Maybe it was the best trade-off at the time. They had to do something to reduce that heat load or risk challenging the pressure/temperature limits of the vessel and/or containment. If the normal supply of emergency coolant was unavailable, they had to go with something, and that meant sea water. I am curious to see if there wasn't damage to the neutron-absorbing baffles of the storage pools. If there was that could account for some of the neutron flux readings (not accidental criticality so much as photoneutron production).
I am curious to see if there wasn't damage to the neutron-absorbing baffles of the storage pools.
Saw some recent video of the damage to the roof area (forget which reactor) this morning. Doesn't look good for the storage pool.