U.S. nuclear reactors are safer than they were before the Fukushima Daiichi meltdown that occurred three years ago in Japan, but automated data collection systems are still not prepared to operate in extreme conditions, according to a Government Accountability Office report.

The GAO report, which studied 16 countries and was requested by the State Department, recommended that the Nuclear Regulatory Commission quickly decide how and whether to upgrade data systems to withstand severe situations. Those systems are responsible for communicating critical power plant data to regulators.