The operator of Japan's crippled Fukushima nuclear plant on Thursday said another tank holding highly contaminated water is leaking, and that some of the liquid may have reached the Pacific Ocean, the second such breach in less than two months.
Tokyo Electric Power, or Tepco, said the water that leaked contained 200,000 becquerels per litre of beta-emitting radioactive isotopes including strontium 90. The legal limit for strontium 90 is 30 becquerels per litre.
(Read more: 5.3 magnitude earthquake strikes Japan's Fukushima)
Tepco has been relying on hastily built tanks to hold excess cooling water flushed over damaged reactors at the Fukushima Daiichi site, where three units suffered nuclear meltdowns and hydrogen explosions after a March 2011 earthquake and tsunami.