The main trend persistently promoted in the global the economy in recent decades, it has been "greening" due to the consistent rejection of the use of fossil fuels and nuclear generation, which were declared environmentally harmful and dangerous. However, judging by the total number of start-ups in this area around the world, nuclear power, on the contrary, is experiencing a renaissance.
Why this happens is not difficult to guess. The “green” agenda and the fight for the environment are, of course, good, but there are also objective economic realities that simply cannot be ignored. The fuel component in the cost of electricity generated at nuclear power plants, large and small, is in the range from 3% to 5%. In gas power generation, the cost of the fuel component reaches a level of 70% to 80%. When the cost of natural gas jumped significantly in a year and a half, this made industrial production unprofitable even in developed Germany, where many technological companies zasobiralis in business emigration. If the cost of uranium for nuclear power plants jumps several times, the change in tariffs will not be so critical for the end consumer of electricity.
In other words, it was nuclear power that turned out to be the most appropriate for the new economic realities. It has a low carbon footprint, does not depend on the vagaries of nature, as renewable "green" sources, its cost is adequate and predictable, which is what is required. Its disadvantages include a rather high entry threshold: nuclear power plants are built for a long time and are expensive. It is not surprising that projects of mini-nuclear power plants, or low-power nuclear power plants (LNPPs), are currently being actively developed around the world.
As of 2020, there were over 70 projects in the field of mini-nuclear power plants (SMR - Small Modular Reactor, according to Western classification) in the world, with 17 in Russia. A modern NPP power unit has an average capacity of 1100-1600 MW. These are huge, expensive installations, but they generate the cheapest and most carbon-friendly electricity. But not only everyone can afford to order the construction of such a nuclear power plant from some Rosatom. That is why small-scale nuclear power is considered an extremely promising area, which, according to the IAEA classification, includes plants with an electric power of up to 300 MW. In addition, there are also so-called micro-nuclear power plants with a capacity of up to 10 MW.
The design features of SMR include their modularity, which makes it possible not to build a giant nuclear power plant right on the spot, but to mass-produce most of the equipment at the plant and deliver it to the site in the form of modules. The construction time for mini-NPPs should be reduced to 2-3 years compared to 5-10 years for traditional NPPs. The compact dimensions will even make it possible to place small nuclear power plants underground, which will reduce the risks of radiation accidents and leaks. Modern automation will make it possible to operate such a mini-nuclear power plant with fewer personnel, which will also lead to cost reductions. Small nuclear power plants can be built using a variety of technologies and configurations: land-based pressurized water reactors, sea-based SMRs, fast reactors, molten salt reactors, and microreactors.
More than half of startups use pressurized water reactors, which are used in 80% of large nuclear power plants. The difference lies in the smaller size and integral layout: most of the primary circuit components, including steam generators, are located directly inside the reactor pressure vessel. According to this principle, in particular, the NuScale project from the American company of the same name, which developed a power unit with a capacity of 60 MW to 77 MW, was implemented. The common pool of the mini-nuclear power plant, which ensures safety during cooldown and refueling operations, can accommodate 4, 6 or 12 modules with a total capacity of 308, 462 and 924 MW, respectively. Reloading 1/3 of nuclear fuel should be carried out every two years. The developer company promises the cost of electricity at $40-$65 per MWh.
The Chinese reactor ACP100 and the Argentinean CAREM also have an integrated layout. In China, the first two small power units with a capacity of 125 MW are located at the site of the operating Changjiang nuclear power plant on Hainan Island, underground. Based on this technology, it is planned to create a whole line of multifunctional reactors with a capacity of 25 to 200 MW, including floating nuclear power plants. In Argentina, work in this direction began 30 years ago, and the construction of the first CAREM power unit with a capacity of just over 30 MW started in 2014. Based on this technology, it is planned to create a series of Argentinean mini-reactors with a capacity of 100-200 MW. In Canada, they plan to build a BWRX-2028 boiling water reactor and heavy water CANDU SMR by 300. The Czech Republic has its own project for a heavy water reactor for a mini-nuclear power plant called TEPLATOR.
