Two workers at Japan's crippled Fukushima nuclear power plant have been exposed to radiation levels more than twice the government limits.

The announcement by the government and the plant operator Friday is the first report that workers may have been exposed to dangerous limits of radiation. However, Tokyo Electric Power says more workers may have been exposed to high levels of radiation and are being tested.

The two workers in this case are in good health now, Tepco says, but will require monitoring in the future. Their exposure equaled more than 1,000 abdominal x-rays.

The men had been working with the Fukushima plant's number 3 and 4 reactors after the plant was hit by a massive earthquake and tsunami on March 11th. Since then, the company has struggled to bring the reactors under control, and it says there has been a partial nuclear fuel meltdown in some of the reactors.

Excessive radiation exposure can lead to cancer and other long-term health problems. Massive doses of radiation can be quickly deadly, but no one has died in the Fukushima disaster, one of the worst in the history of nuclear power.