Two weeks ago, I wrote an article titled Nuclear plant issues in Japan are the least of their worries that attempted to provide a realistic prediction of the worst case consequences of the one-two punch from a very large earthquake and tsunami on a large nuclear power station on the coast of Japan. It has become increasingly apparent during the past week that my view from afar was not as clear as I would have hoped. I was overly optimistic about the final consequences of the events at Fukushima Daiichi.
On the catastrophic scale of commercial nuclear energy accidents, where Three Mile Island was in second place and Chernobyl was the clear leader, Fukushima Daiichi has moved into second. It is likely that it will end up to be far closer to Chernobyl than to Three Mile Island in overall economic, public health and geographic consequences.
Update: (Posted on March 27, 2011 at 0234) The above paragraph has been changed to specify commercial nuclear energy accidents to avoid complications with discussions about accidents that have occurred in the other aspect of nuclear technology. The commercial and military sides of nuclear are complicated enough to merit two mostly separate conversations. End Update.
There has been enough damage to the plants and enough radioactive material released to pose a danger to public health for someone who does not take any precautions, though actions to evacuate, shelter and monitor contamination have minimized the actual effects – so far. There have also been a fair number of plant workers and other emergency responders who have received substantial radiation doses in the range of 100-200 mSv (10-20 Rem). Those doses are about 20% of the dose required for early signs of radiation sickness (1 Sv or 100 REM) and at the threshold where there is a statistically significant increase in long term cancer risk.
None of those heroic recovery workers has been exposed to the doses that caused radiation sickness for Chernobyl first responders, but the use of emergency limits for large numbers of recovery workers is certainly no cause for celebration among those of us who believe strongly in the importance of safely using nuclear energy. As long as the recovery workers pay attention to their monitoring devices and use caution, there is no reason to expect that there will be anyone exposed to any higher levels than those already received. Achieving the goal of acceptable individual doses will likely require rotating a rather large, well trained work force over a long period of time during the clean up operations.
The radioactive material released from the Fukushima Daiichi nuclear plant has already complicated recovery and response efforts for the area affected by the earthquake and tsunami. According to a recent story in the New York Times titled Extent of Damage to Japan’s Infrastructure Still Unclear transportation to the area is not easy, and some assistance from normal sources of expertise is being prevented because there is enough contamination to cause insurance concerns. I even heard through the grapevine that some of the US Navy ships that were off of the coast of Japan are having to engage in some complex and expensive efforts to clean up the fallout.
The final results are worse than what I predicted. Even if you are deeply steeped into the science of the health effects of low level radiation and recognize the evidence showing that doses below a certain level have a very good chance of being hormetic, it is not good to “crap up” a large geographic area with a significant mass of fission product isotopes like Cs-137 that will give off strong gamma radiation for many years. (Cs-137 has a 30 year half life.) Though I hope that the Japanese government does not take the step of permanently evacuating large, lightly contaminated areas, there is little doubt that some formerly prosperous farms and fisheries will be out of business for a very long time.
What this event has taught me is that I need to retreat a bit. I remain firm in my belief that human society needs nuclear energy and that there is no other alternative to fossil fuels that has a chance of meeting needs for reliable power. The importance of reducing fossil fuel consumption should be apparent to anyone who is following the current events in the Middle East and North Africa, whose community is a new host to gas extraction, whose mountains are being blown up, or who is concerned about the effects of dumping 20 billion tons of waste gases into our common atmosphere.
However, I am now certain that not all operating reactors are equally safe, equally well maintained, or equally well sited. I have always known that there are risks associate with nuclear energy – it is such a concentrated source of power that it is impossible to ignore just how quickly it can get out of control.
The importance of keeping fission and the resulting radioactive material under control; the importance of careful civil, mechanical, electrical and system engineering; the imperative for intensive, continuing training; and the always vital step of conducting operations and maintenance with a questioning, learning attitude was such a part of my indoctrination into the technology that I projected that attitude onto the entire enterprise. That was a mistake that I will not repeat. Humans can learn to use nuclear energy safely and effectively; we can design and operate systems that do not put the public at risk. However, that does not happen automatically.
There will always be some who are tempted to take short cuts or to fail to correct design errors because they are concerned about short term costs. The best lesson that I can take from Fukushima Daiichi is a better understanding of the scale of the potential losses. Final costs in the tens to hundreds of billions can overwhelm any short term savings in materials and construction time. It is not worth it to engage in efforts to slice a few dollars from initial costs by slimming down the defense in depth that has made most nuclear plants the safest, cleanest and most reliable energy production systems on the planet.
The good news is that no one has been building the types of boiling water reactors whose limits were exceeded at Fukushima Daiichi in many decades. Today’s Generation III and beyond reactors include numerous design features that would have provided substantial margins against the specific challenges faced at Fukushima, but that is no cause for complacency. There is always something more to learn and improve.
The Independent (March 26, 2011) Fear and devastation on the road to Japan’s nuclear disaster zone
Depleted Cranium (March 26, 2011) Putting radiation exposure into context