Official says shutdown for repairs began on Saturday and could last up to four days, possibly causing power outages.
Iran’s only nuclear power plant has been brought back online after two weeks off-grid amid conflicting reports over an apparent regular maintenance operation.
Bushehr plant’s manager Mahmoud Jafari said on Monday that the “technical fault” that shut down the plant’s 1,000-megawatt reactor on Iran’s southern coast was fixed.
That allowed the plant to resume power generation and be reconnected, said Jafari, who is also the deputy head of the Atomic Energy Organization of Iran (AEOI).
Jafari said power generation had resumed from Sunday and urged Iranians to “help” the Islamic Republic’s overburdened grid by minimising power consumption as weather forecasts predicted rising temperatures in the coming days.
Cities across the country, including capital Tehran, have been affected by blackouts that have intensified in recent days, at times extending to several hours and hitting without warning multiple times a day.
On June 20, the AEOI had blamed “a technical fault” for the shutdown and said it had given the energy ministry one day’s notice before going offline.
It said two days later that the issue was with the plant’s “power generator”, without explaining further.
But Iran’s foreign ministry at the time described the shutdown as “routine”, saying it was carried out “once or twice each year”.
Bushehr going off-grid had raised concerns of worse blackouts after a string of power cuts in Iran blamed on heat, drought affecting hydro-electrical facilities, and surging electricity demand.
The sporadic nature of the blackouts and their lack of compatibility with announced schedules have angered citizens and disrupted businesses.
The blackouts have also caused internet disruptions in areas across the country as cell towers were shut down after being left without power for extended times.
Iran’s Information and Communications Technology Minister Mohammad Javad Azari-Jahromi on Sunday apologised for the disruptions, saying “everyone must be accountable for this.”
Power cuts are not uncommon during Iran’s hot summers when air-conditioning use spikes. Adding to the problem, the country’s hydropower capacity has been hit by low rainfall.
A government report in May said precipitation was down 34 percent compared with the long-term average and warned of reduced water supplies for the year.
Since late May, the energy ministry has regularly notified citizens of potential blackouts lasting at least two hours a day.
The Bushehr plant was built by Russia and officially handed over in September 2013.
Russian and Iranian firms started work on two additional 1,000-megawatt reactors in 2016, with construction expected to take 10 years.