Tokyo ( CNN ) -- Japan has slapped new restrictions on green tea and plums from areas around the Fukushima Daiichi nuclear power plant because of lingering radioactive contamination from the ongoing disaster there . The latest government bans were prompted by the discovery of radioactive cesium-137 and -134 at concentrations higher than Japanese standards allow , Chief Cabinet Secretary Yukio Edano told reporters Thursday . Both are nuclear waste products : cesium-137 has a half-life of 30 years , while cesium-134 has a two-year half-life . The government has now forbidden the shipment of both fresh and dried green tea -- normally touted for its health benefits -- from Ibaraki Prefecture , southwest of the plant ; from six towns in Chiba Prefecture and six towns in Kanagawa Prefecture , near Tokyo ; and two in Fukushima Prefecture , where the crippled plant is located . In addition , Edano said , the government has banned the shipment of plums from three towns in Fukushima . The moves come nearly three months into the crisis at Fukushima Daiichi , the worst nuclear accident since the 1986 Chernobyl disaster . One of three operating reactors at the plant melted down after the March 11 earthquake and tsunami , and the other two suffered extensive damage to their radioactive cores . Though no deaths have been attributed to the accident , the resulting contamination has forced authorities to evacuate more than 100,000 people from towns surrounding the plant . In addition , restrictions on various agricultural and fisheries products have devastated Japanese farmers and fishermen since the disaster began , though some of those bans have been lifted in recent weeks . The plant 's owner , the Tokyo Electric Power Co. , has laid out a timetable for restoring normal cooling systems and fully shutting down the reactors by January . But Prime Minister Naoto Kan cautioned that people may not be allowed to return home immediately , `` even if these prospects are realized . '' `` We might have to continue monitoring , and we need to maybe decontaminate , '' said Kan , whose government survived a no-confidence vote Thursday spurred by complaints about his handling of the twin crises . `` And for that , there may be some more time needed . '' The disaster has spurred Japan to rethink its commitment to nuclear energy and tighten safety standards for existing plants . A preliminary report from the International Atomic Energy Agency concluded this week that Japan underestimated the risks its nuclear installations faced from tsunamis , like the one that swamped the Fukushima Daiichi plant and knocked out its cooling systems . But the U.N. nuclear watchdog agency declared the country 's response to the disaster `` exemplary , '' praising Tokyo Electric 's operators for their `` brave and sometimes novel '' efforts to contain the crisis . CNN 's Junko Ogura contributed to this report .
Radioactive cesium levels prompt new action by Japan . Green tea , plums are among the latest bans . Tokyo Electric hopes to wind down the crisis by January .