Japan's New Threat: Radioactive Groundwater

The Guardian reports:

Workers at the Fukushima Daiichi nuclear power plant face new threats to their health after radiation exceeding safety levels was found to have seeped into groundwater near the facility.

The plant's operator, Tokyo Electric Power (Tepco), was the target of further criticism amid reports that some workers at the site had not been provided with personal radiation monitors.

Tepco's handling of the crisis has come under closer scrutiny since three workers were exposed to dangerously high levels of radiation last week. They have all been discharged from hospital after suffering no ill effects.

Japan's nuclear and industrial safety agency, Nisa, ordered the firm to review its latest radiation measurements taken from the air, seawater and groundwater, saying they seemed suspiciously high.

Earlier on Friday Tepco reported that groundwater beneath one of the plant's six reactors contained levels of radioactive iodine 10,000 times higher than government standards.

"We have our suspicions about their isotope analysis," said Hidehiko Nishiyama, a Nisa spokesman. Tepco said that a computer software fault could be responsible for the high readings, but added that the data could turn out to be accurate.

Experts said it was unlikely that the radioactive iodine-131 found nearly 15 metres (50ft) below one of the reactors would find its way into drinking water.