The Situation in JapanThe Fukushima reactors have power, but they are still struggling. Yesterday, Areva confirmed that TEPCO had just asked them for help. There is no announced change in the status of the reactors. However, reports of the spread of radiation are not looking good at all. I think Capacity Factor, once again, has the best analysis so far. He concentrates on the cesium fall-out, and does not agree with the optimistic assessment from BBC.
There is no doubt that the Japanese situation is serious. The question for people in Vermont about the safety of Vermont Yankee, however, is not so much about the consequences of a huge problem, but whether our safety precautions will avoid such problems. I think they will and I have reasons to think so. Among other things, we assess risk in a different way.
How the Nuclear Industry Assesses Risk
This morning, the New York Times had an article Japanese Rules For Nuclear Plants Depended on Old Science. It turns out that when the United States went to Probabilistic Risk Assessment (PRA) for nuclear plant evaluation, the Japanese did not. (The original plant designs rarely included PRA, because it was too new at the time. Re-evaluations and uprate licensing in the United States included it.)
Because the Japanese did not use this method, The Japanese estimates of tsunami damage and their defenses against it were inadequate. Here's a quote from the article about PRA:
"The Japanese fell behind," Mr. Hardy said. "Once they made the proclamation that this was the maximum earthquake, they had a hard time re-evaluating that as new data came in."
The Japanese approach, referred to in the field as "deterministic" -- as opposed to "probabilistic," or taking unknowns into account -- somehow stuck, said Noboru Nakao,
According to the article, the NRC uses "some" aspects of PRA in evaluating plants, but could use more. EPRI did considerable research in this area (though I was not one of the researchers) and I am sure that this research is available to the NRC.
If you don't use PRA, you are likely to not assess the situation as far out on the "improbable accident scenario" spectrum as you will if you use PRA. "Deterministic risk assessment" sounds safer, but it is not.
An ounce of prevention is worth a pound of cure. We developed PRA, we use it, and we should probably use it more. It is clear to me that risk analysis in this country has been far more thorough than the analysis in Japan, and our plants are far safer.
Where was the Japanese NRC Equivalent When These Decisions Were Made?
I am going out on a limb here. I have been watching some Teaching Company videos on economics. One of the points made in the course is that the Japanese economic miracle of the 70s and 80s was due to close cooperation of industry and government. It seems to me that the entire situation of government-industry cooperation might have become too close and too cozy.
Nuclear opponents consider that the NRC is too cozy with the nuclear industry. From within the industry, however, the NRC looks much different. It looks adversarial.
Inspectors are rotated in and out of plants so they won't get friendly with the workers. Reviews of new types of plants take years, maybe decades. The NRC is truly a watchdog. This is typical of all regulation in the U.S. Regulators in the United States generally take an adversarial view of their industry. This adds to the safety (and the cost) of most industries in the United States.
The NRC has been doing a good job. I know that nuclear opponents will have a field day with this statement, but this is my opinion, and everything I read confirms it.
Graphic is The Great Wave from 36 Views of Mount Fuji by Hokusai
