The world's media is working itself into an unedifying state of hysteria (again) following the news that radioactive water has leaked from a holding tank at the Fukushima nuclear power plant, damaged two years back by a tsunami and earthquake which led to the death and injury of more than 20,000 people - though not a single one of those casualties resulted from radiation.

However the frightful death toll which actually happened was pretty much ignored by the world's media, which chose to focus on non-existent dangers that might have resulted from radioactive material escaping from the damaged reactors at Fukushima. In the end, the nuclear apocalypse failed to appear - the scientific consensus is that absolutely no health effects due to the Fukushima radiation will ever be detectable - and the journalists reluctantly gave up.

But now they're back. We hear from Reuters today:

Japan's NUCLEAR CRISIS escalated to its WORST LEVEL since a massive earthquake and tsunami CRIPPLED the Fukushima plant more than two years ago ... nearby China said it was "SHOCKED" ... the DISASTER - the WORST nuclear accident since Chernobyl a quarter of a century earlier ... Water in the latest leak is so CONTAMINATED that a person standing close to it for an hour would receive FIVE TIMES the annual recommended limit for nuclear workers.

[Our caps. Just trying to help.]

'Nuclear crisis' - 'disaster' - FIVE TIMES the annual recommended limit? Surely this is it at last? The disaster is finally happening!

Well, no. The situation is this. The melted-down cores at the damaged reactors (the site is not "crippled", two reactors were undamaged and will return to service) are still hot - though much less hot than they were two years ago - and need to be cooled. This is done by pumping water through their buildings, then sucking it out again and putting it into holding tanks before purifying it to remove the radiation it picks up from the cores. Then it gets used again.

What has happened is that one of the holding tanks, containing water that had only been through one stage of purification, has sprung a leak and about 300,000 litres of water has got out. Almost all of this was contained by a backup dam which had been built around the tanks when they were set up (this is the nuclear industry, there is always a backup). However, "two shallow puddles" of the water got out of the dam via a rainwater drain valve which has since been sealed off.

The water is quite radioactive, and dose rates measured next to the puddles were 100 milliSieverts per hour. Nuclear powerplant workers, whose cancer rate is somewhat lower than in the general population (probably because they don't smoke so much) are allowed to sustain 50 millisievert in any one year in normal times and average doses across five years of 20 millisievert/yr.

However what Reuters haven't picked up on is that the high 100 milliSievert reading is for beta radiation only. The reading for gamma rays is only 1.5 milliSieverts per hour.

As we no doubt all recall from skool, beta radiation is not very penetrating: it can't get through human skin and it only travels a few feet through air. So you'd have to stand very close indeed to the two puddles, in them probably, for their beta rays even to reach you. A sturdy pair of wellingtons would have a good protective effect, if you should do this. As far as beta radiation is concerned, the only ways to seriously harm yourself with that water would be to get it on your exposed skin and leave it there for some time, or to drink it. This is also true of many domestic cleaning products.

The gamma hazard is noticeable, you wouldn't want to take up residence next to the pool of water, but you could work for days around it without breaching normal nuclear-worker health limits and the crews in the vicinity are being rotated regularly. Tepco is pumping all the water back into another tank pending purification, and segregating wet soil from the area. The firm told WNN that it has no indication so far of any water having got into a drainage channel or otherwise left the area.

So this is a pretty minor industrial-waste spill; thousands of more serious accidents occur every single day.

It's not global news. It's not national news. It would barely even be local news, in a sane world.

But it's not a sane world, and the media crusade against nuclear power rolls on. ®