Fears another nuclear reactor in Fukushima threatened to go out of control on Sunday morning as Japanese engineers worked to head off a meltdown in the wake of the massive 8.9 earthquake.
The cooling system had stopped working in a sixth reactor, according to latest reports.California is closely monitoring efforts to contain leaks from a quake-damaged Japanese nuclear plant, a spokesman said, as experts said radiation could be blown out across the Pacific.
While officials downplayed any immediate danger, the US Nuclear Regulatory Commission deployed two experts to Fukushima plant in Japan, which was rocked by a large explosion earlier in the day in the aftermath of Japan's strongest-ever earthquake.
In the particularly hard-hit reactor 1 of the Fukushima nuclear plant complex, technicians had begun to flood the system with sea water and boron to head off a meltdown.
In Washington, an official from Japan's Nuclear and Industrial Safety Agency (NISA) told r that a meltdown may be under way, which would be a catastrophic failure of one reactor.
There was no public confirmation of the statement.
Thousands of people were evacuated on Saturday following an explosion and leak from the Fukushima Daiichi plant, 240 km (150 miles) north of Tokyo.
It was believed the first explosion had been contained and disaster avoided.
But on Sunday the plant operator, Tokyo Electric Power (TEPCO) said radiation levels around the Fukushima Daiichi plant had risen above the safety limit and said the cooling system in the number three reactor had failed.
It was preparing to vent steam to relieve pressure in the reactor and the government had warned of a rise in radiation during the procedure.
Fears of a nuclear fallout were first raised when a massive explosion rocked the Fukushima Daiichi atomic power plant following damage to the number one reactor in Friday's earthquake.
A pall of grey-white smoke rose over the plant, operated by Tokyo Electric Power, and it was reported that four workers had been injured.
Government officials revealed plans to distribute iodine tablets – a treatment for radiation poisoning – to locals while a 20km exclusion zone was set up round the plant.
Residents outside the zone were urged to stay inside, close doors and windows and turn off air conditioning. Scientists had detected eight times the normal radiation levels outside the facility and 1,000 times normal levels inside the affected unit's control room.
Japan's prime minister, Naoto Kan, declared a state of emergency at the crippled unit and at its sister plant, the Fukushima Daini, as engineers tried frantically to determine whether the reactor had gone into meltdown.
Japan's nuclear safety agency said the number of people exposed to radiation could reach 160. Officials said radiation levels around the plant had breached saftey levels.
Workers in protective clothing were scanning people arriving at evacuation centres for radioactive exposure.
The chief cabinet secretary Yukio Edano told a news briefing: "They are working on relieving pressure and pumping in water into the number three reactor.
For locals in Fukushima prefecture, still reeling from frequent aftershocks and clearing up after the first disaster, the prospect of another on the way in the form of nuclear meltdown was unwelcome in the extreme.
A loss of coolant inside the first of the plant's six reactors had caused a dangerous build-up of heat. A second, more deadly explosion – one that would have released a vast radioactive plume over the nation – seemed a real prospect until it was announced that, although the outer structure of the 40-year-old reactor building had been blown off by the blast, the actual reactor inside had not been breached.
It was also revealed that the International Atomic Energy Agency was planning an investigation. "We are aware of the media reports and we are urgently seeking further information," an IAEA official told Reuters in Vienna.
In the wake of the impact of Friday's earthquake and tsunami, the Fukushima incident has strained life in Japan to an almost unendurable level, and although catastrophe appears to have been averted the incident has raised serious concerns about Japan's enthusiastic use of nuclear energy.
Reactors generate almost a third of the country's electricity and there are plans, already well advanced, to raise this to 50%. For the nuclear industry, the Fukushima incident could not have come at a worse time. Unravelling what happened and how close the nation came to disaster will preoccupy scientists and engineers for years.
Last night reports suggested that the emergency pumps had failed because they had been swamped by the tsunami triggered by the initial earthquake – an embarrassing failure by those who had planned the reactor's back-up systems.
Whatever the reason, the consequences were dramatic. Without pumps taking away the water that acted as the coolant, the reactors heated up and steam built up inside.
Despite the revelation that caesium had been detected, Japanese officials still claim the reactor's container was not damaged and that radiation levels have started to fall. However, the Japanese nuclear industry has a bad reputation for owning up to accidents and many observers remain cautious about accepting these claims too quickly.
Those opposed to nuclear power will not let the incident be forgotten, as Jan Beranek, head of Greenpeace's international nuclear campaign, made clear. "How many more warnings do we need before we finally grasp that nuclear reactors are inherently hazardous? The nuclear industry always tells us that situation like this cannot happen with modern reactors, yet Japan is currently in the middle of a potentially devastating nuclear crisis," he said.
