Brazil, a party to the Non Proliferation Treaty, is reportedly planning to develop indigenously a nuclear-propulsion system: the nation's first submarine is expected to be operational by 2017; its first nuclear submarine by 2023.
If Brazil develops a nuclear submarine, it would be South America's first, and enable Brazil to project itself as a "developed country with sophisticated industry capable of absorbing, mastering and using advanced technologies."
The nuclear submarine program is based on Pressurised Water Reactors, which enable a submarine to deliver a large amount of power from very low amount of energy, Brazil could could use either Low Enriched Uranium, nuclear fuel enriched up to 20% which is "easier and less expensive to acquire," or Highly Enriched Uranium, processed between 50-90%.
Evidently prompted by the lessons of Falklands War of 1982, as well as by a desire to protect Brazil's large off-shore oil reserves in the Amazon region, Brazil took its first step toward establishing a sea-based deterrent in 2009, when its leadership decided to develop five submarines -- some of them nuclear-powered.
During the Falklands War, a British nuclear-powered submarine sank the Argentine cruiser General Belgrano, propelling both Argentina and Brazil to recognize the importance of a strong navy. As Brazil has always advocated Argentina's claims over the Falkland Islands, an increased projection of power from Brazil could be of concern to Britain.
At present, Brazil's navy, built largely in cooperation with France is seen as a "key part of the country's new national armaments and defence strategy."  Submarines are "a key part of Brazil's effort to build a modern navy that can defend its oil and trade interests in the South Atlantic, a region long dominated by British and U.S. navies," where United States "patrolled, shadowed, trailed and tracked Soviet strategic submarines as part of their forward deployment strategy."
The naval expert Ambassador Paul D. Taylor has pointed out three maritime goals in Brazil's national defence concept: "Sea denial, control of maritime areas, and power projection." Brazil's navy is responsible for the protection of some 7400 km of coastline, of which, submarines would form an integral component. The submarines could be used not only to attack the lines of communication of adversaries, but also for power projection "through the disembarkation of special forces, for intelligence collection, and for laying mines".
The Scorpène class conventional submarine designed to maximise stealth and have low acoustic, magnetic, electro-magnetic, and infra-red signatures is reportedly to be used for "anti-submarine warfare, special operations and intelligence collection." Flexible cables to be used are for reduction of noise; and special low-noise emission components for rotating machinery.  Conventional submarines, however, may not be sufficient to protect Brazil's oil wealth; hence, the need for nuclear powered submarines.
The Scorpène-class submarine Carrera SS-24, in service with the Chilean navy. (Photo source: WikiMedia Commons)
Mauricio Santoro, a political scientist, writes that the nuclear submarine technology would enable the Brazilian navy to "create a "production prototype," which could be used subsequently in other naval vessels, such as aircraft carriers.
Brazil is part of the BRICS group of emerging economies (Brazil, Russia, India and China, South Africa). All members except South Africa have ventured into nuclear powered submarine programs. Brazil may also be concerned about Chile's submarine capabilities. Although Chile does not possess any nuclear attack submarines, its Scorpène class submarine can be fitted with anti-ship and anti-submarine torpedoes as well as anti-surface missiles. An advantage with Scorpène class submarines is that they can be fitted with air-independent propulsion, which means they can stay submerged for a longer duration than those with conventional propulsion. Argentina is also eyeing nuclear powered submarines, but equipped, at least for now, with conventional weapons.
In Venezuela, Russia is building naval capabilities, including nuclear-powered guided-missile cruisers and anti-submarine ships.
Nuclear submarines would, therefore, in the words of Brazilian President Rousseff, "allow [Brazil] to affirm itself on the world stage, and, above all, develop in an independent sovereign way
Towards Nuclear Weapons Proliferation
Brazil's nuclear submarine would apparently mean a "revival of nuclear development by the Brazilian military that was halted in 1990 with the end of the country's nuclear bomb program." In 2000, however, Brazil's government began exploring a civil nuclear program. Even though Brazil is officially a party to the Non Proliferation Treaty, former President Lula da Silva criticized the NPT as discriminatory toward non-nuclear-weapons states. Brazil's unwillingness to join the Additional Protocol of the Nuclear Non Proliferation Treaty further signals efforts toward nuclearization.
Venezuela's close collaboration with Russia and Iran may result in the proliferation of nuclear material or weapons from these countries to Venezuela. There were reports in 2011 that Venezuela, in collaboration with Iran, was building missiles deployed within range of the United States.
Brazil would be reasonable to conclude that even basic nuclear capability could deter hostile South American states or other rival attempts on its vast oil resources.
Brazil's constitution bans the development of nuclear weapons; also, as a member of Agência Brasileiro-Argentina de Contabilidade e Côntrole de Materiais Nucleares (ABACC), the country would be subject to the monitoring of all nuclear stockpiles. Still, the agency's ability to prevent Brazil from becoming nuclear state is questionable. Moreover, the NPT has a loophole for the non-nuclear-weapons states: in a "critical non-proliferation concern for international community,"  members can legitimately stockpile large amounts of enriched, weapons-grade uranium, resulting, as with Brazil, in their drifting away from the treaty.
Of note, therefore, is Brazil's support for the development of nuclear weapons as a crucial tool of deterrence: to portray itself as an important player in international politics and possibly an eventual bid for permanent membership in the United Nations Security Council.
