Fukushima Daiichi: radiation levels force temporary evacuation of staff; utility fears that no.4 reactor could go critical

This morning has seen the temporary evacuation of workers fighting to keep reactors at the Fukushima Daiichi nuclear power plant, due to a spike in radiation levels. The workers returned after around an hour had passed, as radiation levels had fallen back to acceptable limits. The radiation level at the plant have put an end to attempts to dump water on the reactors via military helicopters in an effort to cool them. At present, the most worrying of the six reactors at the plant is the no.4 reactor where a fire has broken out and may have been extinguished. Water levels at this reactor are said to be dropping. There are plans to use a police water cannon truck to cool the spent nuclear fuel pool at the reactor. TEPCO has reported elevated temperatures at Reactors 5 and 6 which were offline during the tsunami and earthquake. Water is currently being poured into them. Partial core meltdowns are thought to have taken place at reactors 1 and 2 and 70% of fuel rods at reactor 1 have been damaged, compared to 33% at reactor 2.

French authorities have urged its citizens in Tokyo to leave or head towards the south of the country, suggesting that the international community is losing confidence in the ability of TEPCO and the Japanese government to bring the situation under control.

Experts now believe that the situation has overtaken the Three Mile incident in severity which occurred in Pennsylvania in 1979, which saw the half of one reactor core melt due to a loss of coolant.

In the absence of a full meltdown, the impact on neighbouring countries will likely be muted, in part due to forecasts of rain and snow for the region. Agencies in Russia and Singapore have reported no changes in radiation levels.

The crisis has knocked JPY1.93tn (US$24bn) off TEPCO’s market value, with shares falling by 57% in three days, while the cost of insuring the company debt has risen by nearly nine-fold since the March 1 earthquake. The utility is required to carry liability insurance of around JYP120bn (US$1.5bn). Should costs from the disaster be in excess of this amount, the company might receive government assistance.