Beside the heat problem, the YEC concept of accelerated nuclear decay does not seem to fit coherently into their story. I have struggled to explain this, so here’s another attempt. Corrections are welcome.
It seems to me that biblical miracles take a couple of forms. Sometimes they are direct, like turning water into wine or raising Jesus. In direct miracles, either there is no scientifically describable process involved or it’s irrelevant; God desired an outcome and caused it somehow. The fact that it’s inexplicable is intentional; it provokes amazement. Other times, biblical miracles are indirect, like sending a wind to carry locusts to destroy crops. One could observe how the wind moved the locusts and the locusts ate. But again, how God caused the wind is unknown and irrelevant; He had a reason for wanting it.
Accelerated decay seems to be neither. A direct miracle would be God directly changing young-looking rocks to look old. It’s hard to imagine any point in that but deception, so that’s out. An indirect miracle would be God miraculously accelerating decay so that (eg) its heat and radiation would accomplish something else, like the wind blowing the locusts. But accelerated decay would be way too powerful for any conceivable purpose, which is why YECs imagine miraculous heat removal; it would be like sending a hurricane to divert a falling snowflake but then ensuring it does nothing else. If almost all the heat and radiation were miraculously removed, it’s basically a direct miracle again, since the main effect is to make rocks look old.
Perhaps YECs think of accelerated decay more like a side effect of God turning up the “chaos” dial as part of the flood (although with God, all side effects would be foreseen). But that sounds like God making mistakes - “whoops, I’d better remove this heat so I don’t vaporize the planet, and it’s too bad that these rocks will look confusingly old.” God is no bumbler.
Also, this makes no sense because of how decay works; it’s not one process within a rock but many parallel chains of processes. Here I’m getting out of my depth, but maybe others can check me. The nuclear decay of one atom often involves a chain of decays from isotope A to B, B to C, and so on. In the same rock unit, other isotopes may be decaying from J to K, K to L, and so on. And most atoms are not decaying at all, decay being a “random” (unpredictable for humans, not for God) process.
Furthermore, the decays in a chain vary. Looking at the table of nuclides, it appears to me that some are unstable because they have too many neutrons for their protons and others because they have too few. This, I gather, has something to do with the delicate balance of different forces in the nucleus which depend on its size and composition. Different imbalances lead to different types of decay, like little towers of blocks toppling left or right. You can’t speed them all up by tipping the board to the left; that would speed up some and slow down others. So there couldn’t be some single change in the strength of one force which would cause accelerated decay.
So if you wanted to accelerate all decay in a rock, you’d have to micromanage each atom, now tilting the nuclear forces this way to speed up the A to B decay, now tilting them the other way to speed up the B to C decay, and so on. The number of individual, careful changes you’d need to make just for one rock would be astronomical. Accelerating nuclear decay by changing physical constants would be less like tilting a table and more like playing a symphony. You’d have to manage each atom’s decay series carefully for the various decays happening by different mechanisms and at different rates to end up with the same amount of apparently elapsed time. Multiply that by many rocks worldwide and it’s mind boggling.
Even then, it wouldn’t explain increasing apparent ages as you go down the geological strata, or why we’d see large apparent ages in stalactites and coral that formed (by YEC reckoning) after the flood, or in meteorites and Mars rocks that would seem to have no connection to it.
So to summarize, accelerated nuclear decay doesn’t make sense as a miraculous end in itself, or as a miraculous cause for some other effect, or as a side effect of some other miraculous activity. It doesn’t seem to make sense at all, even in a YEC framework.
If you find a pocket watch, you assume it had a designer. If you find a meteorite where multiple decay series, each measured independently by multiple labs, show the same (within error bars) large apparent age, and if you find many such examples of consistently dated rocks and meteorites, it’s not plausible that it’s a coincidence or side effect. Either the rocks are truly old, or the miracles involved in making them look that way were extremely elaborate - more befitting Loki than Yahweh. The challenge for YEC is to suggest a third option that explains the facts.
Did I get the science right? I’d love feedback from anyone who has actually studied nuclear decay formally.