The government on Friday kicked off a two-day nuclear evacuation drill — its first since the 2011 Fukushima No. 1 power plant disaster — with the aim of making the exercise more realistic than its usual scripted rehearsals.

The drill is based on a scenario in which an earthquake causes an accident at one of the two reactors at the Sendai power plant in Kagoshima Prefecture, resulting in the release of radioactive substances and orders to evacuate.

The exercise is intended to test the effectiveness of the nation’s new nuclear disaster mitigation guidelines, which expanded the evacuation radius to 30 km from a radiation source instead of 10 km.

The Nuclear Regulation Authority said around 3,300 people will take part, including local, prefectural and national officials, power utilities and residents.

The drill is expected to feel closer to reality because many of the participants will not be given advance details of when and how the scenario will unfold, an NRA official in charge of the issue said.

“In past exercises, participants knew all the scenarios and their statements were prepared — which was more like performing a role in a drama. But we found that this method will not nurture people’s ability to cope with the situation,” he said.

The state, local governments and nuclear power plants will also practice coordinating their responses in the joint exercise, such as by using teleconferencing systems to share information.

Residents within 5 km of the plant will be told to evacuate before radioactive release starts, while some of those farther out, up to a 30-km radius, will flee based on the assumption that radiation levels requiring evacuation have been detected.

In the Fukushima crisis, which involved three core meltdowns after the huge earthquake and tsunami of March 2011, residents within 20 km of the plant and some areas beyond eventually were told to evacuate.

The evacuation process caused great confusion because the government was unprepared and revised the evacuation zones several times while the crisis was unfolding. Many residents fled with only the barest necessities and in some cases even headed to areas with higher radiation levels because the government sat on nuclear fallout projections calculated by SPEEDI, a state-funded computer system designed just for that purpose.

In addition, the central government dragged its feet in advising the distribution and use of iodine pills to residents to help prevent thyroid cancer.

Under the new disaster mitigation guidelines, residents within 5 km of a nuclear power plant will be given a supply of iodine tablets in advance so they can promptly take them.

The tablets have not yet been distributed to people participating in the drill, but residents will be asked to act on the assumption that they have the tablets, according to the NRA.