The thousands of radiation-monitoring posts installed in Fukushima Prefecture after the 2011 nuclear crisis have malfunctioned nearly 4,000 times, sources said Sunday as the Nuclear Regulation Authority prepares to remove them after spending ¥500 million a year on repair costs.

"It's all about the budget in the end. They can't reuse the devices and there seem to be no concrete plans," said Terumi Kataoka, a housewife in Aizuwakamatsu who formed a group of mothers to petition the NRA last month to keep the monitors in place. The NRA refused.

Around 3,000 of the monitors were installed in the wake of the triple core meltdown at the Fukushima No. 1 power plant following the March 2011 mega-quake and tsunami. The NRA, which operates the monitoring posts, plans to remove around 80 percent of them by the end of fiscal 2020 on the grounds that radiation levels in some areas have fallen and stabilized.