Original URL: http://www.theregister.co.uk/2011/03/18/fukushima_friday/

Fukushima one week on: Situation 'stable', says IAEA

Shameful media panic very slowly begins to subside

By Lewis Page

Posted in Science, 18th March 2011 12:56 GMT

The situation at the Fukushima Daiichi nuclear powerplant in Japan, badly damaged during the extremely severe earthquake and tsunami there a week ago, continues to stabilise. It is becoming more probable by the day that public health consequences will be zero and radiation health effects among workers at the site will be so minor as to be hard to measure. Nuclear experts are beginning to condemn the international hysteria which has followed the incident in increasingly blunt terms.

Seawater cooling of the three damaged reactor cores (Nos 1, 2 and 3) at the site continues. US officials and other foreign commentators continued to remain focused on a spent-fuel storage pool at the No 4 reactor (whose fuel had been removed and placed in the pool some three months prior to the quake).

Despite this, operations by Japanese powerplant technicians, military personnel and emergency services at the site focused instead on cooling the spent-fuel pool at the No 3 building, and on restoring grid electrical power at the plant. Japanese officials continued to contend that water remained in the No 4 pool and the situation there was less serious than that at No 3. Police riot vehicles mounting powerful water cannon and fire trucks were used to douse the spent-fuel pool at No 3 with water, causing steam to emerge – confirming that some cooling at least was being achieved. One of the fire trucks was reportedly lent by US military units based locally, though operated by Japanese troops.

World Nuclear News reports that radiation levels have generally decreased across the plant, though they remain hazardous in the immediate area of reactors 2 and 3; levels also climb temporarily when technicians open valves to vent steam from the damaged cores in order to allow fresh seawater coolant to be pumped in, prompting teams to retreat before venting is carried out. Nonetheless 180 personnel are now working within the site where and when radiation levels permit them to do so safely.

An external power line has now been laid out to the plant and latest reports indicate that this will be connected to its systems by tomorrow: final hookup has been delayed by steam-venting operations from the cores. Powerplant technicians hope that this will restore cooling service to reactor cores and spent-fuel pools across the plant, in particular to the pools at reactors 3 and 4. If normal water levels can be restored to the pools high levels of radiation above and immediately around the buildings will be cut off by the liquid's shielding effect. The buildings' roofs would normally help with this, but both have been blown off in previous hydrogen explosions.

Meanwhile, plant operator TEPCO said that on-site diesel generation serving units 5 and 6 – which are safely shut down, but which also have spent fuel in their storage pools – has been restored. The plant's diesels were mostly crippled by the tsunami which followed the quake: the wave was higher than the facility's protective barriers had been designed for. The prospect of any trouble at these reactors now seems remote.

The IAEA seems to accept that things are settling down: a senior official at the agency tells Reuters that the situation is now "reasonably stable".

Radiation readings at the site boundary remained low through Friday morning in Japan, dropping to 0.26 millisievert/hour. Personnel at the site are normally permitted to sustain 20 millisievert in a year: this has been raised to 250 millisievert owing to the emergency.

Normal dosage from background radiation is 2-3 millisievert annually: a chest CT scan delivers 7 millisievert. The highest radiation level detected anywhere beyond the site was a single brief reading of 0.17 millisievert at the boundary of the evacuation zone, but on average (Japanese government PDF/72KB) readings at the zone boundary are hardly above background.

Occasional brief readings of slightly heightened radiation – occasionally reported in scaremongering fashion as "10x normal" – have been detected as far afield as the outskirts of Tokyo, but these are insignificant in a health context. Even if they persisted unbroken for a year, local dosages at such a level would be no more than powerplant workers are allowed in normal times: and nuclear powerplant workers' cancer rate is actually lower than in the general population. Measurable blips in background radiation may be detectable around the world in coming weeks, and will no doubt be heavily reported on, but they will be more insignificant still.

Top US nuke engineer slams US gov advice on evacuation

A single very brief spike of 400 millisievert/hr, recorded by an instrument near reactor No 3 following an explosion on Tuesday, is still being widely reported as if it were the current level at the site, probably not helped by a poorly translated and somewhat belated TEPCO press release issued yesterday, which mentions it. Nonetheless, levels even adjacent to the stricken reactors have seldom been above 4 millisievert/hr, and much lower elsewhere in the plant. Higher levels are detected by aircraft above the buildings because the steel-lined rooftop pools are shining short-ranged radiation straight up: this is why helicopters do not linger above them.

Overflights of the area by specially equipped US radiation-monitoring aircraft, conducted with Japanese permission, have confirmed the Japanese government's assessment that radiation levels beyond the powerplant site itself offer no cause for concern. The New York Times reports (NB – this article has already changed several times since it was published – quote correct as this is written):

While the findings were reassuring in the short term, the United States declined to back away from its warning to Americans there to stay at least 50 miles from the plant, setting up a far larger perimeter than the Japanese government had established. American officials did not release specific radiation readings.

