Why do PWR reactors use boric acid, as opposed to some random salt of boron? Apparently boron salts are often well soluble, from the nuclear POV we only care about boron being present, and I'd expect salts to cause fewer chemical problems due to their closer-to-neutral pH. In fact some random papers (https://inis.iaea.org/collection/NCLCollectionStore/_Public/28/034/28034575.pdf) describe tradeoffs involved in maintaining pH as boric acid concentration changes.

There clearly must be some reason why boric acid is preferred over any simple boron salt. What is it?

#nuclear