The creation of Nucleoeléctrica Argentina S.A. (NA-SA) cannot be understood without considering the gradual weakening of Argentina’s nuclear sector following the return to democracy in 1983. Throughout those years, the country’s sole governing body of nuclear activity, the National Atomic Energy Commission (Comisión Nacional de Energía Atómica or CNEA), was shaped by three structural factors that would condition its subsequent evolution: the exodus of highly qualified personnel, the demilitarization of the institution, and sustained budget cuts that forced a downsizing of the Nuclear Plan inherited from the dictatorship.

This process culminated in the state reform of the 1990s, during which the federal government pursued a broad agenda of deregulation and privatization in the electricity generation sector.According to the government’s own rationale, the main objective was to reduce reliance on public financing in investments deemed high-risk¹, such as nucleoelectric generation, by bringing in private capital. This approach carried particular weight in the nuclear field, where the development and expansion had depended entirely on federal funding.

Against this backdrop, Decree No. 1540/1994laid down the regulatory framework for the reform of the Argentine nuclear sector. It removed the operation of power plants from the Commission’s remit through the creation of NA-SA, and established the Nuclear Regulatory National Agency (Ente Nacional Regulador Nuclear or ENREN), later renamed the Nuclear Regulatory Authority (Autoridad Regulatoria Nuclear or ARN). For the first time in the country, commercial operation and regulatory oversight of the nuclear sector were placed in separate hands.

The reform’s rationale was part of a broader state-restructuring program. It consisted of ring-fencing nucleoelectric generation within a joint-stock company, transferring to it the Commission’s assets, personnel and operating contracts, and setting the legal conditions for its subsequent privatization. Under this scheme, NA-SA was incorporated as a joint-stock company with the federal government as its sole shareholder², and took over the operation of Atucha I and Embalse, along with the construction, commissioning and future operation of Atucha II.

The recitals of the decree stated that “the expansion of nucleoelectric generation supply depends on the contribution of public funds, and it is both advisable and necessary to concentrate federal efforts on social areas and to avoid participation in high-risk investments”, and further that “it is advisable for the Atucha II Nuclear Power Plant to be completed in a timely manner and at reasonable cost.”

On this logic, responsibility for directing and executing the construction of Atucha II, and of any future nuclear power plants, was to be transferred progressively to the private sector.

The recitals of the decree stated that “the expansion of nucleoelectric generation supply depends on the contribution of public funds, and it is both advisable and necessary to concentrate federal efforts on social areas and to avoid participation in high-risk investments”, and further that “it is advisable for the Atucha II Nuclear Power Plant to be completed in a timely manner and at reasonable cost.”

On this logic, responsibility for directing and executing the construction of Atucha II, and of any future nuclear power plants, was to be transferred progressively to the private sector.

ENACE and the Atucha II project

Until then, much of what the decree described had been carried out by the Commission through the Empresa Nuclear Argentina de Centrales Eléctricas – Sociedad del Estado(or ENACE S.E.)

ENACE was a mixed-ownership company established in 1979, with 75% of its capital held by the Commission and 25% by the German firm Siemens-KWU. It was conceived as the executive arm of the 1979 Nuclear Plan, enacted during the last military dictatorship, and took on responsibility for the architecture, design, engineering and management of the nuclear power plants contemplated under that plan³.

Its core mandate included providing integrated project management for the works, involving domestic industry in the nuclear program, administering technology transfer contracts, and prequalifying supplier firms, all with the aim of building up local capabilities in component manufacturing of and nuclear services.

The creation of ENACE also marked a significant organizational shift within the Argentine nuclear sector. The company was intended to ensure that management of the works planned under the Nuclear Plan would be centralized in a dedicated, specialized structure until completion. At the same time, the shareholder arrangement provided for Siemens-KWU’s stake to taper off as the program advanced, disappearing altogether at the start of construction of the plan’s last power plant, in line with the objective of consolidating greater national autonomy.

By the early 1980s, ENACE had acquired manufacturing licenses for large components of the Atucha II plant and employed roughly 700 people, most of them qualified professionals and technicians. It had also taken an active part in technology transfer to domestic suppliers, as well as in the construction of steam generators and pressurizers, working with the German-Austrian consortium KWU–MAN GHH–Voest Alpine.

Atucha II: launch and paralysis

Construction of the Atucha II nuclear power plant formally began in 1981, with commissioning scheduled for mid-1987. From 1982 onward, however, the Nuclear Plan began to suffer recurring delays, driven chiefly by financing shortfalls. Cumulative setbacks forced successive reschedulings of the plant’s completion to 1989, 1991 and 1993, none of which were met.

By the end of the decade, the sector was in the grip of an operational crisis.

