Japan's nuclear safety agency on Friday said it warned TEPCO for not having enough radiation meters for all workers battling to stabilise its Fukushima nuclear plant after devices were lost in a tsunami.

Tokyo Electric Power Co. lost most of its dosimeters for workers at the Fukushima Daiichi plant when the tsunami from a 9.0 magnitude quake tore into the plant, the Nuclear and Industrial Safety Agency said Friday.

To cope with the dosimeter shortage TEPCO had emergency crews working in teams to try to restore stricken plant systems, giving one meter per group to monitor radiation in their work areas, another agency official said.

The embattled company had since sourced enough dosimeters for all workers, the agency said, amid reports this week of tough working conditions for those at the plant. TEPCO could not immediately be reached for comment.

The agency declined to clarify when it had been aware of the shortage of radiation meters.

"The agency warned TEPCO yesterday (Thursday) to do the utmost to manage workers' exposure levels," said agency spokesman Hidehiko Nishiyama.

The number of dosimeters available had declined from an initial 5,000 to 320 after the tsunami damaged devices, Kyodo news reported.

By Thursday TEPCO had sourced around 420 detectors and was able to give one to each worker, said Nishiyama.

"The company also told us that it will not allow any workers to go in without a detector," said Nishiyama.

Some 500 workers with TEPCO, its subsidiaries as well as an army of firefighters and soldiers are working at the plant. Dangerous levels of radiation have hindered progress, and some workers have been hospitalised.

The government last week ordered TEPCO to "thoroughly enforce workforce management" after two workers were hospitalised after wading through a highly radioactive puddle of water without appropriate safety gear.

The March 11 wave crippled the Fukushima Daiichi cooling systems, triggering explosions and fires as reactors overheated and entered partial meltdowns, releasing radiation into the environment.

According to the Nuclear and Industrial Safety Agency, a total of 21 workers have been exposed to radiation exceeding 100 millisieverts so far during the ongoing crisis at the plant, the lowest level at which an increase in cancer risk is evident.

Workers are usually permitted to be exposed to up to 100 millisieverts in an emergency situation. The limit, however, has been raised to 250 millisieverts specifically for the work at the plant.

earlier related report
TEPCO reviews radiation data
Tokyo (AFP) April 1, 2011 - Tokyo Electric Power Co, operator of a stricken Japanese nuclear plant, is reviewing previously disclosed radiation data due to a possible calculation error, Japan's nuclear safety agency said Friday.

The beleaguered company, already under fire for earlier data errors, has monitored levels of radioactivity in the air, soil, and pools of water at the plant and nearby seawater, and has disclosed a barrage of radiation data.

TEPCO said it had found problems with its computer analysis of the radioactive material tellurium, after the Nuclear and Industrial Safety Agency said TEPCO's analysis of groundwater radiation at the site could be erroneous.

The agency said TEPCO was reviewing reported levels of such isotopes as tellurium 129 and molybdenum 99.

"The agency ordered the company to review the data because we found that there is an error in the calculation programmes of each isotope," said a spokesman for Japan's Nuclear and Industrial Safety Agency.

"We believe this mistake in its data report may damage the trust in TEPCO and is very regrettable," said Hidehiko Nishiyama, a senior official of the agency, which supervises the operation of the nation's nuclear plants.

The agency had earlier questioned a TEPCO report that radioactive iodine-131 in groundwater below Japan's stricken nuclear plant was 10,000 times higher than the safe level set by the government.

TEPCO said it found no problems in its radioactive iodine and caesium readings, Dow Jones Newswires reported.

The utility drew fire for erroneously reporting last week that radiation in pools of water in the turbine room of a stricken reactor at the plant hit 10 million times the normal level, later correcting it to a still dangerously high level.

Three weeks on from the March 11 earthquake and tsunami, the situation at Fukushima Daiichi remains unresolved after the plant's reactor cooling systems were knocked out, triggering explosions and fires and releasing radiation.

Radiation from the plant northeast of Tokyo has wafted into the air, contaminating farm produce and drinking water, and has seeped into the Pacific Ocean, although officials stress there is no imminent health threat.

The government slammed the erroneous TEPCO data as "absolutely unacceptable", and the company pledged to be more careful.

As the nuclear crisis risks turning into a quagmire of erratic and opaque data, the government Friday sought expert help in relaying data to the public.

Chief Cabinet Secretary Yukio Edano met six nuclear experts and asked for help "so as to appropriately convey information, such as the radiation impacts on human health, to citizens", Jiji Press said quoting the official.

earlier related report
China detects 10 cases of radiation contamination
Beijing (AFP) April 2, 2011 - China has detected 10 cases of radioactive contamination among passengers, aircraft, ships and containers arriving from Japan since March 16, quarantine authorities said on Saturday.

On Wednesday, radiation exceeding permitted levels was detected on two ships from the Japanese port of Chiba, near Tokyo, in the ports of Nantong and Zhangjiagang, Li Yuanping, spokesman of the General Administration of Quality Supervision, Inspection and Quarantine, said on its website.

Similar radiation was measured on four vessels that arrived from Japan at various ports over the next two days.

Higher than normal radiation was also detected Friday on a flight from Tokyo to the eastern city of Hangzhou, the administration's website said.

Abnormally high radioactivity was first detected on a ship that arrived from Japan at the southeast port of Xiamen on March 22.

Two Japanese travellers were briefly hospitalised the next day with elevated radiation levels after arriving in eastern China on a commercial airliner from Tokyo. Their clothing and luggage was destroyed.

The ministry of environmental protection reported late Friday that very small quantities of iodine-131 and caesium-137 and -134 had been detected in the atmosphere of every Chinese province except Tibet.

The amounts were too small to represent a health hazard, the ministry said.

China last week banned the import of fruit, vegetables, dairy products and seafood from regions close to the site of the stricken Fukushima nuclear power plant, which has continued to release radioactivity into the environment since it was crippled in the March 11 earthquake and tsunami in northeast Japan.

earlier related report
Moscow 'detects radioactive particles' from Japan
Moscow (AFP) April 1, 2011 - Radioactivity from Japan's damaged nuclear reactor has been detected in the atmosphere around the Russian capital Moscow, officials from the municipal facility treating nuclear waste said Friday.

Radon, a company set up in Moscow to monitor radioactivity and dispose of radioactive waste in central Russia, has been detecting traces of iodine and strontium isotopes since last week, deputy director Oleg Polsky said.

The minuscule amounts were possible to detect only via the company's powerful filtering systems and don't pose any health risks, he said.

"Starting March 23rd, we began registering activity, whose make-up corresponds to that which comes from accident situations on nuclear reactors," the company's Sergei Gordeyev said.

Detected isotopes include radioactive Iodine-131 in aerosol and gas form, cesium-134 and cesium-137, and tellurium-132, he said at a press conference in Moscow.

"The isotopes confirm that it's a process connected with the accident," said Polsky, "but these traces are not dangerous for people."

The earthquake and tsunami that ravaged Japan's northeast coast and left about 28,000 dead or missing also knocked out reactor cooling systems at the Fukushima plant, which has leaked radiation into the air and sea.

Jitters continued throughout Asia this week that radiation had drifted over their territories, even though they emphasised the levels were so small there was no health risk.

Traces of radioactive iodine believed to be from Japan's damaged nuclear plant have even been detected as far afield as Britain, officials said Tuesday.