The unexpected outage is currently estimated to last just over a month, from today, Monday, until March 28, according to a statement from the Nord Pool electricity exchange.
"The reason is that the sealing of a number of valves needs to be checked," says owner OKG's communications manager Théresé Andersen.
"Safety is our top priority. So at the slightest doubt that everything is not as it should be, we stop the plant to investigate the matter further," she continues.
After that, the annual inspection, the overhaul of the reactor, will begin, according to Andersen. The reactor is therefore not expected to restart until May 22.
Time of high prices
The shutdown of one of Sweden's six nuclear power reactors comes at a time of already high electricity prices, even though the worst price peaks have subsided as the cold loosens its grip on the Nordic region.
Ahead of Tuesday, the electricity price on Nord Pool is rising significantly, although as usual there are several factors that influence it. The average price during Tuesday is around 1.25 kronor per kWh throughout the country, up from 90 öre on Monday.
"Unfortunately, it feels a bit like the higher prices might persist," says Patrik Södersten, electricity price analyst at Fortum.
And in the financial markets, where future electricity prices are traded, the immediate reaction was about 5 öre higher for March.
Reserves are shrinking
The severe cold with high consumption, coupled with less precipitation than normal, has already depleted hydropower reserves.
"So this will mean a longer period where we risk drawing heavily on our hydropower," says Patrik Södersten.
Especially in electricity area 4 (SE4), prices may rise as a result of the reactor shutdown, predicts Johan Sigvardsson, electricity analyst at Bixia.
"Forsmark 3 will undergo regular inspection on March 8, and now with O3 out of operation, transmission capacity to SE4 will be low while we still have winter after all," he writes in an email response to TT.
