Chronic electrical surges at the massive new data-storage facility central to the National Security Agency's spying operation have destroyed hundreds of thousands of dollars worth of machinery and delayed the center's opening for a year, according to project documents and current and former officials.

There have been 10 meltdowns in the past 13 months that have prevented the NSA from using computers at its new Utah data-storage center, slated to be the spy agency's largest, according to project documents reviewed by The Wall...