Nuclear power has revolutionized the way ships and submarines operate, allowing them to stay at sea for extended periods of time without the need to refuel. Thanks to research conducted by the U. S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI), nuclear power plants are now capable of producing clean, reliable energy for up to 80 years.
Seven plants (15 reactors) have already submitted subsequent license renewal applications (SLR) and more are expected as more reactors approach the end of their operating licenses. The DOE, EPRI, NRC and other stakeholders identified a list of key materials and parts used in the plants, ranging from the reactor core (and much of the equipment inside) to the wiring and concrete around the plant. They then measured the performance of each material to determine how they perform over time. Most of these materials meet the desired performance standards expected for long term operation.
Materials that did show normal signs of aging and degradation were identified so that plants could proactively monitor and maintain them over time. Turkey Point Units 3 and 4 are the first reactors authorized by the NRC to operate for up to 80 years. Fifteen reactors are already using this research to request a second 20-year extension. Xcel Energy is also considering submitting applications for reactors in its fleet. To date, 20 reactors, representing more than a fifth of the national fleet, are planning or intend to operate for up to 80 years. Nuclear power generates nearly 778 billion kilowatt hours of electricity each year and accounts for more than half of the country's clean energy.
It operates at full power more than 92% of the time and has provided approximately one-fifth of the nation's energy since the mid-1990s. The loss of these reactors would ultimately reduce America's large-scale supply of affordable and reliable clean energy, as well as deplete the experience, knowledge, and supply chain that accompany the entire U. S. In addition to materials research, the LWRS program is working on modernizing plant systems to reduce operating and maintenance costs, while seeking to diversify plant products through non-electrical applications, such as desalination and energy for hydrogen production. The propulsion plant of a nuclear-powered ship or submarine uses a nuclear reactor to generate heat.
The heat comes from the fission of the nuclear fuel contained in the reactor. Since the fission process also produces radiation, shields are placed around the reactor to protect the crew. A great advantage of nuclear-powered submarines is that they do not require refueling. When one of them comes into service, enough uranium fuel will be put into service to last more than 30 years. They will have an S1B nuclear reactor with electric drive (without reduction gears) and pump jet propulsion.
Nautilus led to the parallel development of other Skate-class submarines, powered by individual pressurized water jets (PWR), and an aircraft carrier, the USS Enterprise, powered by eight PWR units in 1960. Two PWR VM-5s, each 190 MWt and 37 MW of axle, powered the third-generation SSBN vessels, with a single unit in the SSN. That means nuclear submarines can remain submerged at deep depths for months at a time, giving them better stealth capabilities and allowing longer and more remote deployments. The Soviet icebreaker Lenin was the world's first nuclear-powered surface vessel in 1959 and remained in service for 30 years (new reactors were installed in 1970). For uranium to be designated as “weapons grade”, it needs to be enriched to 90% uranium-235; fuel for a nuclear-powered submarine does not come close. Work on marine nuclear propulsion began in the 1940s, and the first test reactor was launched in the United States in 1953. Large ballistic missile submarines (SSBNs) and cruise missile submarines have two of them with steam turbines together that deliver 74 MW, and their third attack submarines generation (SSN) have a single VM-5 plus OK-650 unit that powers a 32 MW steam turbine. The Naval Reactor program has demonstrated to the world that nuclear energy can be managed safely, without adverse effects on the public or the environment.
This will include nuclear propulsion, floating nuclear power plants, small modular offshore reactors used for hydrogen production and maritime transport of SMR. The United States Navy's Nautilus 1955 had a 93% fuel-enriched PWR S2W, a core life of 900 hours at full power, and a shaft power of 10 MW. A more powerful icebreaker of 110 MW net and 55,600 deadweight tons is planned, with additional double-draft ships of 32,400 TPM and 60 MW of power. The power levels required to break ice up to 3 m thick, along with refueling difficulties for other types of vessels, are important factors. The study indicated that certain routes and loads lent themselves well to the nuclear propulsion option, and that technological advances in the design and manufacture of the reactor had made the option more attractive. By 1990, there were more nuclear reactors powering ships (mostly military) than those generating electrical power in commercial power plants around the world.