Just when it seemed things might be under control at Japan's Fukushima Daiichi nuclear power plant, we find they are worse than ever.

Immeasurably worse.

Massive quantities of radioactive liquids are now flowing through the shattered reactor site into the Pacific Ocean. And their make-up is far more lethal than the "mere" tritium that has dominated the headlines to date.

Tokyo Electric Power Co (Tepco), the owner/operator, and one of the world's biggest and most technologically advanced electric utilities, has all but admitted it cannot control the situation. Their shoddy performance has prompted former US Nuclear Regulatory Commissioner Dale Klein to charge: "You don't know what you are doing."

The Japanese government is stepping in. But there is no guarantee, or even likelihood, it will do any better.

In fact, there is no certainty as to what's causing this out-of-control flow of death and destruction. Some 29 months after three of the six reactors exploded at the Fukushima Daichi site, nobody can offer a definitive explanation of what is happening there or how to deal with it.

The most cogent speculation now centers on the reality that, simply enough, water flows downhill.

Aside from its location in an earthquake-prone tsunami zone, Fukushima Daichi was sited above a major aquifer. That critical reality has been missing from nearly all discussion of the accident since it occurred.

There can be little doubt at this point that the water in that underground lake has been thoroughly contaminated.

In the wake of the March 11, 2011 disaster, Tepco led the public to believe that it had largely contained the flow of contaminated water into the Pacific. But now it admits that not only was that a lie, but that the quantities of water involved, apparently some 400,000 gallons per day, are very large.

Some of that water may be flowing from the aquifer. Much of it also, simply enough, flows down Japan's steep hillsides, through the site and into the sea.

Until now the utility and regulatory authorities have assured an anxious planet that the contaminants in the water have been primarily tritium. Tritium is a relatively simple isotope with a 12.3-year half-life. Its health effects can be substantial, but its atomic simplicity has been used to proliferate the illusion that it's not much to worry about.

Reports now indicate the outflow at Fukushima also includes substantial quantities of radioactive iodine, cesium and strontium. That, in turn, indicates there is probably more we haven't yet heard about.

This is very bad news.

Iodine-131, for example, can be ingested into the thyroid, where it emits beta particles (electrons) that damage tissue. A plague of damaged thyroids has already been reported among as many as 40% of the children in the Fukushima area. That percentage can only go higher. In developing youngsters, it can stunt both physical and mental growth. Among adults it causes a very wide range of ancillary ailments, including cancer.

Cesium-137 from Fukushima has been found in fish caught as far away as California. It spreads throughout the body, but tends to accumulate in the muscles. Strontium-90's half-life is around 29 years. It mimics calcium and goes to our bones.

That these are among the isotopes being dumped into the Pacific is the worst news to come from Japan since Hiroshima and Nagasaki, whose bombings occurred 68 years ago this week, and whose fallout has been vastly exceeded at Fukushima.

Indeed, Japanese experts have already estimated Fukushima's fallout at 20-30 times as high as the 1945 bombings. This latest revelation will send that number soaring.

The dominant reality is this: there is absolutely no indication how or when this lethal outflow will stop. Thus far Tepco has built scores of tanks on the site to contain whatever contaminated water they can capture. But they by no means are getting all of it, and they are running out of space. Some of the tanks, of course, have already sprung leaks.

There is no clear idea whether this outflow is accelerating. Tepco has injected chemicals into the ground meant to harden and form a wall between the reactors and the sea. There's also a surreal discussion of super-cooling a part of the site to conjure up a wall of ice.

But water has a way of flowing around such feeble devices.

We may yet hear that this massive outflow is a temporary phenomenon, but that's not likely.

The dire reality is that the site is still unpredictably radioactive. It remains unclear what has happened to the melted cores of the three exploded reactors. The recent appearance of a steam plume has raised the spectre that fission may still be occurring somewhere in the area.

It is also unclear what will happen to the hundreds of tons of spent fuel perched precariously in a pool 100 feet in the air above Unit Four. Sustaining that cooling system until the rods can be removed, and it's unclear when that will happen, is a major challenge. Should the inevitable earthquake come before that's done, and should those rods go crashing to the ground where they and their zirconium cladding could ignite in the open air, the consequences could only be described as apocalyptic.

Through it all, Japan's new pro-nuclear administration has been talking of re-starting the 48 reactors that remain shut since Fukushima. Tepco has been among the utilities pushing to resume operations at its other plants. In the US, there is talk of atomic reactors somehow solving the global warming crisis.

But what we now know all too well at Fukushima is that the world's worst atomic catastrophe is very far from over. The only thing predictable is that worse news will come. And that when it does, our increasingly fragile planet will be further irradiated, at immeasurable cost to us all.