The central and local governments will hold a nuclear-disaster drill on Oct. 28 simulating an "off-site risk" at a nuclear plant on the Sea of Japan coast, according to local antidisaster officials.
The mock accident at the plant in Shimane Prefecture will simulate an accident categorized by the International Atomic Energy Agency as an off-site risk, meaning that not only people at the site but those nearby are in danger of being exposed to dangerous levels of radiation.
The severity of the mock meltdown will rate a level 5 on the agency's scale, which is as serious as the 1979 accident on Three Mile Island.
It will assume that 50 millisieverts of radiation have contaminated the area within 2 km of the plant and 10 millisieverts contaminated the area within 6 km. A Japanese law sets the maximum annual exposure of radiation for people not working in designated areas as 1 millisievert.
About 11,000 residents of the town of Kashima, where the plant is located, and the city of Matsue will be ordered to stay home.
The plant is operated by Hiroshima-based Chugoku Electric Power Co.
About 110 other people living near the plant will be evacuated by Self Defense-Forces vehicles to a shelter.
The drill will be mainly led by a special task force headed by Prime Minister Yoshiro Mori in Tokyo, the officials said.
The drill centering around the No. 2 reactor will be the first carried out in line with an antidisaster law created after Japan's worst nuclear accident, which occurred in Tokai, Ibaraki Prefecture, on Sept. 30, 1999.