Nuclear Fuel and the Titanic Principle

December 6, 2013
David Wright
Former contributor

This is the second of 3 posts on spent fuel safety

In my previous post I talked about how spent fuel is piling up in cooling pools at reactors across the country. Since 100 million Americans—a third of the U.S. population—live within 50 miles of a spent fuel pool, reducing the risks to those people should be a high priority.

The NRC’s own analysis has shown that a severe accident or terrorist attack on a cooling pool that led to a loss of coolant could have disastrous effects, and that the consequences could be significantly reduced if the spent fuel was transferred to dry casks.

Essentially no one questions that storing fuel in dry casks is safer than storing it in pools. However, the NRC continues to oppose any requirements for accelerated transfers from pools to casks. That’s because it believes the probability of a severe loss-of-coolant accident at a spent fuel pool is so small that it doesn’t need to address the situation.

The problem with this thinking is what I call the Titanic Principle.

Everyone knows the story of the Titanic. Because it was considered “unsinkable,” the ship was not equipped with enough lifeboats for all the passengers. When in fact the ship did sink—due to an accident scenario that was not foreseen—1,500 people drowned.


Here’s the takeaway: The risk to the public of an accident is the probability the accident will occur times the consequence should the accident occur. If people think the probability of an accident is essentially zero, then they see the total risk as negligible even if the potential consequences are high. As a result, they may not take steps to reduce the potential consequences.

But what the Titanic example and many others show is that unexpected things happen. In some cases this is because events that are low probability do nonetheless occur. But often it is because people assessed the problem incorrectly—excluding or failing to recognize certain possibilities—so that the probability of an accident was in fact considerably higher than originally believed.

An example of the latter situation is the explosion of the Space Shuttle Challenger. Before the explosion, NASA management typically said the probability of an accident was “one in a 100,000.” Afterwards, analysis showed that the real number was one in a few hundred, which is consistent with what we’ve seen.

This is likely also the case with the NRC assessment of the vulnerability of cooling pools. The NRC analysis considers the effect of a large earthquake but does not, for example, consider the effect of a terrorist attack on the pool.

The point is that there is a lot of uncertainty about the probability of a spent fuel accident or attack that would release significant radiation, and no sound basis for the actual probability being as small as the NRC claims. As a result, assurances that a loss-of-coolant event can’t occur are simply not convincing.

Given that, the smart thing to do is to take steps to reduce the consequences should such an event occur.

Transferring a large amount of spent fuel from pools to dry casks is a sensible and practical step that could greatly reduce the consequence of a serious accident or attack.

The owner of the Titanic learned this lesson the hard way. The NRC shouldn’t have to learn it all over again.