Just popped in to share a howler alarm sound. I haven't delved into the actual nuclear stuff as of yet, but I have an extensive sorting system which was getting overflows in certain cases. So I rigged an alarm for when my overflow chests contain items. The sound is a mildly high pitched UK female computerish voice saying "Item overflow detected." It's not as loud as the default howler sounds and wasn't intended to be as the occasion is not meltdown-level critical.
Also, not sure if it matters but it was made for and tested on IC2NC 1.4.5 (MC 1.4.7).