TOKYO, March 16, 2011 (AFP) - Japan's nuclear crisis deepened Wednesday with another fire at a quake-hit plant, fears a reactor containment vessel may have been damaged, and a radiation spike that forced the temporary evacuation of workers.
Chief government spokesman Yukio Edano reported a sudden and brief rise in radiation levels at the stricken Fukushima No. 1 plant on Japan's northeast coast.
He said the likeliest explanation was an emission of radioactive steam from the containment vessel, although that had not been confirmed.
|This handout picture, released from Tokyo Electric Power Co (TEPCO) on March 16, 2011 shows damaged third (L) and fourth reactors of the TEPCO Fukushima No.1 power plant in Fukushima north of Tokyo. AFP|
The nuclear safety agency said Edano's comments suggested there had been damage to the vessel. "The container has an exhaust hole but other than that, no gas should be coming out," a spokesman said.
A team of US experts headed to the country to lend expertise on the crisis centred on the 40-year-old plant, located 250 kilometres (155 miles) northeast of Tokyo, while hundreds of other foreigners headed out.
Scared Tokyo residents filled outbound trains and rushed to shops to stock up on face masks and emergency supplies amid heightening fears of radiation headed their way.
Engineers have been battling a nuclear emergency since a massive earthquake and tsunami knocked out cooling systems last Friday and fuel rods began overheating.
There have been four explosions and two fires at four of the plant's six reactors, and radioactive material has been released into the atmosphere. Two workers have been reported missing since the disaster struck.
Tens of thousands of residents have been evacuated from a 20 kilometre (12 mile) zone around the plant, and thousands of others within a 20-30 km radius were urged to stay indoors.
Edano said radiation levels at the plant rose sharply Wednesday, before falling again, but that there was no need to expand the evacuation area around the plant based on current data.
The nuclear safety agency said the level around the plant peaked at 6.4 millisieverts at around 10.45 am (0145 GMT). Within 10 minutes it had fallen to 2.9 millisieverts.
A spike in radiation levels near the reactors on Tuesday ranged from 30 to 400 millisieverts. A single dose of 1,000 millisieverts -- or one sievert -- causes temporary radiation sickness such as nausea and vomiting.
Workers battling to contain the crisis were all temporarily evacuated because of the rise in radiation levels Wednesday.
A pre-dawn blaze broke out at the number-four reactor but reportedly went out on its own accord 30 minutes after being spotted, the atomic safety agency said.
But white smoke or steam was seen above the stricken plant around 10:00 am (0100 GMT). Edano said there had been no new explosion there.
Eight experts from the US Nuclear Regulatory Commission were to arrive Wednesday to advise on managing the situation, the foreign ministry said. It was not immediately known if they would go to Fukushima.
The government had earlier reported apparent damage to the suppression pool surrounding the base of the containment vessel of the number-two reactor.
Elsewhere at the plant, the nuclear safety agency -- citing information from TEPCO -- said 70 percent of the fuel rods at the number-one reactor and 33 percent at the number-two reactor are believed damaged judging by radiation levels.
It was possible the rods' metal cladding had melted, exposing the radioactive core, a spokesman said.
Seawater is being pumped around the fuel rods in a desperate attempt to cool them down, but there are also fears about pools which hold spent rods.
If water in the pools evaporates, the spent rods would be exposed to the air and radioactive material would be released into the atmosphere.
TEPCO initially considered spraying boric acid over the containment pool at reactor number four but is now leaning towards pumping it through fire engines, the safety agency spokesman said.
France's Nuclear Safety Authority said the disaster now equated to a six on the seven-point international scale for nuclear accidents, ranking the crisis second only in gravity to Chernobyl.
Europe's energy commissioner Guenther Oettinger went further and dubbed the nuclear disaster an "apocalypse", saying Tokyo had almost lost control of events at the Fukushima plant.
"There is talk of an apocalypse and I think the word is particularly well chosen," he said in remarks to the European Parliament.