They're implying it resulted in 3x the fuel economy (20% burnup) when in reality it is half by hiding the important figures (20% enrichment rather than 3.5%, and it adds a lot of other mass to the fuel that is difficult to remove when you need to store it). So that you'll assume that the bit they didn't mention is normal rather than very unusual.
An analogue would be advertising a new car that gets 150mpg, but not mentioning the fuel it uses is a special exotic fuel not made in many existing refineries that requires 6x as much oil and you need 9 gallons of non-fuel to run through the engine for every gallon rather than 0.2.
Every single statistic nuclear proponents cite that can be easily checked in a few minutes is either technically true but designed to mislead like this one, or an outright lie. It makes it very hard to believe the things that cannot be easily checked.
In all likelihood one or more of the SMR concepts around is safe and economically viable enough to fill an important niche, but when all information they mention turns out to be lies it's kinda hard to trust.
Thank you. Yes, I think that there is still some ways to go with making these cost efficient vs other tech. I have heard people mention similar issues that you are rightly calling out. I believe the hope is the viability of these designs relies on cost reductions that would come from mass production/ economies of scale. I don't know how realistic that is, but it does tend to happen when things get produced in greater quantities, smart people find many optimisations to reduce cost.
New Uranium mining is incredibly destructive and limited. Dropping the breeding ratio to effectively zero is a non-starter.
Plus noone really know how you might make TRISO pellets not cost $40-600/MWh (or rather it costs well over $600/MWh and they think it might come down maybe) or cost $20/MWh to handle and store at the back end of the cycle (although this one might be solvable by burying the whole reactor I guess?), so it doesn't really matter how cheap the reactor is if it uses that fuel.
