The Evolution of Nuclear Reactors and Their Manufacturing

The development of nuclear reactors for power plants has seen significant changes over the years. Currently, most reactors are built on-site, but the future may see a shift towards modular reactors that can be manufactured in a factory setting and transported to the power plant.

One noteworthy company, ThorCon, has proposed an innovative approach using shipyards and special ships to build, deliver, and service molten salt reactors. The design of this plan is already ready for construction, marking a potential revolution in nuclear reactor manufacturing.

Current Manufacturing Practices

Many nuclear reactors are supplied by Japan Steel Works Ltd., a company renowned for their extensive foundries and forging facilities. Their Kobe facility has also been responsible for manufacturing and machining extremely large Low Pressure Turbine shafts.

While these facilities are currently meeting the needs of the industry, as the Nuclear Power industry begins to expand, they may become a bottleneck. This highlights the importance of diversifying manufacturing options and exploring innovative methods like those proposed by companies like ThorCon.

Nuclear Reactor Design and Construction

Nuclear reactors for power plants generally involve the assembly of large reactor cores. Currently, reactors are built on-site and then disassembled and reassembled every few years. A typical Pressurized Water Reactor (PWR) core consists of a couple of hundred fuel assemblies stacked side by side.

Each fuel assembly contains roughly 200 fuel rods, which are typically 12 feet long. The fuel assemblies themselves are about 8 inches across, when placed side by side. Therefore, a reactor built from these fuel assemblies would be approximately 12 feet high and 12 feet in diameter.

The reactor structure includes a bottom plate that holds the bottoms of the fuel assemblies in place and a top plate. The arrangement of fuel rods within the fuel assemblies can vary; for instance, Russian fuel assemblies use a hexagonal arrangement, while U.S. assemblies are usually square. These designs cater to different operational needs and efficiencies.