The renowned US nuclear engineer Ted Rockwell, who quite literally wrote the book on reactor safety, has harsh words for this position. He writes:

[Consider] the Three Mile Island (TMI) incident, where 10 to 20 tons of the nuclear reactor melted down, slumped to the bottom of the reactor vessel, and initiated the dreaded China Syndrome, where the reactor core melts and burns its way into the earth ... In the real world, the molten mass froze when it hit the colder reactor vessel, and stopped its downward journey at five-eights of an inch through the five-inch thick vessel wall.

And there was no harm to people or the environment. None.

Yet in Japan, you have radiation zealots threatening to order people out of their homes, to wander, homeless and panic-stricken, through the battered countryside, to do what? All to avoid a radiation dose lower than what they would get from a ski trip.

Certainly the cores at Fukushima seem likely to come through in much better condition than the one at Three Mile Island did, offering even less chance of dangerous radioisotopes being emitted in significant quantities. As to the spent rods in the cooling pools, it seems to be far from established that they present any risk of melting down at all, or of major emissions to atmosphere if they did. The Japanese Nuclear Energy Institute says:

Even if the water level in the pools was to decrease sufficiently so that the fuel were exposed to air, the same level of overheating that can occur in a reactor accident would not occur in the used fuel pool because the used fuel assemblies in the pool are cooler than the assemblies in the reactor. It is highly unlikely that used fuel temperatures could reach the point where melting could occur, although some damage to the cladding cannot be ruled out.

Main killer in all this? The panic

Some more details on casualties thus far have been released, reported by WNN. It turns out that there has been one confirmed death, but not at the Daiichi plant at all: a worker who was in a crane cab at the separate Fukushima Daini plant (where all reactors are now confirmed to be safely in cold shutdown) was killed when the quake hit. Two more workers, this time at the Daiichi plant, are still listed as missing since the quake and tsunami hit. Six more required medical help following the quake, one suffering two broken legs.

A further 15 non-radiological injuries have resulted from hydrogen explosions at the site, though some of these were minor in nature and the individuals concerned returned to duty shortly after.

As to radiation-related issues, there has been one case of measurable significance. Earlier in the week when workers were still limited to a total dose of 100 millisievert, one individual breached this limit during venting operations and consequently was evacuated to hospital. As noted above, personnel are now permitted to sustain doses of 250 millisievert.

The Japanese people, rightly, are hailing the personnel at the site as heroes. Not the least impressive aspect of their performance is the way they appear to be tackling the situation with such professionalism as not to carelessly risk their own well-being.

In summary it appears more and more that health consequences from reactor damage will be extremely minimal even for workers at the site. It will now be a surprise if anyone who has not been inside the plant gates this week is affected by the situation at at all – apart from all the people worldwide who have been taking iodide pills or eating salt unnecessarily. There may also be measurable psychological health effects from the global media-driven hysteria surrounding the situation, of course.

"Experience from past nuclear incidents has shown that the stress and panic caused by these events can be as bad as, or worse than, the direct threat from radiation," according to Dr Jim Smith of Portsmouth uni's School of Earth and Environmental Sciences.

Analysis

The Fukushima reactors actually came through the quake with flying colours despite the fact that it was five times stronger than they had been built to withstand. Only with the following tsunami – again, bigger than the design allowed for – did problems develop, and these problems seem likely to end in insignificant consequences. The Nos 1, 2 and 3 reactors at Daiichi may never produce power again – though this is not certain – but the likelihood is that Nos 4, 5 and 6 will return to service behind a bigger tsunami barrier.

The lesson to learn here is that if your country is hit by a monster earthquake and tsunami, one of the safest places to be is at the local nuclear powerplant. Other Japanese nuclear powerplants in the quake-stricken area, in fact, are sheltering homeless refugees in their buildings – which are some of the few in the region left standing at all, let alone with heating, water and other amenities.

Nothing else in the quake-stricken area has come through anything like as well as the nuclear power stations, or with so little harm to the population. All other forms of infrastructure – transport, housing, industries – have failed the people in and around them comprehensively, leading to deaths most probably in the tens of thousands. Fires, explosions and tank/pipeline ruptures all across the region will have done incalculably more environmental damage, distributed hugely greater amounts of carcinogens than Fukushima Daiichi – which has so far emitted almost nothing but radioactive steam (which becomes non-radioactive within minutes of being generated).

And yet nobody will say after this: "don't build roads; don't build towns; don't build ships or chemical plants or oil refineries or railways". That would be ridiculous, of course, even though having all those things has actually led to terrible loss of life, destruction and pollution in the quake's wake.

But far and away more ridiculously, a lot of people are already saying that Fukushima with its probable zero consequences means that no new nuclear powerplants should ever be built again. ®

Personal bootnote

As one who earns his living in the media these days, I can only apologise on behalf of my profession for the unbelievable levels of fear and misinformation purveyed this week. I have never been so ashamed to call myself a journalist.