TOKYO, May 9, 2011 (AFP) - The operator of Japan's stricken nuclear power plant may need to use lead sheets and metal tunnels to protect workers seeking to stabilise its reactors, the nuclear safety agency said Monday.
Before dawn Monday, Tokyo Electric Power Co (TEPCO) sent a team to measure radiation inside the building housing reactor one and detected levels between 10 and 700 millisieverts per hour in different parts of the structure.
Japanese nuclear workers are only allowed to be exposed to cumulative radiation of 250 millisieverts -- meaning they could only stay in reactor one's most contaminated areas for about 20 minutes before hitting their limit.
"An area with a double-digit millisievert level, let alone three-digit figures, is quite tough as a working environment," said Hidehiko Nishiyama, a spokesman for the Nuclear and Industrial Safety Agency, Kyodo News reported.
"So we have to do the work by using some shielding."
TEPCO, which has installed air ventilation systems in the plant, is hoping to start full-scale work soon to replace the cooling systems that were knocked out by the March 11 tsunami that slammed into the plant.
To protect workers against radiation, TEPCO is considering constructing a metal tunnel for them to walk through, or using lead sheeting, Nishiyama told the press conference.
Seven TEPCO workers and two nuclear safety agency officials went into the reactor building for about half an hour from 4:20 am local time (Sunday 1920 GMT) to take the radiation readings, officials said.
"This is the first step toward actual preparations for arranging working conditions so that we can move to construction of a cooling system," said TEPCO spokesman Hajime Motojuku.
