Sweden could be facing a serious loss of power generating capacity as several of its nuclear stations could be forced to close indefinitely.

The country’s SKI nuclear regulation agency is to decide how the industry should proceed following a worrying electrical failure at the country’s Forsmark plant, causing the closure of two reactors there.

This centered on a short-circuit of equipment used to cool the reactors, and the incident was classified as a two out of a possible seven on the scale of atomic safety breaches, according to the International Atomic Energy Agency.

The Forsmark incident caused the closure of a further two reactors at Oskarshamn operated by E.ON’s local arm.

We can’t say how long the reactors will remain shut down, the SKI’s spokesman Anders Bredfell told the BBC. The Oskarshamn reactors were shut down because they couldn’t prove that the same thing [as happened at Forsmark] couldn’t happen there.

There has been media speculation that the Forsmark incident came close to being much more serious. The lack of power to the plant made a meltdown in the reactor core a realistic possibility, green campaigners claim.

However the authorities say the incident proved that safety measures do work as intended.