As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ORD INFLIGHT T2337/10MAY - AFT CENTER BOOST PUMP CIRCUIT BREAKER POPPED. CAPTAIN UNABLE TO GET FUEL FROM CENTER TANK. RETURNED TO ORD DUE TO PASSENGER CUSTOMER SERVICE AND MAINTENANCE AVAILABILITY. LANDED WITHOUT INCIDENT. REPLACED AFT CENTER FUEL BOOST PUMP. SYSTEM GROUND CHECKED NORMAL OPERATION.