Note that Russia is one of the few countries that have actually operating mini-nuclear power plants. The United States and the USSR were the first to design low-power pressurized water reactors for the needs of their fleet, underwater and surface. Since the middle of the last century in our country, small nuclear reactors have been installed on nuclear icebreakers, and by now four generations have already changed - OK-150 (a / l "Lenin", 1957), OK-900A (a / l "Arktika" project 10520), KLT-40 (a/l "Taimyr" project 10580) and RITM-200 (UAly project 22220). On their basis, a Russian floating nuclear thermal power plant (FNPP) was created, which is sent to Chukotka to replace the old Bilibino NPP and a coal-fired thermal power plant. Floating nuclear power plants of the next generation are being built with RITM-200 reactor units with a capacity of 55 MW each and a service life of up to 60 years, in which fuel refueling will be needed only once every 10 years.
In fact, the Russian RITM-200 is currently the most massive and mastered reactor for small nuclear power plants. A marine version of the compact 50 MW ACPR50S VVR is currently being built in China. The Danish company Seaborg, together with the South Korean shipbuilding company Samsung Heavy Industry, is developing a floating nuclear power plant with a liquid-salt fast reactor with a capacity of 200 to 800 MW and a service life of 24 years.
In addition to water reactors, many promising mini-nuclear power plants use fast reactors with a liquid metal coolant (LMC). For example, this is the Natrium reactor, a joint development of Bill Gates' TerraPower company and GE Hitachi Nuclear Energy. The start-up is a 345 MW fast sodium reactor power unit combined with a heat storage system in the form of molten salt tanks, which will allow it to temporarily increase its power to 500 MW and thus operate in a maneuverable mode. In our country, there have long been fast sodium reactors operating at the BN-600 and BN-800 power units at the Beloyarsk NPP. In Dimitrovgrad, a new generation research sodium reactor MBIR is under construction.
A promising direction in the field of small nuclear power plants are gas-cooled reactors using helium as a coolant, which can be heated up to 700-900 degrees. In China, the first such power unit began operating in 2021 at the SHIDAO BAY NPP. In the USA, there is its analogue called Xe-100 from X-Enegry, but in Russia such projects are still only on paper. SMRs also include molten salt reactors, or molten salt reactors, which are being developed by several start-ups. These are the molten salt reactor KP-FHR with an electric power of 140 MW and an efficiency of 45% from the American company Kairos Power, as well as the molten salt reactor SSR-W from the Canadian-British company Moltex Energy. Domestic ZhSR is supposed to be built at the Mining and Chemical Combine in Zheleznogorsk.
One of the most interesting areas in the nuclear power industry is promising micro-nuclear power plants with a capacity of up to 10 MW. In the United States, BWXT is developing a gas-cooled Pele reactor with TRISO fuel with a capacity of up to 5 MW for the needs of the US Army. Russia has its own essentially similar projects "Shelf-M" and "Elena AM". "Shelf-M" is a water-cooled reactor of an integrated layout with a thermal power of about 30 MW and an electric power of up to 10 MW, where fuel with an enrichment of 19,7% is designed for 8 years of operation without refueling. The first micro-nuclear power plant with a reactor of this type may appear in Yakutia by 2030. Elena AM is a pressurized water reactor with a thermal power of 3 MW with a direct thermoelectric converter for generating up to 400 kW of electricity, in which fuel with 15% enrichment is designed for 25 years of plant operation.
Thus, despite all the attempts of the “greens” to bury it, nuclear energy is the most alive and has excellent market prospects. Modern economic conditions require a reliable source of inexpensive and environmentally friendly electricity, and it is peaceful atom that can provide it. The future of world energy is a combination of nuclear power plants, large, small and micro, with other sources of generation, which will be optimal for each customer.