> …, and have a robust system that can safely shut down with concern about meltdown
Do you mean ‘without’?
The shell prevents the release of radioactive materials, so TRISO fuel encapsulation would turn a melt down into a reactor damaging event rather than an emergency/crisis. A runaway reactor would get hot, melt its structure, and maybe drop parts inside its containment, but the fuel wouldn't melt and wouldn't travel far. Most likely the reaction would stop as soon as the structure of the core fell apart.
I was going to make a top level comment along the lines of:
"How thick/expensive a bunker would one need to build around one of these to prevent it from spreading radioactive materials about when hit by say, an airplane?
As I understand it, large legacy reactors are hardened for this. Would the same level of safety still allow these smaller reactors to be economically viable?"
But now that I have read your comment, would a kinetic event happening to a TRISO fueled reactor be more of a non-event? Follow up, would non-fuel components of the reactor become radioactive over time as well?
Sorry if dumb questions, not very educated in this space.
Mechanical coolant pumps were the Achilles heel of the infamous Sodium Reactor Experiment (SRE) from 1957-64 at Santa Susana field laboratory. It had 50,000 lbs of liquid sodium in two coolant loops.
When 4 pints of tetralin leaked from a pump seal into molten sodium surrounding the SRE reactor core (500-950F), it fouled the fuel cladding with “brown stuff” and various fission products from the melted rods were found on both sides of the fence. [1]
A “small amount of sodium” in sealed heat pipes sounds pretty safe. But since Westinghouse filed all the eVinci’s NRC pre-application materials as “proprietary”, the actual design details aren’t available to the public for review.
“Disruption” I assume refers to hundreds of rule exemptions (licensing innovations) they filed as a non-LWR. Not judging, just stating the record. [2]
1. https://www.etec.energy.gov/Library/Main/Doc._No._1_SRE_Fuel...
2. https://www.nrc.gov/reactors/new-reactors/advanced/licensing...
Yeah, install a nuclear reactor at a remote mining site, probably without sufficiently trained personnel to take care of it. What could go wrong?
Just one example - the Nevada Test and Training Range alone is a bit over 4,500 square miles.
https://en.m.wikipedia.org/wiki/Nevada_Test_and_Training_Ran...
Vs. Wikipedia says the entire U.S. Army (active duty) has ~485,000 personnel.
Divide...and that's ~0.17 Army people per acre, even if the US Army had NO job except holding down the NTTR. (Which is actually US Air Force, BTW.)
[Edit: But +1 - because in the bigger picture you make a valid point. However vast the open spaces, at the spots where the cool & expensive stuff sits, there does have to be some sort of "real" security. If only so dodgy locals don't swing by with a pair of bolt cutters, and start helping themselves.]
Very realistic scenario if the thing is used in a war zone.
> "The microreactor can generate 5 MW of electricity or 13 MW of heat from a 15 MW thermal core. Exhaust heat from the power conversion system can be used for district heating applications or low-temperature steam."
Control systems are kind of interesting:
> "The only moving or mechanical parts in the reactor system are reactivity control drums, which manage the power level and allow absorber material to passively turn inward toward the core if power demand is reduced or lost, and turn a reflector material toward the core if demand increases automatically. Hence the term “nuclear battery.”"
I'm generally not a nuclear advocate but if they've really managed to eliminate the need for active cooling, and have a robust system that can safely shut down with concerns about meltdown even without external power, that's a pretty big advance. Looks remarkably promising... keep your fingers crossed. (New nuclear tech hasn't had the greatest track record over the past several decades, i.e. pebble beds didn't work out etc.)