Tokyo ( CNN ) -- Radiation readings near tanks holding toxic water at Japan 's crippled nuclear power plant have jumped to a new high , the plant operator said Wednesday . Tokyo Electric Power Company , which has been struggling to deal with a series of leaks at the Fukushima Daiichi nuclear plant , said it detected a radiation level of 2,200 millisieverts near the tanks on Tuesday . That 's up from a previous high of 1,800 millisieverts on Saturday . Those levels , detected around the same tank , are strong enough to kill an unprotected person within hours . But TEPCO said the type of radiation is easy to shield against . How did we get to this point ? The announcement of the increased reading came a day after the Japanese government officially stepped into the effort to deal with the contaminated water crisis at the Fukushima plant , which was severely damaged by the massive earthquake and tsunami that struck northeast Japan in March 2011 . The government said Tuesday that it would spend the equivalent of $ 470 million on measures that included an ambitious plan to freeze the ground surrounding the plant 's stricken reactors to prevent the contamination of groundwater at the site . TEPCO has accumulated a vast volume of tainted water in roughly 1,000 huge storage tanks at the site , some of them hastily assembled in the aftermath of the tsunami . More leaks feared at Fukushima . And the amount of radioactive water at the plant keeps growing day by day , as groundwater seeps in and the company pumps liquid around the damaged reactors to keep them cool . Last month , TEPCO said one of the tanks at the site had leaked 300 tons of toxic water , prompting Japan 's nuclear regulator to declare the situation a Level 3 serious incident , its gravest assessment since the reactor meltdowns at the plant in 2011 . TEPCO looks for outside help to stabilize crippled Fukushima nuclear plant . The nuclear watchdog , the Nuclear Regulation Authority , said this week that the recent high radiation readings have raised suspicions of more leaks from other water containers . TEPCO said Wednesday that it had n't found any leaks from this tank and that the cause of the high radiation reading was under investigation . Japan fed up with 'whack-a-mole ' approach to Fukushima .
TEPCO says it measured radiation of 2,200 millisieverts at the plant . The reading came from near a tank holding contaminated water . The previous highest reading around that tank was 1,800 millisieverts on Saturday . Those levels are strong enough to kill an unprotected person within hours .