The Autoridad Regulatoria Nuclear (ARN) says the new licence would take Atucha 2 up to the end of its first 10 years of commercial operation, a decade which has seen a number of licence extensions.
In December 2015 ARN granted a conditional operating licence for Atucha 2 until May 2016, and issued its initial five year licence on 26 May 2016 following the completion of a programme of testing, training and other actions. The first, two year, extension was granted in May 2021 but the unit was shut down from October 2022 for repairs after the discovery that one of the four internal supports of the reactor had detached and moved from its design location.
That led to ARN issuing a second short-term extension to 26 May 2024, so that Nucleoeléctrica Argentina, could "implement corrective improvement actions". After verifying that Nucleoeléctrica had implemented these actions "in compliance with the established safety requirements" the regulator authorised the unit's entry back into service in August 2023, following a 10 month shutdown.
Nucleoeléctrica says that to achieve the renewal, the regulator had "verified that the company carried out all the modifications and improvements to guarantee the safe and reliable operation of the plant", which is located in the city of Lima, Zárate, 115km from Buenos Aires.
The second unit is a 693 MWe pressurised heavy water reactor and was ordered in 1979. It was a Siemens design, a larger version of the first unit at Atucha, and construction started in 1981 by a joint venture of Argentina's National Atomic Energy Commission and Germany's Siemens-Kraftwerk Union. However, work proceeded slowly due to lack of funds and was suspended in 1994 with the plant 81% complete.
In 1994, Nucleoeléctrica Argentina was set up to take over the nuclear power plants from CNEA and oversee construction of Atucha 2. In 2003, plans for completing Atucha 2 were presented to the government. The government announced a strategic plan in August 2006 for the country's nuclear power sector, including completion of Atucha 2. The unit was effectively completed in September 2011. First criticality was achieved early in June 2014, and grid connection was later that month, with full power in February 2015.