It is now nearly four weeks since the earthquake and tsunami hit Japan's northeast coast, but the crisis at the crippled the Fukushima Daiichi power plant is far from over.
A spokesman for Tokyo Electric Power (TEPCO) told Reuters that the leak of radioactive waste into the sea from No 2 reactor has now been stopped after technicians injected a mixture of liquid glass and a hardening agent.
The leak had been discovered on Saturday and early unsuccessful attempts to stem this had been made with cement, absorbent polymer, rags, sawdust and even newspaper.
The plugging of the leak is obviously a major breakthrough, but it must be tempered by the fact that engineers still need to pump 11.5 million litres of contaminated water back into the ocean because they have run out of storage capacity at the facility. This will continue until Friday. Experts insist that this water has a low level of radioactivity and pumping it into the ocean will pose no health hazard.
Meanwhile the damaged reactors are far from being under control. Workers are still struggling to restart the cooling pumps that recycle the water in four damaged reactors. Until those have been fixed, water must be pumped in from outside to prevent overheating and meltdowns.
This process creates more contaminated water. Reuters reports that the water remaining in the reactors is five million times legal limits and this water has to be stored somewhere else, or released into the sea.
The Guardian reports that 60 million litres of highly contaminated water remain in the plant and there is no longer anywhere for it to be stored. Murray Jennex of San Diego University specialises in nuclear containment and he told Reuters that what they were going to have to release is likely to be highly radioactive, which could lead to a very ugly political situation within a week.
Currently a floating tanker is being converted to hold contaminated seawater and this is due to arrive at the plant site by 16thApril. TEPCO also plans to build tanks to hold radioactive water, but time is running out.
It is expected to be months before the reactors finally cool down and years before the damaged ones can be dismantled. TEPCO has said that it will decommission four of the six reactors at the plant.
Reuters reports TEPCO saying that on Wednesday night there was concern about the build-up of hydrogen gas in No 1 reactor and engineers injected nitrogen gas to prevent an explosion. It was after hydrogen explosions ripped through reactors 1 and 3 early on in the crisis that high levels of radioactivity escaped into the air.
The Kyodo news agency quotes a government source as saying that plans are being considered to cover the damaged reactors with special sheets to halt radiation leaks, but levels of radiation are currently so high that they cannot be installed before September.
Meanwhile the effects of the world's costliest natural disaster continue to be felt. 28,000 people are dead or missing and thousands have been left homeless and Japan is faced with a damages bill that could top $300 billion.