I was an aging, waste-certified operator stationed at AY tank farm for years. The problem with 102-AY started when they quit running the ALCs (air lift circulators). There are 22 of them in the tank used to help control the heat of the waste and to keep corrosive material from settling in one area.
Then they left the annulus riser caps unbolted for years, often being knocked off by passing workers, letting in rain and snow. I would go out at the end of my shift when the weather was bad to put the caps back on. When there was heavy rain, the south side annulus risers were under water because of flooding, and at times you could hear water being sucked into the annulus through holes in the gaskets.
Add to this, they decided to run the annulus exhauster with a greater negative pressure than the tank. This means if the tank was to leak it would be sucked out of the tank and into the annulus. This was against procedure at the time.
There were also long periods when the 102-AY annulus exhauster was not running, letting any moisture that was there to set instead of being dried out by the air circulation.
COREY MCCORD, Pasco