Two nuclear reactors in Sweden were shut down in the morning due to a brief blackout caused by a short circuit at a Stockholm power station. Ten hours after the incident, there was no safe forecast as to when they would reopen.

The two reactors at the Forsmark nuclear power plant, 150 kilometers northeast of the Swedish capital, automatically shut down after the power cut.

Staffan Norga, a professor at the Royal Institute of Technology in Stockholm, spoke of “a very unusual event” underlining to the newspaper Dagens Nyheter that the energy deficit is significant, since each reactor has a capacity of 1 GW.

On the same wavelength were also the statements of Professor Olof Samuelsson from the University of Lund, an expert in electrical energy systems. “Until recently we considered the largest possible loss to be in the order of 1,450 MW,” he told the same newspaper, thereby underlining the impact of today’s loss.

The two experts shared the view that the incident reveals vulnerabilities in the Swedish electricity system.

After the decommissioning of four reactors (2017-2020), six reactors remained in operation at three sites and, according to the Nordic country’s regulator, almost 30% of the electricity produced in Sweden today comes from nuclear power plants.

Since the summer, some of the remaining nuclear reactors have been temporarily shut down for maintenance work and technical problems, contributing to higher energy prices.