A hot spot refers to an area that has a high level of radiation following rain or as a result of landscape or wind conditions that affect the direction in which radioactive materials travel after being released into the air.
Normally, radiation spreads concentrically but under such conditions, radioactive materials spread randomly to various spots.
Top government spokesman Yukio Edano said at a news conference there are certain spots, other than the government-designated evacuation areas, where radiation levels are high depending on atmospheric and other conditions, and the government will boost monitoring at these locations.
‘‘Based on the outcome of (radiation) monitoring, we will consider taking appropriate action,’’ the chief Cabinet secretary told a news conference, hinting at the possible evacuation of these areas.
Separately, Deputy Chief Cabinet Secretary Tetsuro Fukuyama told an opposition lawmaker that some parts of Minamisoma city in Fukushima have registered high levels of radiation, and the government will consult with the mayor and other officials on whether or not to evacuate the residents there.
Following the devastating March 11 earthquake and tsunami that triggered a nuclear emergency, the government ordered the evacuation of people living within 30 kilometers of the Fukushima Daiichi plant, which lost its key cooling functions and continues to spew radiation.
The government has since prohibited people from entering areas within a 20-kilometer radius of the crippled Fukushima plant and added some towns outside the limit to the list of areas covered by its evacuation directive due to concerns over high levels of radiation exposure.