the reservoir,” says Tony Irwin, technical director of SMR Nuclear Technology and chair of Engineers Australia’s Sydney division nuclear engineering panel.
This cooling pond is sufficient to prevent any risk of meltdown for a while – particularly since the reactors are all shut down, meaning they need less water to keep cool.
“Short-term, I can’t see a big problem, long-term, they’ll need a way to keep that cooling pond topped up,” says Irwin.
The dam burst, meanwhile, is demonstrating a more immediate risk to 15 towns downstream which have been ordered to be evacuated.
It also housed a now-inoperative hydroelectric plant, which places further strains on Ukraine’s electricity supply.
According to the International Atomic Energy Agency, Zaporizhzhia nuclear power plant – the first ever nuclear power plant to be captured by an invading army – has been “extremely vulnerable” for three months now because of its lack of an external back-up power supply.
This means that the plant is relying on one functioning power line to stay cool, and on-site diesel backup generators.
The loss of the Kakhovka dam places a further, but not urgent, strain on the plant.