Despite Obama: A Slow Revival of US Nuclear Power?

The article excerpted below is a summary and description of a recent report from the Federation of American Scientists: The Future of Nuclear Power in the US (PDF). The FAS report is something of a "good news, bad news" joke: The good news is that a lot of safe new nuclear reactors are being designed and developed; The bad news is that the US government may not allow them to be built. Read on:

Generation III reactors were designed as improvements to those currently operating in the US, emphasizing simplification, standardization, and passive safety features. However, after the Three Mile Island and Chernobyl accidents, no Generation III plants were ever constructed. More recently, updated versions of these designs (known as Generation III+) were developed, and are in the process of being licensed. The recently approved Westinghouse AP-1000 is one such example.

The next generation of commercial reactors, Generation IV, are all still in the research and design phase, but promise significantly higher performance, safety features, and sustainability. The development of Generation IV reactors began in the US in 2000, but since then 12 additional countries joined in the research program.


There are six specific reactor concepts that fall in this category: Very High-Temperature Reactor (VHTR), Super-Critical Water-cooled Reactor (SCWR), Molten Salt Reactor (MSR), Sodium-cooled Fast Reactor (SFR), Lead-cooled Fast Reactor (LFR), and Gas-cooled Fast Reactor (GFR). The first three are thermal reactors that operate at high temperatures, providing heat for non-electricity purposes. The second three are fast reactors that could function as breeders or nuclear waste burners.

...The VHTR is designed to operate at temperatures as high as 1000°C in order to provide the heat needed for industrial processes such as steam reforming of natural gas, coal gasification, and hydrogen production via the sulfur-iodine cycle. This would allow the reactor to serve as a source of both electricity and alternative liquid fuels. However, conventional light water reactors are limited by the boiling point of water, so instead coolants such as gases, supercritical water, or molten salt must be used to reach such high temperatures. In addition, new construction materials would be needed to withstand high-temperature operation.

The US actually built two prototype VHTRs using helium as the coolant: Peach Bottom 1, which operated from 1966 to 1974, and Fort St. Vrain, which operated from 1977 to 1992. Helium is used in most VHTR designs since it is inert, remains in the gas phase, and doesn’t become radioactive (unlike most other coolants). Research on helium-cooled VHTRs is ongoing, funded by the DOE Office of Nuclear Energy. The main challenges are sustained operation at such high temperatures.

...The NRC hasn’t yet approved any SMR designs, but multiple companies and research groups have been developing them since the 1970s. Designs using water, helium, sodium, lead, and fluoride salt coolants are all being considered, although the first commercial reactors will likely use the familiar light water reactor technology.

To give you an idea of the size, Westinghouse designed an SMR based on their larger AP1000 reactor. Compared with the AP1000’s 1100 MW electrical power output, the SMR would generate around 225 MW. All of the reactor components fit inside a containment vessel a little under 30 meters high and 10 meters in diameter. Like the AP1000, in includes passive safety systems. This design could remain cooled for seven days without any human intervention.

Many other companies are also designing SMRs. Babcock & Wilcox is working on a 160 MW, pressurized light water reactor design called mPower that might cost $600 million.

NuScale Power is developing an even smaller pressurized light-water SMR (creatively named NuScale) that would sit in in an underground water-filled pool. Each NuScale reactor module, at 45 by 9 meters, would generate 45 MW; a combined reactor building with 12 SMRs would generate a total of 540 MW. Unlike other designs that use pumps to circulate water, the NuScale reactor relies on natural convection.

...Another company, Hyperion Power Generation, is developing a 25 MW fast SMR that uses a lead-bismuth eutectic liquid-metal coolant (this falls in the Generation IV LFR class). Unlike most other reactors that use uranium dioxide as fuel, the Hyperion Power Module would use uranium nitride. This has a higher melting point and thermal conductivity than the typical fuel, which is beneficial at the higher operating temperatures of liquid-metal cooled fast reactors. With this SMR, instead of refueling every couple years, the entire 20-ton module is designed to be replaced every 7-10 years.

Low-cost SMRs may offer a solution to the cost problem, and help revitalize the industry. However, none have yet been approved by the NRC.

According to David Biello at Scientific American, only the two plants in Georgia plus another three elsewhere are likely to be constructed in at least the next decade. If there is a nuclear revival, it’s likely to be a slow one. _Arstechnica

The article above also links to a recent MIT report on the nuclear fuel cycle (PDF).

Clearly the two issues of new reactor technology and new fuel cycle technologies, are intertwined. The ideal reactor : fuel cycle duo would allow maximum extraction of energy from mineral ores (uranium and thorium) with minimal processing, minimal waste, minimal costs overall, and minimal risk of proliferation.

For the US to contribute to reaching that goal, it will be necessary to eject anti-nuclear bureaucrats and functionaries from the NRC with all due haste. Any politicians who are unwilling to take the necessary steps toward streamlining the path to a safer and more abundant future of nuclear power, should likewise be ejected with all due haste.