[cyberax]

Yes, it would. Fuel is around 2-4% of the total costs for a regular nuclear power plant, but that's because regular reactors can burn it deeply. This reactor will only burn a couple of percents of the available fuel, so the fuel costs will probably be around 10-20 times higher.

BTW, this tradeoff can be acceptable for some very specific applications. Kilopower ( https://en.wikipedia.org/wiki/Kilopower ) is designed to use passive regulation.