Japan restores power to nuclear reactors

Two units at Japan's stricken nuclear plant safely cooled down today, though pressure unexpectedly rose in a third unit's reactor as scientists continued to wage a battle to get a handle on the crisis.

The pressure increase meant plant operators may need to deliberately release radioactive steam, prolonging a nuclear crisis that has consumed government attention even as it responded to the catastrophic earthquake and tsunami that savaged northeast Japan on March 11.

As the official death toll rose to 8,450, with more than 12,900 reported missing, there was news of a rare rescue amid the despair.

A teenage boy's cries for help led police to rescue him and his 80-year-old grandmother from their wrecked house nine days after earthquake struck.

Beyond the disaster area, uncertainty grew over the safety of food and water. The government halted shipments of spinach from one area and raw milk from another near the nuclear plant after tests found iodine exceeded safety limits.

But the contamination spread to spinach in three other prefectures and to more vegetables - canola and chrysanthemum greens. Tokyo's tap water, where iodine was found on Friday, now has cesium. Rain and dust are tainted too.

In all cases, the government said the radiation levels were too small to pose an immediate risk to health.

All six of the Fukushima Dai-ichi nuclear complex's reactor units experienced trouble today after the disasters knocked out cooling systems.

In a small advance, the plant's operator declared Units 5 and 6 - the least troublesome - under control after their nuclear fuel storage pools cooled to safe levels. Progress was made to reconnect two other units to the electric grid and in pumping seawater to cool another reactor and replenish it and a sixth reactor's storage pools.

But the buildup in pressure inside the vessel holding Unit 3's reactor presented some danger, forcing officials to consider venting. The tactic produced explosions of radioactive gas during the early days of the crisis.

"Even if certain things go smoothly there would be twists and turns," said Chief Cabinet Secretary Yukio Edano. "At the moment, we are not so optimistic that there will be a breakthrough."

Nuclear safety officials said one of the options could release a cloud dense with iodine as well as the radioactive elements krypton and xenon.

The plant's operator, Tokyo Electric Power Co., temporarily suspended the plans today after it said the pressure inside the reactor stopped climbing, though staying at a high level.

"It has stabilised," said Tokyo Electric manager Hikaru Kuroda.

Mr Kuroda, who said temperatures inside the reactor reached 572F (300C), said the option to release the highly radioactive gas inside is still under consideration if pressure rises.

Growing concerns about radiation have added to the overwhelming chain of disasters Japan has struggled with since the 9.0-magnitude quake also spawned the devastatine tsunami.

Fuel, food and water remain scarce. The government in recent days acknowledged being caught ill-prepared by the enormity of the disaster recognised as the worst since the Second World war.

Japan government officials today advised villagers in Fukushima not to drink tap water because of radioactive iodine.