The Sendai nuclear plant in Kyushu may have cleared a major hurdle toward its restart on Wednesday, but anti-nuclear groups warn it's far from ready to go online.

Improved evacuation plans and a better understanding of the possible impact of a volcanic eruptions in southern Kyushu are among the unresolved issues for Kyushu Electric Power Co., the operator of the plant in Kagoshima Prefecture, critics say.

"A major flaw (with the evacuation plans) is that there is no specific plan to evacuate people who are deeply dependent on others, such as the elderly, those in the hospital or at care facilities, and where to take them," the Citizens' Commission on Nuclear Energy, a Tokyo-based anti-nuclear group, said in a statement released after the Nuclear Regulation Authority effectively gave the green light for restarting the Sendai plant.