Toyama and Iwate prefectures signed a disaster debris memorandum Monday stating that Toyama will conditionally help Iwate store and incinerate the mountains of waste generated by the March 2011 earthquake and tsunami.

The conditions set out by Gov. Takakazu Ishii and Iwate Gov. Takuya Tasso include prior consent from residents near disposal facilities in Toyama and radiation levels for cesium below the central government's limit of 100 becquerels per kilogram of debris.

Before signing the memorandum, Gov. Takakazu Ishii visited a debris sorting facility in Yamada, Iwate Prefecture, where he said radiation levels were lower than expected.

"It has become easier to secure consent from Toyama residents on safety," Ishii said.

Debris disposal has been slow in Iwate, Miyagi and Fukushima, the prefectures hit hardest by the March 2011 disasters that also triggered multiple core meltdowns at the Fukushima No. 1 power complex.

But unlike Fukushima, where efforts are being made to keep debris-disposal within the prefecture, other prefectures are reluctant to store and incinerate debris from Iwate and Miyagi due to the unknown effects of radiation exposure.