Brazil carries out its nuclear submarine construction in areas it considers "restricted military areas" that bar investigation from the International Atomic Energy Agency. As nuclear submarines require enriched uranium, Brazil could disguise its submarine development as a means to develop nuclear weapons.
Existential deterrence -- the product of a mode of thought that emphasizes military capabilities over diplomacy and rhetoric -- has, in the nuclear age, been acclaimed by many states as a strategic necessity. As has been stated: "Potential opponents would be expected to draw conclusions about the capacity and will which would inform their own posture and actions." Brazil therefore asserts its nuclear powered submarines as a peaceful deterrent and not a weapon of war.
Since the Cold War era, common belief has held that mutual assured destruction ["MAD",] especially with a stated policy of "no first use," can be strengthened with the deployment of nuclear-powered submarines. Brazil may well determine that if it acquires nuclear capability, at least some of its weapons could survive an enemy's first strike and thereby deter further attempts at aggression.
By stating that submarines would be used for defensive roles only, Brazil apparently tries to make clear, as the analyst William Goncalvez stated, that it has "strategic needs," but no desire to fuel an "arms race….nor does it want to be a military power."
At a time when countries such as China, Russia, and Iran are intensifying their efforts to deny to their adversaries access to certain areas, Brazil's nuclear-powered submarines could also enable the country to enhance its sea-denial capabilities. Brazil's nuclear-powered submarine is expected to have a "world wide reach, deep water stealth, and strike capability." The submarine could further be used for finding and tracking enemy submarines and to carry out covert missions for intelligence gathering.
The cost of building the fleet of submarines would be high, estimated up to USD $4 billion. As such, Brazil's domestic problems might cause a reduction to its defense budget. Moreover, the Brazilian navy has had an uneven experience with its French Sao Paulo aircraft carrier which, when deployed, has undergone a number of mechanical problems.
Brazil's submarine capabilities could, of course, enable it to take part in warfare away from Brazil's borders. When under the threat of nuclear war, having the capability to wage a war distant from the homefront is advantageous. Although, under the Treaty of Tlalelolco of 1967, Latin America is at present is a nuclear-weapons-free zone, Brazil's move towards nuclearization could prompt Venezuela and Argentina to follow suit.
Brazil could also eventually develop SSBNs(ship-submersible ballistic missile nuclear-powered submarines), which can fire submarine-launched ballistic missiles, and which are one of the components of a nuclear triad -- to move towards a credible deterrent. Brazil could choose to develop submarine-launched missiles or torpedoes. In the long run, the nuclear attack submarines could be converted to submarines capable of carrying nuclear-capable cruise missiles. Only then can Brazil strengthen its Continuous-at-Sea Deterrent, or the ability of a submarine armed with nuclear missiles to be on constant patrol.
These nuclear developments in Brazil are worth watching closely: the precariousness of deterrence, or of collapsed or ineffective deterrence, easily leads to all-out war.
Debalina Ghoshal is an Associate Fellow at the Centre for Air Power Studies, Western Air Command, New Delhi, India.
 "Brazil to build first nuclear submarines", Xinhua News, March 2, 2013.
 "Brazil to build nuclear submarines which will dramatically alter balance of power in South America", Mail Online, July 19, 2013.
 Fabiana Frayssinet, "Brazil's new nuclear subs to defend oil fields", AL JAZEERA, July 23, 2011.
 Serener Kelleher-Vergantini, "Brazil Moves Toward Nuclear Submarine", ARMS CONTROL ASSOCIATION, April 2013.
 At present, Brazil fields the SSK Tikuna and SSK Tupi class SSKs. SSKs are conventional attack submarines. In the United States, the Navy used SS to classify that the vessel was a submarine (and K was to denote the submarine was a hunter killer. SSK was the hull classification symbol of the United States' Navy.
 NOTE: Since oil reserves have been discovered in the Falkland Islands, further tensions have risen in the region.
 Note: Brazil's partner has been France DCNS (Direction Technique des Constructions Navales) and Brazil's Odebrecht -- as well as Spain, albeit with French enhancements.
"Brazil & France in Deal for SSKs, SSN", DEFENSE INDUSTRY DAILY, April 11, 2013.
 Anthony Boadle, UPDATE 1- Brazil launches program to build nuclear submarine in a decade", REUTERS, March 1, 2013.
 Vijay Sakhuja, "Sea Based Deterrence and Indian Security", IDSA,
 Ambassador Taylor was Foreign Service officer and navy veteran.
 Paul D. Taylor, "Why Does Brazil Need Nuclear Submarine?", U.S. Naval Institute, June 2009, Vol. 135/6/1,276.
 Brazil Submarine Capabilities, Nuclear Threat Initiative, July 18, 2013.
 Fabiana, n.3.
 "Brazil To Get Its First Nuclear Submarine", Defense News, March 2, 2013.
 Fabiana, n.3.
 SSK Scorpene Class Attack Submarine, France, naval-technology.com
Brazil launches program to build nuclear submarine in a decade, n.8.
 Greg Thielmann, Wyatt Hoffman, "Submarine Nuclear Reactors: A Worsening Proliferation Challenge", Arms Control Association, July 26, 2012.
 Michael Codner, "DEFINING DETERRENCE: Framing Deterrence in the 21st Century", May 18th-19th, 2009.
 Fabiana Frayssinet, n.8.
 It is a naval concept in which states develop military build up at sea in order to prevent the military dominance of another power in a particular region.
 "Brazil builds fleet to parade military on world stage", WORLD REVIEW