The cooling system had stopped working in a sixth reactor, according to latest reports.California is closely monitoring efforts to contain leaks from a quake-damaged Japanese nuclear plant, a spokesman said, as experts said radiation could be blown out across the Pacific.
While officials downplayed any immediate danger, the US Nuclear Regulatory Commission deployed two experts to Fukushima plant in Japan, which was rocked by a large explosion earlier in the day in the aftermath of Japan's strongest-ever earthquake.
In the particularly hard-hit reactor 1 of the Fukushima nuclear plant complex, technicians had begun to flood the system with sea water and boron to head off a meltdown.
In Washington, an official from Japan's Nuclear and Industrial Safety Agency (NISA) told r that a meltdown may be under way, which would be a catastrophic failure of one reactor.
There was no public confirmation of the statement.
Thousands of people were evacuated on Saturday following an explosion and leak from the Fukushima Daiichi plant, 240 km (150 miles) north of Tokyo.
It was believed the first explosion had been contained and disaster avoided.
But on Sunday the plant operator, Tokyo Electric Power (TEPCO) said radiation levels around the Fukushima Daiichi plant had risen above the safety limit and said the cooling system in the number three reactor had failed.
It was preparing to vent steam to relieve pressure in the reactor and the government had warned of a rise in radiation during the procedure.
Fears of a nuclear fallout were first raised when a massive explosion rocked the Fukushima Daiichi atomic power plant following damage to the number one reactor in Friday's earthquake.
A pall of grey-white smoke rose over the plant, operated by Tokyo Electric Power, and it was reported that four workers had been injured.
Government officials revealed plans to distribute iodine tablets – a treatment for radiation poisoning – to locals while a 20km exclusion zone was set up round the plant.
Residents outside the zone were urged to stay inside, close doors and windows and turn off air conditioning. Scientists had detected eight times the normal radiation levels outside the facility and 1,000 times normal levels inside the affected unit's control room.
Japan's prime minister, Naoto Kan, declared a state of emergency at the crippled unit and at its sister plant, the Fukushima Daini, as engineers tried frantically to determine whether the reactor had gone into meltdown.
Japan's nuclear safety agency said the number of people exposed to radiation could reach 160. Officials said radiation levels around the plant had breached saftey levels.
Workers in protective clothing were scanning people arriving at evacuation centres for radioactive exposure.
The chief cabinet secretary Yukio Edano told a news briefing: "They are working on relieving pressure and pumping in water into the number three reactor.
For locals in Fukushima prefecture, still reeling from frequent aftershocks and clearing up after the first disaster, the prospect of another on the way in the form of nuclear meltdown was unwelcome in the extreme.
A loss of coolant inside the first of the plant's six reactors had caused a dangerous build-up of heat. A second, more deadly explosion – one that would have released a vast radioactive plume over the nation – seemed a real prospect until it was announced that, although the outer structure of the 40-year-old reactor building had been blown off by the blast, the actual reactor inside had not been breached.
It was also revealed that the International Atomic Energy Agency was planning an investigation. "We are aware of the media reports and we are urgently seeking further information," an IAEA official told Reuters in Vienna.
In the wake of the impact of Friday's earthquake and tsunami, the Fukushima incident has strained life in Japan to an almost unendurable level, and although catastrophe appears to have been averted the incident has raised serious concerns about Japan's enthusiastic use of nuclear energy.
Reactors generate almost a third of the country's electricity and there are plans, already well advanced, to raise this to 50%. For the nuclear industry, the Fukushima incident could not have come at a worse time. Unravelling what happened and how close the nation came to disaster will preoccupy scientists and engineers for years.
Last night reports suggested that the emergency pumps had failed because they had been swamped by the tsunami triggered by the initial earthquake – an embarrassing failure by those who had planned the reactor's back-up systems.
Whatever the reason, the consequences were dramatic. Without pumps taking away the water that acted as the coolant, the reactors heated up and steam built up inside.
Despite the revelation that caesium had been detected, Japanese officials still claim the reactor's container was not damaged and that radiation levels have started to fall. However, the Japanese nuclear industry has a bad reputation for owning up to accidents and many observers remain cautious about accepting these claims too quickly.
Those opposed to nuclear power will not let the incident be forgotten, as Jan Beranek, head of Greenpeace's international nuclear campaign, made clear. "How many more warnings do we need before we finally grasp that nuclear reactors are inherently hazardous? The nuclear industry always tells us that situation like this cannot happen with modern reactors, yet Japan is currently in the middle of a potentially devastating nuclear crisis," he said.
