Japanese engineers measured on Monday radiation levels at the crippled Fukushima Daiichi nuclear power plant, NHK television reported.
A group of nine specialists from the plant's operator, Tokyo Electric Power Co. (TEPCO), entered the No. 1 reactor building early in the morning and spent 30 minutes there.
The results have not been disclosed yet.
Japanese officials earlier reported that radiation levels had dropped inside the building after ventilators were installed last week to filter out radioactive substances.
As soon as radiation drops to permissible levels, specialists will attempt to restart the reactor's cooling system, knocked out by a powerful earthquake and tsunami on March 11.
TEPCO expects radioactivity levels at the plant to stabilize within six to nine months. The company also says radioactivity levels in the air around the plant will drop significantly within three months.
The twin natural disaster in northeast Japan in March left more than 25,000 people dead or missing. Thousands more were forced to evacuate their homes in the ensuing nuclear crisis at Fukushima.
MOSCOW, May 9 (RIA Novosti)