In 1987, both the Atucha I and Embalse nuclear power plants had to be taken offline. Although the outages were initially described as maintenance work, when Atucha I was brought back online in December of that year a significant incident occurred: tubes ruptured after the closure plug of a fuel-free channel came loose, causing a spill of roughly 60 tonnes of heavy water. After a subsequent restart and further operational difficulties, the plant went offline again in April 1988⁴. Embalse was also taken out of service that same month  due to technical problems, resuming operation in mid-May.

These episodes deepened the operational instability that marked the Argentine nuclear fleet throughout this period.

Meanwhile, the Atucha II works were sliding into an increasingly untenable financial position. Budgetary constraints, treasury shortfalls  and, by 1988, the refusal of international banks to extend further financing brought ENACE to the brink of complete stoppage. By the early 1990s the Commission was in critical condition: years of accumulated delays on the works, an inability to meet its financial commitments to Siemens-KWU, and cost overruns far beyond the project’s original budget.

Construction of Atucha II was ultimately halted in 1995. In mid-1996 ENACE S.E. was liquidated, and the remaining assets and personnel were transferred to NA-SA as part of the institutional restructuring set in motion in 1994.

Full transfer to NA-SA

The institutional reform was completed when ENACE S.E.’s shareholding was transferred to NA-SA,along with the staff of the Commission’s Nuclear Power Plants Area Management. NA-SA thus absorbed not only the assets and contracts tied to nuclear power  generation, but also the personnel, the technological capabilities and the execution and operating responsibilities that until then had been spread across different entities in the nuclear sector.

As noted above, the original design of this restructuring was meant to pave the way for eventual privatization of nuclear power generation. Over time, however, the very process of concentrating functions inside NA-SA produced a company of such operational and financial complexity that any straightforward transfer to the private sector became difficult.

Unable to privatize NA-SA on the terms originally envisaged, the government turned to a technical-financial workaround intended to make privatization viable through a leaner structure. In 1998 it accordingly created Generadora Nuclear Argentina S.A.(GENUAR S.A.) as an alternative vehicle for attracting private capital.

GENUAR was conceived as a concessionaire limited to the commercial operation of the nuclear fleet, separated from design, engineering, project execution and technological development, which remained concentrated in NA-SA. The aim was to offer the private sector a more manageable and predictable asset, avoiding the direct transfer of all the liabilities, obligations and contingencies accumulated by the state-owned company, which would instead be handled through dedicated trust vehicles.

Under the official scheme circulated at the time, private capital would gain control of the new company through a 45-year concession over the nuclear assets. In the proposed arrangement, 89% of the share capital would be held by the awarded private operator, 10% would go to workers through an Employee Shareholding Program, and the federal government would retain a golden share allowing it to intervene in strategic decisions. The concessionaire would also be required to finance the  completion of Atucha II.

At that time, Atucha I and Embalse were generating roughly 7,000 GWh/year, or about 12% of national electricity generation. With Atucha II eventually online, total nucleoelectric supply could have risen to around 12,000 GWh/year.

Despite the new legal and institutional design, privatization of the nuclear fleet never materialized: the scheme proved economically unworkable and technologically too complex. On the latter point, Atucha II, meant to be the centerpiece asset for attracting investors, was in practice a high-risk liability. The works had been at a standstill for years, with significant cost overruns, obsolete critical components and non-standardized technology⁵; completion would require redesign, requalification and substantial investment, with no clear visibility on payback horizons or expected returns.

Compounding this was a contradictory regulatory landscape. Section 37 of Law No. 24,065 barred the company from generating profits, a condition incompatible with any privatization process. Operating nuclear power plants also carried strict regulatory requirements, the need for specialized insurance, the constitution of decommissioning funds and compliance with a dedicated nuclear civil-liability regime, burdens no private operator was willing to assume without substantial federal backing.

The deteriorating macroeconomic climate of the late 1990s finally closed off any remaining path toward privatization or concession of the Argentine nuclear fleet.

Transition and relaunch of the Nuclear Plan (2006)

After the failed privatization attempt and the stoppage at Atucha II, the Argentine nuclear sector entered a period of stagnation that lasted until the mid-2000s. This began to reverse in 2006, when the federal government relaunched the Argentine Nuclear Plan and recast NA-SA no longer as a vehicle to be privatized but as the central actor responsible for completing Atucha II, operating the nuclear fleet and delivering strategic projects. A new phase of expansion and recovery of nucleoelectric capabilities was thereby opened.

The failed privatization attempt nevertheless left behind a state-owned company that concentrated technical capabilities, highly specialized human resources and strategic operating responsibilities, yet lacked a business model originally designed to sustain that expanded role over the long term.

Even so, over the following decade, and on the back of public financing, NA-SA succeeded in completing the construction of Atucha II and reaching criticality in 2014. It also carried out the Embalse Life Extension Project between 2014 and 2018, extending the plant’s operating life by thirty years. Together with the Commission, it delivered the ASECQ-I project (dry storage for spent fuel elements from Atucha I). In 2023, NA-SA repaired a significant fault at Atucha II, reaffirming its standing as an operator with in-house technical capabilities to manage events affecting its nuclear fleet.

