The situation at Fukushima Daiichi nuclear plant now has Japan officially on maximum alert.

To give an idea of just how much highly contaminated water they must try to remove before any more work can continue on the damage plant: Just one of the tunnel/trenches under the reactors holds 6,000 cubic meters of contaminated water, more than two Olympic swimming pools.

Chief Cabinet Secretary Edano Yukio says they have no choice but to keep pumping water in, to keep the reactors from melting down.