Stockholm, Jul 2 (IANS): The restart of a Swedish nuclear reactor which was due to be operational by the end of June following maintenance work has been postponed by three more weeks, media reported.

The Ringhals 3 reactor will instead restart on July 19, Johan Pettersson, a spokesperson for the electricity company Vattenfall, which owns and operates the Ringhals nuclear power plant, told Swedish Television (SVT) on Saturday.

"At the end of the maintenance period, another task was added," Pettersson said.

Another reactor, the Ringhals 4, was originally scheduled to be reconnected to the energy system last November, following repairs of a pressure vessel that was damaged in August. The restart date was pushed back several times until the reactor was eventually restarted in April this year.

But Pettersson added that the scale of the current problem is not comparable with the previous one of the Ringhals 4, Xinhua news agency reported.

Following the decommissioning of four reactors between 2017 and 2020, six reactors remain at three sites and produce around 30 per cent of the electricity in Sweden, according to the Swedish Energy Agency.

Since last summer, some of the remaining reactors have at times been offline for extended periods due to maintenance and technical problems, which has at times led to electricity price peaks.