TOKYO - Highly radioactive iodine seeping from Japan’s damaged nuclear complex may be making its way into seawater farther north of the plant than previously thought, officials said Monday, adding to radiation concerns as the crisis stretches into a third week.

Mounting problems, including badly miscalculated radiation figures and no place to store dangerously contaminated water, have stymied emergency workers struggling to cool down the overheating plant and avert a disaster with global implications.

The coastal Fukushima Dai-ichi power plant, located 140 miles (220 kilometers) northeast of Tokyo, has been leaking radiation since a magnitude-9.0 quake on March 11 triggered a tsunami that engulfed the complex. The wave knocked out power to the system that cools the dangerously hot nuclear fuel rods.

On Monday, workers resumed the laborious yet urgent task of pumping out the hundreds of tons of radioactive water inside several buildings at the six-unit plant. The water must be removed and safely stored before work can continue to power up the plant’s cooling system, nuclear safety officials said.

The contaminated water, discovered last Thursday, has been emitting radiation that measured more than 1,000 millisieverts per hour in a recent reading at Unit 2 - some 100,000 times normal amounts, plant operator […]