what the largest nuclear power plant in the country looks like and works

The first thing I thought when entering the nuclear energy complex where the Angra 1 and 2 plants are located, in the state of Rio de Janeiro, was: “Is this really safe?” I confess. Even though we know that there has never been a serious case in Brazil, it is inevitable not to remember the case of explosions at the nuclear power plants in Fukushima, in Japan and Chernobyl, in Ukraine. To this day, the exact extent of the damage caused is not known.

But, considering that Angra 1 and 2 have been operating since 1985 and 2001, respectively, and hundreds of people have worked there for decades, it seemed reasonable to visit. Especially because there is greater curiosity in getting to know a plant from the inside and knowing how it works. Especially in Brazil, where there are only these two in operation – and the third is a white elephant.

There are 436 nuclear plants in operation in the world and 57 under construction, of which 21 are being built in China. Around here, the third unit under construction is Angra 3 – but that has been almost 40 years ago.

The visit was made inside the Angra 2 plant, the largest in the complex. With a power of 1,350 megawatts (MW), it can meet the consumption of a city with more than two million inhabitants, such as Belo Horizonte. Next door is Angra 1, whose power is 640 MW, energy capable of supplying a city like Porto Alegre.

Both are operated by Eletronuclear, a subsidiary of ENBPar, a state-owned company created to manage Itaipu and Eletronuclear after the privatization of Eletrobras. The complex that houses them is in Angra dos Reis and is called Central Nuclear Almirante Álvaro Alberto, in honor of the soldier and scientist who was one of the main organizers of the Brazilian nuclear program.

The production is sent to the National Interconnected System (SIN), which connects electricity networks across almost the entire country.

The complex also houses Angra 3, which began to be built in the 1980s, but to date only 65% ​​of the work has been completed.

Problems with bidding and budget restrictions are some of the reasons for delays. The last one was in 2015, as a result of investigations into Operation Lava Jato. The new delivery forecast is 2029. In addition to the R$7.8 billion already invested, Eletronuclear estimates that around R$20 billion will be needed for the plant to be ready.

Cell phones out, radiation and turnstiles

The visit inside Angra 2 is technical, open only to groups of companies and schools, and must be scheduled. The general public can learn more about the history in the planetarium where the stages and data of the complex are presented.

In the first part of the technical visit, some theoretical information is given about how nuclear energy is produced, its capacity and power, general specifications of the three plants and studies to use the green hydrogen that is already produced there and from smaller modular reactors.

This is a path that has been taken in other countries, but is incipient in Brazil. More economically viable, “mini nuclear plants” can also help solve one of the sector’s main problems: the population’s fear of an explosion accident. The impact would be smaller, and therefore it is believed that acceptance of projects of this type could be greater.

Nuclear energy is considered a relevant source in the energy transition, as it does not require fossil sources, such as coal and oil, and due to its large production capacity with a relatively small amount of matter. Today, this source is responsible for 1% of the energy matrix in the country.

The energy contained in a 7-gram pellet of uranium (the size of a piece of gum) is equivalent to that of a ton of coal or 22 trucks of diesel oil. The main negative point is toxic and radioactive waste, which requires careful treatment.

To actually enter the Angra 2 plant, visitors have to leave their cell phones outside. There is a lot of confidential data that cannot be exposed there.

Employees can bring smartphones, but the internet does not always work. In the reactor room, there’s no point trying: use is prohibited because the device could become contaminated with radiation. Access to the site requires special protective clothing.

To prevent hacker attacks on the system, the building does not have an internet connection. Communication is carried out via radio, telephone and intranet, which leads the emergency meeting room to reinforce contact through five telephone models – including a fax, a device that I haven’t seen in a long time.

(For those who were born in the era of fast internet, fax is a kind of WhatsApp printout, a printed communication between two landlines. Something like an iPhone 15 Pro Max from the 1990s.)

The room also contains all procedures documented on paper and recent information on the latest problems. In other words, in the event of a problem in the circuit, it is possible to resort to the “analog” model.

