Dale said:
I can’t see the legal/regulatory issues ever making a 20 kW nuclear power plant viable
The 100 kWt (20 kWe) is a demonstration module. I would expect micro-reactors to be larger, and perhaps be used to district heating, as well as electricity. I don't know how such a plant would be scaled up with Stirling engines. An efficiency of 20% is rather poor.
It may be more of economics as it relates to design to meet legal/regulatory (safety) requirements.
https://www.nrc.gov/docs/ML2004/ML20044E249.pdf (February 5, 2020)
The U.S. Nuclear Regulatory Commission (NRC) is working to have an effective and efficient mission readiness for reactors that differ considerably from those currently licensed. Micro-reactors, that is, reactors that have a thermal power of no more than tens of megawatts, are one class of these advanced reactors. This report is to articulate the technical and regulatory issues that will need to be addressed for NRC to have the ability to review licensing applications for micro-reactors. Many of the issues center around the fact that a) these reactors may be operated remotely and/or semi-autonomously and b) it will be difficult to analyze risk from new, unique, technologies. Initial thoughts are given on how probabilistic methods could be used to determine risk and how the current approach for reviewing non-power reactors could be useful for micro-reactors.
My bold for emphasis.
https://gain.inl.gov/MicroreactorProgramTechnicalReports/Document-INL-EXT-19-55257.pdf
Key Regulatory Issues in Nuclear Microreactor Transport and Siting, INL/EXT-19-55257, September 2019
SECY-20-0093, POLICY AND LICENSING CONSIDERATIONS RELATED TO MICRO-REACTORS, October 6, 2020
https://www.nrc.gov/docs/ML2012/ML20129J985.pdf
SECY-20-0093, Enclosure 1, Technical, Licensing, and Potential Policy Issues for Micro-Reactors
https://www.nrc.gov/docs/ML2025/ML20254A365.pdf
The NRC has to give them serious consideration, IF there are interested parties willing to put up some support. Micro-reactors have been under consideration for several years, and I understand that the intent is to provide a power source to remote locations.
Nuclear Energy Institute, "Micro-Reactor Regulatory Issues," November 13, 2019
https://www.nrc.gov/docs/ML1931/ML19319C497.pdfIF at least one of the fusion concepts is viable, especially if it based on the aneutronic p-B11 reaction, then a lot of current nuclear technology could be short-lived. Then again, an industry devoted to p-B11, will be highly dependent on available B11.
https://www.usgs.gov/centers/nmic/boron-statistics-and-information
According to Statista, "As of 2020, Turkey had the largest reserves of boron globally. Turkey has an estimated 1.1 billion metric tons of boron in reserves. The United States and Russia shared the second highest boron reserves with just 40 million metric tons."
https://www.statista.com/statistics/264982/world-boron-reserves-by-major-countries/
Contrast the boron resources with uranium resources.
https://www.iaea.org/newscenter/pre...seeable-future-say-nea-and-iaea-in-new-report
The world's conventional identified uranium resources amounted to 8 070 400 tonnes of uranium metal (tU) as of 1 January 2019. These represent all reasonably assured and inferred uranium resources that could be recovered at market prices ranging from 40 to 260 USD/KgU (equivalent to 15 to 100 USD/lb U3O8).
https://www.world-nuclear.org/infor...ycle/uranium-resources/supply-of-uranium.aspx
I know of a program to extract U from seawater, among other programs.