Seen from this angle, NA-SA’s institutional trajectory looks less like the deliberate rollout of a comprehensive model set out in its original design, and more like a pragmatic adjustment to shifting political and economic conditions . The company took on functions and built capabilities as the opportunities and constraints of each stage allowed, without the backing of a consistent nuclear policy that clearly defined its strategic mission and its place within the sector.

The present

In September 2025, Decree 695/2025 authorized the procedure for the partial privatization of NA-SA through a share sale, once again making the company the  object of an opening to private capital, although on a different operational footing from before. Today, the company has a headcount of roughly 2,800–3,100 employees for a net installed capacity of about 1,640 MWₑ (Atucha I, Atucha II and Embalse⁶). This process is unfolding in parallel with the Atucha I Life Extension Project⁷, fully financed with public funds. The estimated investment stands at around USD 700 million and is intended to secure at least twenty additional years of operation. Notably, this project represents the largest single budget allocation to public works under the current administration of President Javier Milei.

The current situation does, however, differ in important respects from the 1990s. First, the legal framework has been amended by the addition of Section 37 bis to Law No. 24,065/2025, which exempts NA-SA from the exclusive cost-recovery regime and allows it to earn profits. Second, the federal government has already absorbed the highest-risk investments in the nuclear cycle: Atucha II is complete and operating, Embalse has undergone its life extension, and the Atucha I life extension will be funded from the Treasury.

In practice, nonetheless, the new context once again lays bare the absence of a clearly defined governance model for the Argentine nuclear sector. As in the 1990s, the state continues to play a central role in funding capital-intensive investments, while simultaneously reintroducing privatization proposals for the company. This overlap of logics shows that what is at stake is not so much the legal form of the company as the lack of a strategic definition of how the nucleoelectric sector should be organized, governed and institutionally sustained.

The history of Nucleoeléctrica Argentina S.A. raises a series of questions that illustrate how the absence of a consistent, long-term nuclear policy has made it difficult to redefine the company’s role with any clarity. After the failed privatization of the 1990s, the trajectory of the state-owned company exposes an unresolved dilemma: whether its main function should be limited to operating the nuclear fleet, or whether it should also consolidate itself as the designer, integrator and executor of major nuclear projects.

***
Translated into English by Tamara Dayoub.

Bibliography

• https://www.argentina.gob.ar/normativa/nacional/decreto-1540-1994-13030/texto
• https://www.scielo.org.ar/scielo.php?pid=S2422-65802017000100003&script=sci_arttext&utm
• https://www.lanacion.com.ar/economia/se-privatizan-las-centrales-nucleares-nid105356/
• https://web.archive.org/web/20140714194143/http://edant.clarin.com/diario/96/12/01/O-03001d.htm
• https://servicios.infoleg.gob.ar/infolegInternet/anexos/60000-64999/62252/norma.htm
• https://econojournal.com.ar/2024/11/extension-vida-atucha-i-proyecto-us-700-millones-eficiente-segura-central-nuclear/

Notes

¹The decree’s reference to “risky investments” must be read in the context of the economic policy of the period. From a technical-economic perspective, nucleoelectric generation is more accurately characterized as a capital-intensive activity, with high sunk costs, long payback horizons and a strong dependence on stable financing conditions, rather than as a risky investment in the strict sense.
²99% of the shareholding belonged to the federal government and 1% to the then-company Agua y Energía Eléctrica.
³Decree No. 302/1979, Section 1(a), approved a nuclear plan consisting of four 600 MWe nuclear power plants, with commissioning scheduled for 1987, 1991, 1994/5 and 1997, together with the corresponding fuel-cycle and heavy-water production facilities.
 ⁴Resolving the incident at Atucha I involved considerable technical complexity and required the design and construction of dedicated equipment, work carried out by a technical team drawn from the Commission and the companies INVAP, CONUAR and Techint.
⁵The expression does not refer to the absence of comparable technological precedents, given that the Siemens/KWU PHWR design had other applications, but rather to the fact that Atucha II was not part of a standardized industrial and commercial platform. Its prolonged paralysis, obsolete components, the need for redesign and requalification, and the lack of serialization conditions comparable to other reactor technologies compounded the technical complexity and economic uncertainty of its completion.
⁶As a comparative reference, international literature typically puts the direct operation and maintenance headcount of a nuclear power plant at around 600 employees per year for every 1,000 MWₑ during the operating phase, though this figure can vary depending on reactor type, the number of units per site, the degree of outsourcing, and whether the company counts only on-site personnel or also corporate, engineering and support functions.
⁷Atucha I: 360 MWe net installed capacity, approximately 2,531 GWh net per year.