Nucleoeléctrica Argentina has begun testing equipment for the ASECG II dry storage facility (Almacenamiento en Seco de Combustibles Gastados de Atucha II), considered essential for the long-term operation of the Atucha II reactor. The Argentine operator says the facility will be able to hold up to 50,000 used fuel elements on the plant site. It includes a passive ventilation system that keeps the elements within a safe temperature range without requiring electricity or human intervention, according to Nucleoeléctrica. The work is part of a broader push to strengthen the reliability of nuclear fuel, echoed by the International Atomic Energy Agency’s project to optimize fuel testing.
Cooling ponds nearing capacity
Used fuel is typically stored underwater for at least five years, and often much longer, after being removed from the reactor, allowing it to cool and its radiation levels to decline. At Atucha II, the cooling ponds are expected to reach full capacity by the end of next year, according to Nucleoeléctrica, which says the new facility is essential to keep the plant running. A similar dry storage facility was already commissioned in 2022 for Atucha 1, designed for fuel assemblies from the pressurised heavy water reactor.
IMPSA’s gantry crane undergoing testing
Among the equipment being tested is a gantry crane tasked with safely moving containers within the facility. Designed by Argentine company IMPSA based on a technical specification from Nucleoeléctrica, it was delivered at the end of 2025. Installation and commissioning were scheduled to take place over a four-month period. This expansion of storage capacity comes as several countries seek to consolidate their existing nuclear fleets, illustrated by Russia’s plan to add 30 GW of nuclear capacity and expand its exports.
A project launched in 1979, completed three decades later
Atucha II is a 693 MWe pressurised heavy water reactor (PHWR) ordered in 1979 to a Siemens design, an enlarged version of the first Atucha unit. Construction, which began in 1981, was carried out through a joint venture between Argentina’s National Atomic Energy Commission (CNEA) and Germany’s Siemens-Kraftwerk Union. Lack of funding slowed the work, which was suspended in 1994 when the project was 81% complete.
Operating licence renewed until 2036
Nucleoeléctrica Argentina, established in 1994 to take over the country’s nuclear plants from CNEA, oversaw the completion of the project, which was presented to the government in 2003 and later folded into a national strategic plan announced in August 2006. The unit was effectively completed in September 2011, reaching first criticality in June 2014 and full power in February 2015. Last May, the Autoridad Regulatoria Nuclear issued a renewed 10-year operating licence, valid until May 2036.
