The usual plan for spent nuclear fuel in the United States is to transfer it to a cooling pool and then after some time to transfer it to dry cask storage.  Eventually, the plan is to move it to a permanent storage site, although no such site is available. The proposed Yucca Mountain nuclear repository is currently off the table, and no other site is seriously being discussed.

My concern is that ability to maintain electrical supply to spent fuel pools is a risk that no one has been paying much attention to, when looking at security of spent fuel. We have just now been witnessing the problems that are occurring in Japan, when electricity was cut off from reactors at the Fukushima Daiichi plant.  The spent-fuel cooling pond has been a particular problem, because of the large amount of spent fuel in the pool, the need to keep pumping water into the pools, and the need to circulate the water in the pools. In the United States, we now have about 55,000 tons of spent fuel in spent fuel pools. This is the equivalent of 25 or 30 years of spent fuel, assuming current fuel use is 2,200 tons a year.

When a person reads about what perils the spent fuel pools are safe from, such as from this document from the US Nuclear Regulatory Commission, it talks about the pools being inside very thick steel-reinforced concrete walls with stainless steel liners located inside protected areas, and that they would be safe from impact by an aircraft or other object. The article doesn’t talk about electricity interruption as being an issue. The impression one gets from the way other perils are described, though, is that any electrical interruption is expected to be brief (hours or days), and easily handled through backup supply,  or perhaps through electricity generated by the plant itself.

It seems to me that at some point, this assumption of electricity continuing to be available is likely to be false. Continue reading →