Post 72 hour Support

If power has not been restored to the site after 72 hours, operators can take action to continue the flow of makeup water and cooling from the containment vessel. The operator will start the ancillary diesel generators on-site and starts the passive containment cooling recirculation pump.

The pump transfers water from the Passive Containment Cooling Ancillary Water Storage Tank (PCCAWST), located on-site, to the PCCWST on top of the shield building from 72 hours to at least 7 days following the start of the station blackout.