The operations room is made up of 10 thousand buttons and 7.5 thousand alarms. The operators, all men, take turns. They undergo tests periodically and must retake tests every two years.

These are very specific roles with great responsibility, with a salary of up to R$50,000. The harassment from other companies is great, such is their knowledge, says one of the executives. Next to the plants there are villages where some of the employees live. These are some of the benefits.

Between signs, turnstiles and warnings, the impression is that the operational part is similar to driving a vehicle: you accelerate, brake, turn signal, drive the car, but everything on “automatic”. Attention is focused on avoiding accidents. The driver is more concerned about the car in front, the motorcycle that cuts on the right side, the cyclist who appears suddenly than, actually, driving, because if he does not control his surroundings to minimize possible accidents, the result can be fatal. .

In the controlled area with even more restricted access are the turbines (the green structures in the photo at the beginning of the text). They are moved by the steam generated after nuclear fission. There is also the generator, which converts it into electricity and sends it to the SIN.

We passed through at least four closed turnstiles from top to bottom, doors, corridors, walkways. In all cases, it was necessary to present the badge received at the entrance, which contained each person’s identification, with data previously passed on. You must wear a helmet and safety glasses.

Gustavo Souza Pinheiro dos Santos, simulator instructor at Angra 2, says that Brazilian plants “are not at risk of exploding”, as happened in Fukushima, Japan. The systems are different, he explains: while at the Japanese plant the primary and secondary schools were mixed, in Brazil this does not happen.

“In their system, you have more income. In Brazil, we chose to lose yield to have safer reactors. It is the most used model in the world. France, Germany and Sweden use it”, says Santos.

Incidents raise doubts about transparency

There are many supporters of nuclear energy in Brazil, as an energy source that does not emit greenhouse gases. The main barrier is the fear of accidents.

The Almirante Álvaro Alberto Nuclear Power Plant has four levels of severity of occurrences. Employees guarantee that none have passed the first level. On the other hand, they also say that from the second level onwards they do not officially communicate to the press so as not to alarm the population.

In other words, the public is not aware of problems ranging from simple to serious, which can fuel mistrust.

In this sense, an episode that occurred in September 2022 at the Angra 1 plant drew attention. At the time, there was a leak of radioactive water in Itaorna Bay, which was not immediately reported to the inspection bodies. Ibama and the National Nuclear Energy Commission (CNEN) were notified just 21 days after the episode.

Ibama fined Eletronuclear R$2.1 million for irregular disposal of a radioactive substance and failure to comply with the operating license, and the Federal Public Ministry took action against the company.

Eletronuclear only spoke publicly in March 2023, when the case became public. The company said that there was “an unscheduled release at the plant of around 90 liters of water containing substances with a low radioactive content” and that, as the values ​​were “well below the limits of legislation that characterize the occurrence of an accident”, it dealt with of the episode as an “internal operational incident”.

“The value verified was much lower than that received by an individual undergoing a chest x-ray and around 1,000 times lower than the annual exposure from natural radiation, present in our daily lives”, pointed out the then president of Eletronuclear, Eduardo Grand Court, in a statement at the time.

How nuclear energy is produced in Angra 2

The energy in Brazilian nuclear plants is generated by nuclear fission – the breaking of an atom, in this case, uranium. This breakdown releases energy, which is converted into heat – and this happens billions of times, simultaneously, inside the reactor.

This heat heats the demineralized water (completely clean) that is inside the reactor, in a closed system.

Gustavo Bidetti Mardegan, an Eletronuclear employee who led the visit, simplifies: “It’s like a shower heater. The resistance heats up and transfers this heat to the water that passes through it.”

He continues: “This heated water leaves the reactor through pipes and will exchange heat with a second water, which is inside the steam generator. When heated, this second water turns into steam, which, in turn, is directed to the turbines, making them rotate. At the tip of the turbine there is an electrical generator, which transforms the movement into electrical energy.”