Japanese authorities are preparing to strictly enforce a 20-kilometre restricted zone around the stricken Fukushima Daiichi nuclear complex.

Prime Minister Naoto Kan is set to meet Thursday with local officials and evacuees to discuss plans for enforcement of the restricted zone around the plant, which has been leaking radiation since the March 11 earthquake and tsunami damaged its power and cooling systems.

About 80,000 residents who live within 20 kilometres of the plant were evacuated on March 12, but some have been returning to try to collect their belongings or salvage goods, and police have been unable to stop them.

Authorities want people banned from the area to protect them from radiation and also to prevent thefts.

It is still not clear how access would be controlled.

"There are a number of people who may be entering the area. Under the current regime, we are not in a position to legally enforce — there's no penalty for entering into the area. There is a realization of a need to have a stronger enforcement of the area," Noriyuki Shikata, a government spokesman, said earlier Wednesday.

Tokyo Electric Power Co., the operator of the nuclear plant, also said Wednesday it is distributing applications for compensation to people forced out of the area. The company is offering roughly $12,000 US per person in initial compensation.

Meanwhile, workers trying to get the Fukushima nuclear plant under control are suffering from insomnia, show signs of dehydration and high blood pressure and are at risk of developing depression or heart trouble, a doctor who met with them said Wednesday.

"The conditions at the plant remain harsh," epidemiologist Takeshi Tanigawa told The Associated Press. "I am afraid that if this continues we will see a growing risk of health problems."

With files from The Associated Press