Why not nuclear power?

[Bearware]

16. Sorry, you are correct I poorly stated the reasons for massive containment buildings.

In PWR (pressurized water reactor) the size and strength of the containment buildings has to be able to handle steam explosions, hydrogen explosions and potential radiation leaks. Molten Salt Reactors do not need to have solid fuel or water cooling of the core so steam or hydrogen explosions do not happen in the core. Radiation leaks are possible but would not be spread by explosions and would be mostly contained chemically in the molten salt which would quickly freeze outside of the reactor.

My favorite MSFR (Molten Salt Fast Reactor) design uses sodium chloride (NaCl) molten salt with an outlet temperature of 600 C (1111 F) and inlet of 500 C (900 F). It uses standard nuclear certified stainless steel piping which limits the temperature range they can use. In the future when certified higher temperature piping is available this will probably increase. This design does not need the large pressure differential in some existing reactors as water is not used as a coolant for the reactor (molten salt is) and non-radioactive molten salt from a heat exchanger is sent to produce steam for a Rankine cycle or later potentially CO2 for a Brayton cycle when it is shown to be reliable.

A PWR needs a strong containment for a large-break LOCA (Loss of Coolant). The MSFR above uses molten salt as a coolant and fuel carrier. A large break in a line would spill molten salt on the floor which would quickly solidify. If there was a large break in a fuel line the reactor would automatically shutdown due to loss of criticality. The reactor is always barely critical. If the reactor overheats the fuel is automatically drained into tanks that will not support criticality and stop the reactions even if all power is lost. The drain tanks can air cool without problems.

The reactor design in question has a conservative design to make it able to be certified today with existing certified materials. In the future with better materials it could go to higher temperatures and potentially use dry cooling towers.

The reactor vessel itself is about 4 meters in diameter and will fit in a standard freight truck trailer for transport on regular highways.

I do not have a background in nuclear but am really impressed with the above design because it has clearly been thought out by a group with long time experience in nuclear energy. Instead of reaching for maximum numbers they are working with what will likely get their reactor certified now and maintain the substantial advantages of molten salt fuel and molten salt coolant. As more advanced materials become certified they can take advantage of many of them without major changes.

Here are two video's on the MSFR I am talking about above. Notice the evolution in the design from one video to the next. Since you were in the Navy you might have met the speaker.