By Ted Rockwell
How are Permissible Radiation Limits Set?
How Much is Science, How Much “Prudence”?
U.S. Regulatory Report NCRP-136 examined the question of establishing permissible radiation limits. After looking at the data, it concluded that most people who get a small dose of nuclear radiation are not harmed by it, and in fact are benefited. That’s what the science said: Most people would benefit by receiving more radiation.
But curiously, the report’s final conclusion was just the opposite. It recommended that our regulations should be based on the premise that any amount of radiation, no matter how small, should be considered harmful. It made that recommendation just to be “conservative” or “prudent.”
Let’s think about that. Why is it prudent do just the opposite of what the science indicates? Why is exaggerating a panicky situation considered prudent? I’ve never seen a good answer to that question. Whatever the reasoning, that’s where we’ve ended up.
We’ve had three uncontrolled releases of radioactivity from serious malfunctions of nuclear power plants: Three Mile Island, Chernobyl, Fukushima. In each of these, fear of radiation proved to be much more harmful than the effects of radiation itself. And announcing that no amount of radiation is small enough to be harmless was certainly effective in creating and nurturing phobic fear of radiation, when none was justified by the facts.
In addition, the problem is aggravated by the fact that we’ve been told for sixty years (two human generations) that nuclear terror is infinitely more dreadful than any non-nuclear threat, particularly when you blur the distinction between power plants and bombs.
But what Fukushima tells us that this abstract, academic position looks very different when you’re telling people they can’t go home – perhaps for years, because, well, it seems more prudent that way, even though radiation hasn’t actually hurt anyone there.
Radiation expert Professor Wade Allison, author of “Radiation and Reason,” has cast the question in a new light. He suggests, let’s set the permissible radiation limit the same way we set all other safety limits. Not by asking how little radiation we can get by with, but how much can we safely permit? There’s no intention of lowering the safety margin, and it will not be lowered. That’s not the issue. It’s a matter of working with the scientific data, rather than from a generic fear not supported by the science.
Prof. Allison concludes that setting the permissible radiation limit, with a good margin of safety, results in an annual permissible level about 1000 times the current figure.
To see a brief video of Prof. Allison’s talk to the Japanese people, click on: