Rohani's Order for Nuclear Propulsion in Commercial Ships

Recently, Hassan Rouhani, the President of Iran, in response to the ten-year extension of U.S. sanctions against Iran (ISA), issued an order to Ali Akbar Salehi, the head of the Atomic Energy Organization, to collaborate with the country's scientific and research centers to design and produce a nuclear propulsion system for use in maritime transportation. Rouhani mandated that Salehi present a scheduled plan for implementing the provisions of this order within a maximum of three months. Four years ago, in June 2012, amidst Iran's nuclear issues during Mahmoud Ahmadinejad's presidency, which saw tensions between the Islamic Republic and Western countries peak, Admiral Abbas Zamini, the technical deputy of the Navy, stated, "Iran is in the early stages of constructing a nuclear submarine." At that time, Admiral Gholamreza Khadem Biqham, the deputy commander of the Navy, discussed the use of nuclear fuel for Iran's ships and submarines, asserting, "This technology exists in the country, and if we are to build larger ships with longer lifespans at sea, we need better and more reliable fuels... and this capability exists in the country to create this propulsion system for ships." Rouhani's order and the statements of the mentioned officers raise several questions, including what nuclear propulsion in ships entails, whether using nuclear propulsion in commercial ships is economically viable, how this type of propulsion system applies to naval vessels, whether Iran is capable of constructing a nuclear submarine, and whether Iran can build a nuclear propulsion system specifically for ships. Nuclear propulsion in ships, submarines, and aircraft carriers relies on one or two nuclear reactors, which are significantly smaller than land-based reactors. In nuclear propulsion, the heat generated from the energy produced by the reactor is used to create steam, which in turn drives steam turbines or turbo generators. The resulting power is transmitted to the gearbox, ultimately transferring the mechanical energy produced to the ship's or submarine's propeller(s), enabling their movement. While the Iranian president has issued an order for the construction of nuclear-powered ships, international sanctions and the dire economic situation of the Islamic Republic have driven many industries, including Iran's shipbuilding sector, towards closure. Recently, the Islamic Republic signed a $2.4 billion agreement with a South Korean shipbuilding company to construct ten tankers and at least six small ships. The navies of Russia, the U.S., and the U.K. primarily use steam turbines for propulsion systems, while China and France generate electricity using steam turbines, which is then converted into mechanical power for moving vessels or submarines (the turboelectric system). In recent decades, the installation of nuclear reactors on commercial ships has been largely experimental or for gaining experience. In this regard, the U.S. built the "Savannah" for the first time in 1962 but ultimately abandoned its use as a commercial ship due to cost inefficiency. Germany also constructed a nuclear cargo ship in 1960 but had to replace its propulsion system with diesel engines in 1979 due to rising maintenance costs. Japan built a ship named "Matsu," but due to multiple technical issues that later arose, the project for using nuclear commercial ships was abandoned. Russia is the only country with a commercial icebreaker that has been in use in Arctic waters since 1988. In addition to this ship, Russia has built nine nuclear icebreakers over the past five decades, six of which are still operational. In naval operations, nuclear reactors are primarily used for the propulsion of strategic submarines known as nuclear submarines and aircraft carriers. These submarines, generally equipped with ballistic and cruise missiles with nuclear warheads, are considered crucial tools of nuclear deterrence. Utilizing the mentioned propulsion system, these submarines can remain submerged for weeks without needing to surface, continuing their patrols. Their stealth prevents enemies from tracking and locating them, as well as preemptively attacking, thereby ensuring the principle of "mutual destruction" in a nuclear war. The experiences of the U.S., Germany, and Japan have shown that using nuclear propulsion in commercial ships is not economically viable concerning maintenance costs. Insurance for such ships will be significantly high due to the risk of nuclear incidents, especially in foreign ports. The mentioned submarines do not require refueling for years, sometimes for their entire lifespan. However, due to the extremely high costs of building these submarines and nuclear technology, only six countries— the U.S., Russia, the U.K., France, China, and India— with strategic naval forces utilize these submarines. Nuclear propulsion is commonly used in most aircraft carriers, which are essentially floating airbases. The aforementioned countries utilize these carriers, with the U.S. possessing ten of them. Rouhani's order for constructing nuclear-powered ships comes at a time when international sanctions and the dire economic situation of the Islamic Republic have driven many industries, including Iran's shipbuilding sector, towards closure. Recently, the Islamic Republic signed a $2.4 billion agreement with a South Korean shipbuilding company to construct ten tankers and at least six small ships. Regarding the construction of nuclear submarines, which some naval commanders have claimed, the Islamic Republic is still in the process of building a 600-ton Fateh-class submarine, apart from constructing midjet submarines. The experiences of the U.S., Germany, and Japan have shown that using nuclear propulsion in commercial ships is not economically viable concerning maintenance costs. Insurance for such ships will be significantly high due to the risk of nuclear incidents, especially in foreign ports. The reactors for ships differ significantly from land-based power-generating reactors. Given the space limitations in these vessels, the reactors for these units are physically smaller compared to land-based reactors, and their power output does not exceed a few hundred megawatts. The mechanical systems of these reactors must be highly precise and flawless to withstand rolling, pitching, vibrations, shocks, stress, and generally rough seas. Additionally, the fuel concentration in marine reactors is higher than that of land-based reactors. Some countries use low-concentration fuel for their marine reactors, resulting in more frequent refueling for ships with such reactors. Several countries also use high-concentration uranium ranging from 20% to 96%, especially in strategic submarines, allowing these underwater units to remain submerged for extended periods without the need for frequent refueling. While constructing a marine nuclear reactor, as the U.S. State Department spokesperson stated, does not violate the JCPOA, there is currently no indication that Iranian nuclear scientists are familiar with designing or constructing such a reactor or that they could build one in the near future. Rouhani's order for constructing this reactor, even if the capability exists in the country, is neither economically justifiable nor practical for commercial ships, nor does it represent a measured response to the extension of U.S. sanctions against Iran.