One significant result of the TMI-2 nuclear accident was the formation of a hydrogen gas bubble in the reactor pressure vessel that housed the damaged, partially melted fuel core. Any introduction of oxygen into this gas bubble system would set the stage for a potential explosion that could easily compound an already dire situation. One of the questions regarding a potential source of oxygen produced by thermochemical water splitting was how could an observer determine whether or not there was boiling in the core. The following behind the scenes account provides one answer that proved effective. The first link below provides the detail on the bubble scare in Volume 1, section 16.
