THE operator of Japan's wrecked Fukushima nuclear plant, under fire to put right repeated contamination mishaps, has promised to draft in extra workers and improve equipment as part of plans to make the site safe.

Tokyo Electric Power Company, or Tepco, has been reprimanded twice in as many months by Japan's nuclear regulator for mismanagement in a clean-up operation more than two-and-half years after the Fukushima Daiichi plant was struck by an earthquake and tsunami.

In a statement issued yesterday, after submitting a report to the regulator. Tepco said: "We will increase the workforce at Fukushima Daiichi nuclear power plant and make sure we have an accurate grasp of the situation, follow procedures, introduce proper communications and instructions needed to carry out competent management of the site."

The company said the increase would bring to 200 the number of workers drafted in since September to deal with contaminated water. The clean-up of the disaster, the worst nuclear crisis since Chernobyl in 1986, is expected to take decades.

Tepco has been battling the rising contaminated water at Fukushima, 130 miles north-east of Tokyo, which is leaking into the adjacent Pacific Ocean.

Last week it said radiation levels in nearby seawater had soared to the highest level in two years.