The Nuclear Regulation Authority on Wednesday revised a key guideline that would boost the country's medical preparedness in the event of an atomic disaster, reflecting lessons learned from the March 2011 triple meltdowns at the Fukushima No. 1 complex.

The watchdog is aiming to create a nationwide medical service network over roughly the next three years by asking local municipalities that host nuclear plants to designate one or more hospitals as institutions that can provide emergency treatment for radiation exposure.

The disaster at Tokyo Electric Power Co.'s Fukushima No. 1 nuclear power plant saw enormous amounts of radioactive materials belched into the environment, and exposed the vulnerability of hospitals and medical networks in the event of an atomic emergency. Because hospitals were not prepared to deal with a situation where radioactive substances are diffused over a wide area, many evacuees were not given proper treatment.

The regulator designated a total of five university hospitals and research institutions as facilities for treating large numbers of people exposed to high-level radiation who could not be treated locally. These sites include Fukushima Medical University and Hiroshima University.

Under the revised guideline, the watchdog is also calling for strengthening medical staffers' education on radiation treatment, while organizing teams — comprised of doctors, nurses and nuclear experts — that will be dispatched to support local hospitals in the event of a nuclear emergency.

On Aug. 11, a reactor at the Sendai nuclear power plant in Kagoshima Prefecture was the nation's first to be rebooted under the post-Fukushima, upgraded safety regulations.

The government is seeking to reactivate the remaining idled reactors that have cleared the beefed-up regulations, though lingering safety concerns and a majority of the public opposed to nuclear power remain obstacles to that goal.