5 ms·

Can someone correct me if I'm wrong but I remember one of the reasons the RMBK reactor is so large was because there are efficiency gains with a large reactor (

Can someone correct me if I'm wrong but I remember one of the reasons the RMBK reactor is so large was because there are efficiency gains with a large reactor (among other reasons you lose fast neutrons at a higher rate in a smaller volume right?). How do these small modular reactors get around this?

thehappypm 4y ago
With nuclear, efficiency really doesn’t matter that much. It’s not the cost of the fuel that matters almost at all, it’s the cost of the reactor itself. The cost of the fuel and the efficiency of using that fuel is really a secondary cost compared to building the reactor in the first place, and operating the reactor with people
- coding123 4y ago
  The insurance required is a big one: https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/nuclear-insurance.html https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/n...
  - Krasnol 4y ago
    > Claims resulting from nuclear accidents are covered under Price-Anderson; for that reason, all U.S. property and liability insurance policies exclude nuclear accidents. Claims can include any incident (including those caused by theft or sabotage) in transporting nuclear fuel to a reactor site, storing nuclear fuel or waste at a site; during operation of a reactor, including the discharge of radioactive effluent; and transporting irradiated nuclear fuel and nuclear waste from the reactor. https://en.wikipedia.org/wiki/Price%E2%80%93Anderson_Nuclear_Industries_Indemnity_Act https://en.wikipedia.org/wiki/Price%E2%80%93Anderson_Nuclear... > The Act establishes a no fault insurance-type system in which the first approximately $15 billion (as of 2021) is industry-funded as described in the Act. Any claims above the $12.6 billion would be covered by a Congressional mandate to retroactively increase nuclear utility liability or would be covered by the federal government. Interesting.
marcosdumay 4y ago
Yes, neutron economics permit the use of poorer fuel on a larger reactor. That saves on the enrichment. A larger reactor also gains efficiency on the power generator. Larger turbines are cheaper by power than smaller ones.
- stjohnswarts 4y ago
  i thought fuel cost for nuclear was a teeny tiny part of the cost and maintenance, safety, day to day operations were the real money sink. So why does a bit more cost matter even if it's 10x?
  - marcosdumay 4y ago
    Personally, I have no idea. Smaller reactors have larger fuel costs, and some mixed results on investment costs. The also have as simplified operation. I have no idea what side the net result turns on. Anyway, the one thing that I know is that a really large share of their initial costs comes from the small scale they are built. If smaller reactors work commercially, the costs may become more similar to coal.

thehappypm 4y ago

With nuclear, efficiency really doesn’t matter that much. It’s not the cost of the fuel that matters almost at all, it’s the cost of the reactor itself. The cost of the fuel and the efficiency of using that fuel is really a secondary cost compared to building the reactor in the first place, and operating the reactor with people

coding123 4y ago
The insurance required is a big one: https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/nuclear-insurance.html https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/n...
- Krasnol 4y ago
  > Claims resulting from nuclear accidents are covered under Price-Anderson; for that reason, all U.S. property and liability insurance policies exclude nuclear accidents. Claims can include any incident (including those caused by theft or sabotage) in transporting nuclear fuel to a reactor site, storing nuclear fuel or waste at a site; during operation of a reactor, including the discharge of radioactive effluent; and transporting irradiated nuclear fuel and nuclear waste from the reactor. https://en.wikipedia.org/wiki/Price%E2%80%93Anderson_Nuclear_Industries_Indemnity_Act https://en.wikipedia.org/wiki/Price%E2%80%93Anderson_Nuclear... > The Act establishes a no fault insurance-type system in which the first approximately $15 billion (as of 2021) is industry-funded as described in the Act. Any claims above the $12.6 billion would be covered by a Congressional mandate to retroactively increase nuclear utility liability or would be covered by the federal government. Interesting.

marcosdumay 4y ago

Yes, neutron economics permit the use of poorer fuel on a larger reactor. That saves on the enrichment. A larger reactor also gains efficiency on the power generator. Larger turbines are cheaper by power than smaller ones.

stjohnswarts 4y ago
i thought fuel cost for nuclear was a teeny tiny part of the cost and maintenance, safety, day to day operations were the real money sink. So why does a bit more cost matter even if it's 10x?
- marcosdumay 4y ago
  Personally, I have no idea. Smaller reactors have larger fuel costs, and some mixed results on investment costs. The also have as simplified operation. I have no idea what side the net result turns on. Anyway, the one thing that I know is that a really large share of their initial costs comes from the small scale they are built. If smaller reactors work commercially, the costs may become more similar to coal.