FYI, I've passed my laptop through, in standby, with no apparent change in operation when later opened. (That would be a target size of, less than 1GB I think, of active, in use, RAM. Data that I would expect might cause a crash if it gets corrupted.) I would expect DRAM to be more vulnerable to EEPROM cells, or some Flash. (I wouldn't think CPLDs are using the latest, highest density Flash processes, no?)
AFAIK, erasing EEPROMs is possible with x-rays, but only with extreme levels, levels that cause rapid and permanent damage to the chip. Whereas electronic erase cycles might be 10^5, or UV cycles might be 10^3, x-ray cycles are like... 10^1 if that. Or something.
Also AFAIK, most programmable devices are rated for assembly inspection x-raying, which are probably around the same level?? I can't remember actually reading such a rating actually, but it must exist? There are plenty of no-lead packaged devices out there, that would need to be x-rayed, that can be supplied pre-programmed. Which means they need to retain their programming through soldering cycles, too.
Tim