| Sub-family | Status | Potential gain (upside) | Risks (downside) |
| PWR | Proven, but seen as too risky. Economic feasibility requires nominal powers above 200 MW | Use of solutions to boost reactivity could remove the need of enrichment, giving a 1% - 2% cost reduction in energy tariff | Deuterated metals under high neutron flux may generate neutron absorbing elements. It is possible pulsed neutron sources with the required output would be too expensive to build and operate |
| MSR | Not proven, could be so risky as PWR. Economic feasibility requires nominal powers above 40 MW | Use of solutions to boost reactivity could remove the need of enrichment, giving a 3% - 5% cost reduction, radioactive waste burning at low cost | Deuterated metals under high neutron flux may generate neutron absorbing elements. It is possible pulsed neutron sources with the required output would be too expensive to build and operate |
| LMR | Not proven, navies saw it as riskier than PWR. Economic feasibility requires nominal powers above 40 MW | Use of solutions to boost reactivity could remove the need of enrichment, giving a 3% - 5% cost reduction, radioactive waste burning at low cost | Recent advances did not solve fundamental problems in LMR design, like corrosion along leakages and plugging (lead-bismuth) and explosion risks (sodium), besides the risk of ruptures in steam generator causing ruptures in reactor vessel. The risks of solutions for reactivity boost also apply |
| Magnetic and Inertial | Not demonstrated yet, so it is impossible to compare to fossil fuels | New super magnets along mix of magnetic and inertial confinements on deuterated or tritiated metal pellet could improve COP in orders of size. Further, the use of plasmoids could greatly simplify designs and reduce costs | Insertion of solids increases design complexity and number of possible reaction products, possibly generating radioactive waste. Plasmoids are not well understood yet and may need revision of plasma physics to be fully explored |
| Lattice | Startups and scientists claimed successful prototypes demonstrations with COP over unity | One order of size in energy costs reduction, compared to fossil fuels. The combination with pulsed neutron sources could improve reaction control | The claimed COP may be not practical in real life situations or reaction control may be impossible |