Argentinian nuclear utility Nucleoeléctrica Argentina SA (NA-SA) has secured the necessary funds to carry out the life extension project of unit 1 of the Atucha NPP. Nucleoeléctrica President Dr Alberto Lamagna confirmed that the plant’s maintenance outage would begin on 29 September, the day marking the end of its first operating cycle after 50 years of power generation.

Atucha I, Latin America’s first NPP, in the town of Lima in Buenos Aires province, is a 362 MWe pressurised heavy water reactor (PHWR) that began commercial operation in 1974 with a design life in its operating licence of 32 equivalent years of full power. The licence was first extended in 2018 to 2024.

“The project will allow Atucha I to operate for 20 more years, ensuring its contribution to the national energy matrix and promoting the development of technical capacities that position Argentina in the global market for nuclear services, “said Lamagna. He also highlighted the commitment from the national government for “strengthening and expanding Argentina’s nuclear potential, in the context of global revitalisation of this type of energy, that offers development opportunities through the incorporation of private capital”.

Atucha I, like any industrial facility, has a design lifespan that marks the period during which its components and equipment can operate safely and efficiently. After this cycle, a life extension stop must be made, which will last 30 months and will allow the maintenance, inspections and improvements necessary for the plant to operate safely for a new cycle.

In June, Argentina’s Nuclear Regulatory Authority (ARN – La Autoridad Regulatoria Nuclear) provided an update on plans for the Long-Term Operation (LTO) of Atucha 1. The LTO project comprises Stage A, which began in 2018, followed by a Prolonged Period of Reconditioning (PPR) now underway, and Stage B.

When (NA-SA) notified ARN of its intention to extend the life of Atucha 1 beyond its original design life, in line regulatory requirements, NA-SA carried out exhaustive evaluations on different aspects of plant and its past operation. These were independently reviewed by ARN, which concluded that safe operation beyond its original design life was possible. ARN determined the need for various activities and the LTO project was divided into two stages (A & B).

ARN Authorised Stage A by amending Atucha 1’s operating licence in April 2018. This allowed NA-SA to continue operation of the unit during this stage while it undertook studies and establish programmes that would ensure that the design bases of the installation were maintained. Stage A has now been completed and the PPR has begun with an expected duration of at least two and a half years. This will allow ARN to verify in detail the implementation of the updates and improvements required from NA-SA to raise the design bases of the facility to the required security level.

During the PPR outage Atucha I will carry out these improvements, which will result in a plant with safety characteristics superior to the original design. The selection of these improvements was defined following extensive evaluations required and reviewed by ARN. Stage B will include LTO measures following completion of relevant updates and improvements undertaken during the PPR outage.

In January 2023 NA-SA launched a financial trust to support sustainable investment in two nuclear power projects- life extension of Atucha 1 and construction of a second used fuel dry storage facility at the site. NA-SA said the trust was set up for a total of $600m through six tenders. This will cover both projects, which are estimated to cost $463m for the unit 1 licence renewal and $137m for the storage facility. NA-SA said $30m was raised in the first round of the tender. A second tranche of $93m was raised in April 2023.

NA-SA produces some 8% of Argentina’s electricity through the operation of three nuclear plants, all PHWRs, with a total installed power of 1,763 MWe. These include Atucha I, Atucha II, which began operation in 2014, and the Embalse NPP launched in 1983.

Atucha 1, which began operation in 1968, was designed and built by KWU, a joint venture of Germany’s Siemens and AEG. Siemens was sold to the reactor business of France’s Areva now owned by EDF and trading as Framatome.

Atucha 2, ordered in 1979, was a Siemens design, a larger version of unit 1. Construction started in 1981 by a joint venture of the Comision Nacional de Energia Atomica (CNEA) and Siemens-KWU. However, lack of funds caused delays and work was suspended in 1994 when the plant was 81% complete. In 1994, NA-SA was set up to take responsibility for NPPs from CNEA, including the construction of Atucha 2. The unit was completed in 2011 and first criticality was in 2014. The plant was licensed in 2016.

The Embalse NPP is a 683MWe Candu-6 reactor which began operation in 1983. A 30-year life extension was completed in 2019 after a three-year outage. The work involved Canada’s SNC Lavalin and L3 MAPPS, Italys’ Ansaldo and the Argentia’s CONUAR, IMPSA, Techint, SACDE.

Researched and written by Judith Perera