I’ve not written recently about the nuclear disaster in Japan following March’s earthquake and tsunami. This is largely because there has been little in the way of new news. However a few days ago an IEEE Spectrum report was released which looks at the first 24 hours at the nuclear facility following the earthquake and highlights some of the design and procedural errors which exacerbated the disaster.
Although the situation in the reactors was clearly far worse than we had been led to believe, I’ll not extract the report here: you can read a summary on-line. And it is worth reading: it’s clear, lucid, gives a flavour of just how complex these situations really are, how much wasn’t know (or wasn’t told) and how people react under extreme pressure.
What I will do is mention the six major lessons which have been highlighted by the report, with the inevitable handful of comments. This should be sufficient to show where there were errors in the design of plant and procedure. Before that there’s one important thing to note:
[The] report is based on interviews with officials from the Tokyo Electric Power Co. (TEPCO), Japan’s Nuclear and Industrial Safety Agency, the U.S. Nuclear Regulatory Commission, the International Atomic Energy Agency, local governments, and with other experts in nuclear engineering, as well as a review of hundreds of pages of official reports.
So it isn’t just make-believe; it should be good stuff. Anyway here are those lessons:
Lesson 1. Emergency generators should be installed at high elevations or in watertight chambers.
Sounds obvious, doesn’t it. But it all comes down to good risk analysis. If you aren’t expecting significant flooding it makes great sense to put plant, especially emergency generators etc., on the ground: they’re excessively heavy and when operating generate huge amounts of noise and vibration.
LESSON 2. If a cooling system is intended to operate without power, make sure all of its parts can be manipulated without power.
Again sounds obvious when stated like that, but far too easy to overlook, although good design reviews should have picked this up.
LESSON 3. Keep power trucks [mobile emergency generators] on or very close to the power plant site.
Why would we do that? Isn’t a central facility more cost effective? In this case no, it may not be!
LESSON 4. Install independent and secure battery systems to power crucial instruments during emergencies.
Same comment as for Lesson 2.
LESSON 5. Ensure that catalytic hydrogen recombiners (power-free devices that turn dangerous hydrogen gas back into steam) are positioned at the tops of reactor buildings where gas would most likely collect.
You’re never going to get a big build-up of hydrogen inside a containment building are you. Wait: isn’t that what a containment building is for? But be honest, how many of us would have thought of this?
LESSON 6. Install power-free filters on vent lines to remove radio-active materials and allow for venting that won’t harm nearby residents.
Again, see Lesson 2.
What remains clear to me is that the plant, the systems and the procedures worked correctly, and were implemented correctly, as they were designed. What failed is the 40-year-old design and the procedures which didn’t go far enough in their disaster scenario planning.
We would (and do) do much better now and will do even better as a result of this disaster. Because of its safety critical nature, the nuclear industry is like the aviation industry: every accident (and near-accident) is analysed for the underlying root cause(s) and there is a culture of incremental improvements and (where necessary/possible) of retro-fitting improvements. Notwithstanding the fact that Fukushima was (and is) a disaster, exacerbated by continuing failures in transparency and communication, I see this as a positive experience which should make nuclear power safer and more acceptable — not the reverse.
The biggest disaster is the effect on the displaced and frightened people which is largely psychological and social rather than medical; and that’s in large part down to the obfuscation and half-truths of the TEPCO and Japanese government communications. One day governments will learn that total transparency is the only safe course of action.