I have never seen any occurance of Bryce "autosaving", so I doubt it.

I live in a part of the country that experiences many severe thunderstorms a year and often the power goes out and everything stops even just for a seconds long power fluctuation.

I have my computer plugged into a battery backup called a Universal Power Supply that takes the load when the power is interrupted suddenly and everything stays working for some certain minute duration(depending on the unit) until the power comes back. The more expensive units have longer minute or perecentage of hour durations and last longer in those blackouts - but unless you have a whole house emergency generator, you will lose your renders that last over the time your UPS will stay working.

At the minimum, depending on your budget, I would suggest to at least get a UPS to help mitigate the problem.

Sorry for the long answer when a "probably not" would have sufficed!