Don't let Oakland scare you. Like any urban city, there are very bad areas, very nice ones, and everything in between. Kaiser Oakland happens to be (as the previous poster wrote) right on the edge of a really cool neighborhood with lots of great restaurants all along Piedmont Ave. I went to nursing school and lived on campus less than a half mile from there.
Honestly, you'll probably be a lot happier with your experience during this assignment if you live in Oakland or Berkeley. You'll save money, getting to work will be wayyyy easier, there's plenty of great restaurants and entertainment in the area (Piedmont Ave, Shattuck, Jack London Square, all super fun areas) and if you want to go in to SF to do something it's easy to do.
For the money, San Francisco's a better place to visit/day-trip than to live.