TOKYO » Radiation in seawater at the shoreline off Japan’s tsunami-ravaged nuclear power plant has measured several million times the legal limit over the past few days, though officials contended Tuesday that the contamination still does not pose an immediate danger.

Radiation has been pouring in to the Pacific from the Fukushima Dai-ichi plant since a 9.0-magnitude earthquake spawned a massive tsunami that inundated the complex. Over the weekend, workers there discovered a crack where highly contaminated water was spilling directly into the ocean.

Experts have said that radiation dissipates quickly in the vast Pacific, but they have also said that it’s unclear what the long-term effects of large amounts of contamination will be.

Plant operator Tokyo Electric Power Co. said Tuesday that samples taken from seawater near one of the reactors contained 7.5 million times the legal limit for radioactive iodine on April 2. Two days later, that figure dropped to 5 million.

TEPCO said in a statement that even the large amounts would have “no immediate impact” on the environment but added that it is working to stop the leak as soon as possible.

The readings were taken closer to the plant than before — apparently because new measuring points were added after the crack was discovered — and did not necessarily reflect a worsening of the contamination. Other measurements several hundred yards (meters) farther away from the plant have declined to levels about 1,000 times the legal limit.

Radiation measurements from Tokyo Electric Power Co. were called into question last week, and the nuclear safety agency ordered the utility to reanalyze its samples. As a result, some figures were held back and several days worth of measurements were released Tuesday.

Radioactivity is pouring into the ocean in part because workers at the plant have been forced to use a makeshift method of bringing down temperatures and pressure by pumping water into the reactors and allowing it to gush out wherever it can. It is a messy process, but it is preventing a full meltdown of the fuel rods that would release even more radioactivity into the environment.

It means means water is pooling throughout the plant, and some of it is making its way to the ocean. Workers are now desperately trying to find a place to store it because it is also preventing them from restoring normal cooling systems.

Starting late Monday, they have been pumping more than 3 million gallons of less contaminated water into the sea in order to make room in a storage facility for the more highly radioactive water. That process is expected to take two days.