Gee. Every time I have been in a power plant I thought the lights in the conference room were fed directly from the generator.<quoted text>
"DR" = Dominican Republic?
Doesn't really work the way you're thinking, generated electricity goes onto the grid for distribution.
No this wasn't planned for but was accounted for in design. Problem was the earthquake was beyond the design basis by a factor of around 10 (that's 10 times more powerful than the plant was designed to withstand) and the tsunami was 3-4 meters above design basis. You can't base designs on theoretical worst-case-in-history events.
Every engineered facility, power plant or otherwise, has a design basis. Sometimes that basis may be exceeded. As we learned (or have failed to learn) from Katrina.