Worn Pipes Shut California Reactors ( the pipes are relatively NEW!)

[Sirveri]

6. via the water chem guys adding H2 to the primary.

secondary has air ejectors which are used as gas scavengers (combined with the steam generator pulling all gasses out of solution should keep O2 levels quite low in that arena). Don't have those running and good luck maintaining a vacuum within tolerance.

But they said radioactive steam, which typically means failure of the primary side with leakage at the tube sheet since the tubes should be 'double tube' or tube within a tube meaning it would have to eat thru both sides. Though once accomplished the higher pressure primary would typically pass into the secondary, so I guess it's possible they screwed up the boiler chem and got sediment hideout which did the same thing.