Fast answer – an interesting concern. Those words are chosen as the human tragedy unfolds. Perhaps hundreds or thousands of people are exposed to the elements, including overnights in cold windy and wet weather. Thousands more have perished. The nuclear problems while serious in several ways are secondary shows. Food and shelter progress information is slow and tiny giving more concern and stirring painful thoughts and feelings. The Red Cross donation was done days ago. Thoughts and prayer continue.
Meanwhile the nuclear reactors are under control. The control rods seem to have been inserted – no runaway reaction has been reported. The worst fears never saw any chance to come into being. No meltdown in the unmoderated form took place and it seems not possible now. There is no Chernobyl event underway. Vast amounts of deadly radiation aren’t likely, almost impossible, but never say never. A deep blue glowing fire burning into the ground doesn’t seem to be a worthy forecast.
What has happened is the tsunami waves took out the ability to run cooling water over the working reactors and the spent fuel assemblies. When a reactor is suddenly shut down there is a tremendous amount of heat remaining in the reactor. There are tons of fuel, rod casing, control rods, apparatus, shielding, concrete and water at dry steam temperatures.
It takes a while for the heat to be bled off. Perhaps by the first of next week they’ll all be cool enough that simply residing in a pool would do.
There’s the next problem – even when under control some heat is made. Without a transfer out, the heat builds up until equilibrium with the surroundings is made. The question then becomes, will the equilibrium be cooler than the temperature required for fuel breaking out of the rod casings? Your humble writer doesn’t know, but is watching for someone credible to answer.
The things to watch for are the crews to get a fully rated cooling water flow underway and reliably running. The idea is to have no heavy elements escape. Water and light gases aren’t going to pose much if any risk. But heavier elements when driven to radioactively can give off the nasty rays. Actual fuel particalized or gasified and sent out would be tragic. It all depends on the answer of how hot the fuel rod assemblies get before equilibrium is reached.
That isn’t simple either. The roads and other access routes are shut down. Getting heavy equipment to the sites is a whole other challenge. These are big facilities; your pickup truck sized answer isn’t of much use. Railway support is still unanswered. Whole trains are reported as ‘missing’. Track damage is sure to be widespread. Road and rail are going to be needed for better than short-term quick fixes. And the quick fixes are going to be undersized in the best analysis.
A big helicopter should move some diesels and pumps. Water can be made to flow. The sources need set up and flow exits need made. While the reports don’t say, much is done and underway or the steam plumes, and emissions would be much higher.
It’s hard to get past the hysteria in the press. It makes for a bone chilling story for the un and ill informed. For the rest of us, a wish of god’s speed, good luck, decent weather and dedicated support are all we can do. The world can learn much, well engineered nuclear is safe, even in the face of a major earthquake when the engineering is done right.
There is also the lesson that earthquake preparedness isn’t enough after all. Tsunamis are also a factor deserving much more thought and attention. Redundancy in cooling while previously thought undefeatable was defeated by only a rise in water coming at great speed.
Mankind has harnessed one of physics great powers, the fission of atoms. The process, the exploitation and the use have decades of experience built up and better ideas on the drawing board. What is being learned isn’t that duly respected atomic nuclear power is dangerous in and of itself, rather it’s that the density of power, the mass involved, and the complexity haven’t been fully measured against the potential adverse impacts. The world just added or increased one more.
Energy in dense form isn’t going to go away. Whether it’s the explosive nature of gasoline or hydrogen, a lithium battery that could catch fire, an ultracapacitor delivering a huge shock, a wind turbine flying apart, or thermal solar panel fast cooking an interloper – eventually something will come along to make it dangerous and depending on how big the energy package is – might get hurt.
The main concern is to support the people working to secure the reactor and spent fuel sites. The first job though, is to find and care those without food, clothing and shelter.