The definition of nuclear submarine is very clear, it refers to a submarine using nuclear power. If a country wants to build a strong strategic navy, it must have at least two important weapons, namely aircraft carriers and nuclear submarines. Currently, there are far more countries in the world that have aircraft carriers than nuclear submarines, because it is much more difficult to build a nuclear submarine than an aircraft carrier, both in terms of R&D and construction difficulty and financial investment. So far, the only countries in the world that can independently build nuclear submarines are the five permanent members of the United Nations. Another country, India, is currently working hard to develop it.
The main reason why nuclear submarines are not easy to own is R&D funding and technology. It would be very difficult for a major country to develop such an important weapon as a nuclear submarine in less than ten years. Tens of billions of dollars would have to be invested in R&D alone. This is not R&D funding that most countries can afford. The defense and military budgets of many countries for many years are only tens of billions of dollars, making it unimaginable to develop nuclear submarines. The most expensive nuclear submarine in the world is currently the Triumph-class strategic nuclear submarine that the French served at the end of the last century. The cost of this submarine at the time was 4 billion euros, which was almost equal to 40 billion yuan based on the exchange rate at that time, so it was called It is no exaggeration to say that it is the most expensive nuclear submarine currently in service.
When the newly developed fifth-generation ballistic missile nuclear submarine Columbia-class nuclear submarine in the United States enters service in the early 1930s, I am afraid that it will take away the most expensive title. The Columbia-class nuclear submarine is claimed to be the largest nuclear submarine ever built by the United States. It is 171 meters long, 13 meters wide, and has a submersible displacement of an astonishing 20,810 tons.
According to the U.S. Department of Defense, a total of 12 Columbia-class submarines will be built to replace the Ohio-class, with a total investment of 125 billion U.S. dollars. Each submarine costs approximately 12-13 billion. . Based on the current exchange rate between the US dollar and the RMB, the cost of a Columbia-class nuclear submarine is more than 80 billion yuan. If it's just expensive, that's okay, because there are always countries like Saudi Arabia that are not short of money. But another difficulty with nuclear submarines is that they are extremely technically difficult.
To be able to develop and manufacture nuclear submarines, you must be a big country. Small countries simply do not have the industrial foundation and technical capabilities. First of all, we must be able to manufacture a submarine pressure-resistant shell with very high strength, which must be able to withstand the huge pressure of at least 600MPA. This requires steel with extremely high strength. In fact, the manufacturing process and level of steel can represent the level of a country's heavy industry.
Only with good steel can it be possible to manufacture the shell of a submarine. This is the first step in the long march. Countries that are not even capable of manufacturing shells should give up this idea as soon as possible. In addition to the need for special steel, another difficult point is the nuclear power issue of the submarine itself. The biggest feature of nuclear submarines is that they rely on the power generated by nuclear fuel, so it is necessary to at least be able to build a nuclear power plant on land, and then miniaturize it and then move it to a nuclear submarine.
How to miniaturize is a difficult problem. Also, where does the fuel for refueling come from? In order to improve efficiency, nuclear submarine reactors usually use high-abundance nuclear fuel. The U.S. Navy uses 97% weapons-grade nuclear fuel. This high-abundance enriched uranium can directly make nuclear weapons. The nuclear fuel abundance of nuclear submarines in Russia, Britain, France and other countries is between 25 and 40%. This kind of high-purity nuclear fuel for military use is almost nowhere to be purchased, and countries such as the United States and Russia do not have enough.
The abundance of low-enriched uranium nuclear fuel in civilian nuclear power plants does not exceed 3%. In this case, you can only extract it yourself. If you build thousands of centrifuges to work together for several years, you may be able to extract the required nuclear fuel. But this process is too difficult, and countries without strength simply cannot do it. In addition to the above, there are many difficulties and problems in building nuclear submarines. In short, nuclear submarines are not easy to develop and build. This is the patent of big countries and cannot be used by small countries.